A number of reports have identified the Colorado River basin as one of the areas most vulnerable to climate change, second only perhaps to Alaska, with its receding coastlines. The basin remains in a multi-year drought that began in 1999 and is only likely to become hotter and more arid as the impacts of climate change take hold. Already, the river’s two main reservoirs, Lake Powell and Lake Mead, are only 45 and 50 percent full, respectively. Unless current levels of consumption change soon, there is a 50 percent chance that their water levels could drop below the outlet pipes that as early as 15 years from now—effectively rendering the reservoirs dry.

But the convergence of unsustainable consumption and climate change just might push the water situation in western states around the proverbial bend. And a look at research from recent years underscores the stern warning in the U.S. Global Change Research Program report released by the Obama administration last week that, “Climate change has already altered, and will continue to alter, the water cycle, affecting where, when, and how much water is available for all uses.”

According to a 2007 report by the National Research Council, the basin has grown hotter than any other region in the country over the last three decades. Recent global climate model estimates now project temperature increases of 2 to 4°C by mid-century. The warming has cut into the river’s main input, the snow that falls in the mountains of Wyoming, Utah, and Colorado during the winter and is naturally stored in the form of snowpacks. Reports of below-average snowpack sizes have become more and more common over the last decade, with 2006 marking the advent of record or near-record lows in New Mexico, southern Colorado, and Arizona. Over 90 percent of reporting stations in Arizona were snow-free on January 1—easily the highest figure in the past 40 years. The basin’s snow has also begun to melt earlier in the spring, depriving users, particularly farmers, of the water when they need it most.

In a study detailed last month in the Proceedings of the National Academy of Sciences, Tim P. Barnett and David W. Pierce of the Scripps Institution of Oceanography in La Jolla, California, predicted that climate change could eventually reduce the flow of the river by 10 to 30 percent. Such a significant reduction would result in scheduled water deliveries that go missing 60 to 90 percent of the time by mid-century, potentially creating shortfalls that reach upwards of 1 billion cubic meters per year. That’s about four times the residential water use of the citizens of Denver in 2006.

Though the numbers seem large, Barnett and Pierce believe these delivery shortfalls can mostly be managed through conservation, reuse, transfers, and other measures. Population growth and natural climate variability could complicate these efforts, however, and they caution that the water budget model used by the United States Bureau of Reclamation to plan future deliveries could, by overestimating current river flows, give planners a false sense of complacency.

While the scientists have spoken clearly, it remains to be seen whether western policymakers will react in time and make the crucial reforms needed to avert disaster. Many of the thorniest issues—how to divide water use between municipal and agricultural users, for instance, or how to balance environmental concerns with industry needs—are unresolved, and current initiatives seem either too timid or too risky to succeed.

In California, proponents of desalination are aggressively pushing the process as a potential solution to the state’s worsening water deficits, with plans already in place to build up to 20 new plants. The proposed facilities have encountered stiff resistance from a range of environmental groups, which have assailed them as being too expensive, energy-inefficient, and dangerous to marine life. More cost-effective and practical measures, such as water reuse, water protection and conservation, should take precedence, they argue.

California’s dilapidated water delivery system recently received a $260 million boost from Interior Secretary Ken Salazar as part of the federal stimulus package. The money will primarily be used to build a screened pumping plant, which will protect fish at a dam located on the Sacramento River and increase the amount of water it can dispense to about 150,000 acres of farmland, and to provide relief for the drought-wracked Central Valley.

Several cities have also been experimenting with water rationing and modified water pricing schedules. Los Angeles, which is entering its third year of drought, has just increased prices in an effort to coax residents into reducing their consumption by 15 percent. The city’s Department of Water and Power will also offer residents who replace their grass lawns with drought-resistant plants, mulch, or water-permeable hardscapes a small cash incentive: $1 per square foot. San Diego, for its part, will only allow its residents to water their lawns three days a week and only for ten minutes at a time.

Though promising, especially if planners can implement them on a larger scale, these measures will likely lack the oomph necessary to make a significant dent in the West’s water crisis. More promising is a major water protection initiative for the Colorado River recently proposed by Lake Havasu City Mayor Mark Nexsen at a House Natural Resources Subcommittee hearing. Nexsen called for a comprehensive, coordinated approach to water quality management that would bring together the relevant local and federal agencies that oversee the Lower Colorado River to tackle the threats posed by invasive species, nonpoint source pollution, pharmaceuticals, and wastewater discharge. With appropriate funding, the program would improve the Lower Colorado River’s ecology and increasing the amount of water available to be used.

Other proposed measures could involve the transfer of water between wet areas and dry ones. A study published last month in the Journal of Climate found that, while many of the nation’s rivers would see greatly reduced flows in the coming decades, some, particularly in the Midwest, would see increased flows, thanks to greater precipitation.

Ultimately, we will simply have to make do with less water. As we’re learning to manage our carbon footprints, we will also have to learn how to manage our water footprints, by consuming less and more intelligently.

Jeremy Jacquot is a graduate student in marine environmental biology at the University of Southern California and is a contributing writer for Discover, Popular Mechanics, and DeSmogBlog.

But the recommendations from existing research are relevant now more than ever, and what we know already about the relationship between health and climate is invaluable as communities in the United States and around the world adapt to a warming world.

Researchers first began to speculate that global warming could facilitate the spread of infectious diseases during the 1990s. Scientists understood that malaria, dengue fever, and other vector-borne diseases—those carried by mosquitoes, ticks, sandflies and other organisms—were endemic to tropical and subtropical regions, and thought their transmission rates were particularly sensitive to slight fluctuations in temperature and humidity. They theorized that rising temperatures and humidity, among other shifting climate patterns, could increase the number of cases by expanding the diseases’ reach.

Several studies done at the time examined the effects of global warming on disease transmission in Africa and found strong temperature dependencies in the correlations between disease rates and weather variations over spans of both weeks and years, and in the close geographic associations between major climate indices and the distributions of the diseases. Though most of these studies ultimately failed to pinpoint the exact causes of the increase in disease spread, the researchers involved concluded that continued warming would have a strong impact on pathogen development and disease transmission, increasing the risk of future outbreaks.

In 1997, the U.S. Global Change Research Program commissioned the creation of the National Assessment of the Potential Consequences of Climate Variability and Change to study the future impacts of climate change on the country and on several major national sectors, including health, over two periods-through 2030 and through 2100. The report, published in 2001, concluded that the number of deaths and illnesses resulting from extreme weather events, air pollution, and water- and foodborne diseases would likely increase, and that certain populations—particularly the poor, the elderly, and children—would face the most severe consequences.[1]

Heat waves would become more common and more severe, as would natural disasters like floods and storms. The combined effects of higher temperatures and increased pollutant emissions in urban areas could worsen air quality by enhancing the formation of ground-level ozone and spurring the use of air conditioning and other fossil fuel-dependent technologies. Changes in temperature, rainfall, and humidity could affect water quality by increasing the flow of urban and agricultural run-off to coastal waters and freshwater bodies, making it easier for waterborne disease agents like bacteria and viruses to spread. Similarly, weather variations could increase the number of cases of vector- and rodentborne illnesses by creating conditions amenable to the disease agents’ growth.

They cited the example of hantaviruses, a group of viruses carried by several rodent species and transmitted to humans through contact with feces and through the air, which caused an outbreak of Hantavirus Pulmonary Syndrome in the southwest when a previously undocumented strain, called Sin Nombre (“Without a Name”), emerged in 1993. The outbreak was attributed to a surge in the local mouse population that was caused by an increase in their food supply; this, in turn, was attributed to unusually high precipitation brought about by the 1991-1992 El Niño event.

To counter these trends and prepare for the worst, the authors recommended a series of adaptive responses. These included weather watch systems, improved disease monitoring and prevention programs, more vaccines, more robust sanitation systems, and better targeted research, among others. “Vigilance in the maintenance and improvement of public health systems and their responsiveness to changing climate conditions and to identified vulnerable subpopulations should help to protect the U.S. population from any adverse health outcomes of projected climate change,” they concluded.

Though the report may now seem dated, many of its conclusions and recommendations are as relevant ever. As its authors predicted, the United States has since experienced more heat waves and extreme weather events, including the devastating Hurricane Katrina (which a warmer Gulf of Mexico helped strengthen), though the federal and state governments have yet to implement many of their suggested adaptive responses.

In 2005, Paul R. Epstein of Harvard Medical School, one of the foremost experts on the relationship between climate and health, warned in an editorial in The New England Journal of Medicine that the consequences of further warming could be devastating to human well being worldwide.[2] Floods, like those that followed Hurricane Katrina, often create “disease clusters” by forming new mosquito-breeding sites, driving rodents from their burrows, and dumping large amounts of pathogens, nutrients, and chemicals into waterways. Prolonged droughts and heat waves, like those seen in the southwest, lay the ground for more wildfires, which can result in deaths from burns and respiratory illness, and draw on the region’s already overdrawn water supplies. One of the greatest threats to human health could come from an increase in the number of illnesses affecting wildlife, livestock, crops, and other organisms-illnesses that we’ve now realized can sometimes make the leap over to humans.

His conclusion echoed many of the points made in the 2001 report:

All in all, it would appear that we may be underestimating the breadth of biologic responses to changes in climate. Treating climate-related ills will require preparation, and early-warning systems forecasting extreme weather can help to reduce casualties and curtail the spread of disease. But primary prevention would require halting the extraction, mining, transport, refining, and combustion of fossil fuels-a transformation that many experts believe would have innumerable health and environmental benefits and would help to stabilize the climate.

The United States is on its way to enacting the country’s first meaningful climate legislation, which could, as Epstein and other scholars have noted in more recent work., pay some of its largest dividends in the area of health. Moreover, the Environmental Protection Agency’s decision to regulate carbon dioxide and other greenhouse gases as dangerous pollutants under the Clean Air Act signals the new administration’s intent to take the joint matters of climate change and health seriously.

As a recent study co-published by The Lancet and the University College London Institute for Global Health Commission, entitled “Managing the health effects of climate change” noted: “The move to a low-carbon economy will have global health benefits from both a reduction in the health effects of climate change and improvement in human lifestyles, and these must be emphasized.” The Obama administration’s embrace of this goal will jumpstart a clean-energy economy and simultaneously ensure a healthy society.

Jeremy Jacquot is a graduate student in marine environmental biology at the University of Southern California and is a contributing writer for Discover, Popular Mechanics, and DeSmogBlog.

Notes

[1] Patz, J.A. et al, “The Potential Health Impacts of Climate Variability and Change for the United States: Executive Summary of the Report of the Health Sector of the U.S. National Assessment,” Journal of Environmental Health 64(2)(2001): 20 – 28.

[2] Epstein, P.R, “Climate Change and Human Health,” The New England Journal of Medicine, 353(14)(2005): 1433 – 1436.

Wherever you stand on this debate, it’s hard to deny that, as a whole, our national fervor for biofuels has cooled considerably over the past year-as has interest in the multitude of ethanol start-ups that sprung up to cash in on the craze, many of which now find themselves squeezed by the recession or, worse, bankrupt. What started as an attempt to make the country less reliant on foreign sources of fossil fuels in the aftermath of the September 11 attacks soon morphed into a mega-industry, buoyed by an administration and Congress eager to show off their “green” credentials.

Many congressmen saw it as a golden opportunity to bolster their electoral fortunes by pouring millions into politically influential agristates. In 2004, a young Democratic senator from Illinois, Barack Obama, praised corn ethanol as a vital component of our energy policy. “Instead of continuing to link our energy policy to foreign fields of oil, it should be linked to farm fields of corn,” he said during a Senate speech.

In the summer of 2005, Congress passed the Energy Policy Act of 2005, which required refiners to blend 7.5 billion gallons of biofuels into gasoline by 2012; European Union nations followed suit in short order, pledging to obtain 10 percent of their transport fuels from biofuels by 2010. At the peak of the boom, investors were pouring tens of millions into a range of flashy new ventures, each more ambitious than the last. The overwhelming critical, and popular, reception that greeted Al Gore’s An Inconvenient Truth only made the appeal of green, renewable forms of energy more irresistible.

Even as refiners were busily erecting new plants to ride the investment craze, some among the scientific and environmental community were already beginning to sound the alarms about biofuels’ risks. For one, many pointed out that corn ethanol’s vaunted prowess in reducing greenhouse gas emissions was erroneous; indeed, when the fuel costs of growing corn and producing ethanol are taken into account, corn ethanol’s carbon footprint is actually larger than that of gasoline. To make matters worse, ethanol production is a terribly inefficient process, and shifting more land to cornfield has many detrimental environmental impacts, including increased soil erosion, higher fertilizer and pesticide use, and higher water consumption.

At first, these findings did little to diminish the enthusiasm for biofuels. Aside from some moderate hand-wringing, politicians kept the subsidy taps flowing; most investors didn’t even skip a beat. It wasn’t until global wholesale food prices began their sharp rise in 2008, prompting widespread concerns about food availability and starvation (particularly in developing countries), that governments and investors faced a popular backlash.

Reports published by the United Nations’ Food and Agriculture Organization and other international agencies concluded that, at best, biofuels would only offset a moderate share of fossil fuel consumption over the next decade and that their costs-in terms of deforestation, resource use and displaced food production-often outstripped their purported benefits.

Scientists have also warned that the health and environmental costs could be significant. A study published in the journal Proceedings of the National Academy of Sciences found that increased corn ethanol production would worsen the Gulf of Mexico “dead zone,” an area practically devoid of life that is the size of New Jersey. A more recent study published in the same journal found that the combined climate change and health costs associated with first generation ethanol production and combustion could greatly exceed those of gasoline if large tracts of agricultural land are displaced as a result-though, on the positive side, it did also find that cellulosic ethanol production from sustainable sources (prairie biomass, corn stover, or switchgrass) would drastically lower emission costs.

The primary objection raised against biofuel production is that it could cause widespread deforestation in tropical countries such as Indonesia, Brazil, and Malaysia. Holly Gibbs, a postdoctoral researcher at Stanford University, cautioned at a recent scientific meeting that policies that favored biofuel crop production could worsen climate change by accelerating the destruction of rainforests. Brazil and Indonesia, which have two of the world’s most coveted first-generation biofuel crops (soybean and palm oil, respectively), have experienced a boom in production that has resulted in the conversion of large tracts of once lush rainforests into mono-crop farmlands. In Indonesia, palm oil production tripled during the 1990s and doubled again between 2000 and 2007.

According to Gibbs, the destruction of rainforests results in the release of more greenhouse gas emissions than are conserved through the use of current-generation biofuels, creating what is called a “carbon debt.” Because rainforests are some of the planet’s largest carbon reservoirs, storing over 340 billion tons in the aggregate, recouping the losses incurred by deforestation could take several centuries to millennia.

While doubts still abound about the future of biofuels, many scientists and environmentalists believe that an emphasis on sustainability can provide a viable path forward for biofuel production. An article co-authored by 23 scientists in the journal Science last year laid out several guiding principles for industry and legislators, advising them to consider both the environmental and politicoeconomic consequences of biofuel production and urging a rapid shift to cellulosic ethanol production.

Existing policies are inadequate, they warn, and risk altering the landscape of the planet for the worse if nothing changes. Embracing sustainability as a way of life need not mean banishing biofuels; it simply means revamping our current approach so that we recognize the national and international implications of our actions.

“Sustainable biofuel production systems could play a highly positive role in mitigating climate change, enhancing environmental quality, and strengthening the global economy, but it will take sound, science-based policy and additional research effort to make this so,” the authors conclude. In selecting Dr. Steven Chu, the former director of the Lawrence Livermore National Laboratory, to head up the Department of Energy, President Obama has given the sustainable biofuel movement a shot in the arm and made clear his intention to invest considerable resources into a robust renewable energy research agenda. By taking these recommendations to heart, Mr. Obama can begin to lay the groundwork for an enduring energy infrastructure that will far outlive his presidency.

Jeremy Jacquot is a graduate student in marine environmental biology at the University of Southern California and is a contributing writer for DeSmogBlog, Discover Magazine, and Popular Mechanics.

Most experts now agree that the estimates made by the Intergovernmental Panel on Climate Change in 2007, which predicted that a sea level rise between 7 inches and 2 feet by 2100, were much too conservative because they did not take the contributions from rapidly melting glaciers and ice sheets into account. Ocean thermal expansion, which occurs when oceans grow in volume when they absorb more heat, was once considered the driving factor behind sea level rise. But new melt rate data collected from Greenland and Antarctica in recent years now suggests that deglaciation is a more significant factor. A landmark study published in 2005 made the threat starkly clear, as it found that the complete melting of the Greenland and Antarctic ice sheets could raise sea levels by about 70 meters.

By some estimates, a 3-foot rise could still be too optimistic.

Here in the United States, a joint report co-authored by the Environmental Protection Agency, the National Oceanic and Atmospheric Administration, the US Geological Survey, and the Department of Transportation unveiled this past week concluded that Florida, Louisiana, North Carolina, and Texas were the most susceptible states. The report, entitled “Coastal Sensitivity to Sea Level Rise: A Focus on the Mid-Atlantic Region,” warned that coastal erosion will quicken as sea levels rise, causing the sandy shores that make up the region’s coast to slowly crumble and put millions at risk. Because some parts of its coast are already sinking, North Carolina would be especially hard-hit. Under the report’s worst-case scenario, sea levels could rise by as much as 3 feet by century’s end, which would result in some of the Mid-Atlantic’s barrier islands “crossing a threshold” and collapsing.

By some estimates, a 3-foot rise could still be too optimistic. According to a study published earlier this month in the journal Climate Dynamics, sea levels could rise between 0.9 and 1.3 meters by 2100—or roughly three times higher than what the IPCC forecasts. To predict what would happen in the future, the authors, an international team of researchers from Denmark, England, and Finland, looked to the past—specifically at the connection between average global temperatures and the sea level two millennia ago. They discovered a direct relationship between the two: warm episodes were often marked by periods of sea level rise, while cool periods, like the “little ice age” that took place during the 18^th century, were marked by periods of sea level decline.

If this relationship still applies today, and global temperatures rise by about 3 degrees by century’s end (if not more), as is widely expected, the authors conclude that the seas could rise over a meter, which would have disastrous consequences for many parts of the world. For this to happen, ice sheets and glaciers would have to melt at a much faster rate than most scientists have been forecasting—something that many, in the face of gloomy 2007 and 2008 melt rate measurements, now believe could be the new normal. Indeed, according to Wilfried Haeberli, the director of the World Glacier Monitoring Service, glaciers are melting so fast that most could be gone by the middle of the century.

While the United States and other developed countries will eventually be forced to adapt to the impacts of rising sea levels, poor nations, which largely lack the resources to do so, will be in for a world of hurt if present trends continue. A World Bank report published last year in the journal Climatic Change determined that tens of millions of people in 84 coastal developing countries will likely be displaced by rising sea level over this century alone. As Science Progress noted last week, the country that could suffer the most devastating losses is Vietnam.

According to the report, a one-meter sea level rise could displace over a tenth of the country’s population—roughly 8.6 million people—which lives in low-lying areas and along the coast. Mauritania, Guyana, Jamaica, and the Bahamas—the latter of which could lose over a tenth of its land to sea level rise—would be some of the other hardest-hit countries. Overall, a one-meter rise would affect about 56 million people spread over 194,000 square kilometers. An earlier report commissioned by the IPCC identified the South Pacific, including the island nations of Kiribati and Tuvalu, as ground zero for sea level rise; the 7 million Pacific Islanders, most of whom live within 1.5 kilometers of the shore, could join the growing numbers of early climate refugees.

To help these countries avoid the worst, the developed world should begin to disburse aid according to the degree of threat, the authors conclude, and help their governments develop national adaptation plans. Which is easier said than done, of course. Even most developed countries are struggling to come up with strategies to forestall future losses caused by erosion, agricultural degradation, and coastal flooding. According to the U.S. Climate Science Program report, most current mitigation policies—rebuilding at the same location, relocating, coastal engineering, or some combination thereof—would fail to hold back the faster sea level rises that are now widely predicted. Existing structures are designed for current sea level and do not take into account the effects of coastal erosion. Better land-use planning, retrofitting, and science-based management are all necessary to prevent the worst from happening.

Jeremy Jacquot is a graduate student in marine environmental biology at the University of Southern California and is a contributing writer for The Huffington Post, Discover Magazine, DeSmogBlog, and TreeHugger.

Having spent the last few decades piecing together the different components of the global carbon puzzle, scientists now have a good idea of how the planet’s natural carbon sinks (or reservoirs) work—primarily these sinks are plants and the oceans. But when it comes to pinpointing the locations of all the sources (areas or organisms which release carbon dioxide to the atmosphere), there remains a lot of ambiguity—mostly because climate change is constantly changing the picture of how the sources work (and it’s usually changing for the worse). Indeed, scientists are only beginning to understand how the behavior of sinks and sources will shift as atmospheric CO₂ levels continue to increase. And they do not like what they see. What many scientists are now worried about is the degree to which carbon sinks could shrink, or carbon sources could grow, in response to the rapid increase in anthropogenic CO2 emissions.

The easiest way to think of the global carbon cycle is as the sum total of different reactions—primarily those resulting in the destruction or formation of calcium carbonate or organic matter like carbohydrates—between and within the planet’s major carbon repositories: the ocean and terrestrial biosphere.^[1] The ocean is by far the larger one—estimated to hold about 38,000 petagrams (1 petagram equals one trillion grams); the land plants and soils that make up the terrestrial biosphere store only about 2,000 Pg.^[2]

Scientists are beginning to come to grips with the realization that many erstwhile sinks, primarily plants and soils, could lose their ability to draw down CO2 in a warming world.

Carbon transport between and among the reservoirs is primarily accomplished via CO₂ gas exchange. The two types of processes that affect the flow of the global carbon cycle are “long-term” fluxes—those that operate on the scale of millennia (anything having to do with weathering, or the decomposition of rocks, minerals, and soils)—and “short-term” fluxes—which are driven by natural reactions like photosynthesis and respiration (when plants absorb carbon dioxide directly from the atmosphere, for instance). These help control the concentration of CO₂ in the atmosphere.

Together, the ocean and land absorb roughly 2.1 petagrams of carbon every year; that number is the difference between the average amount of fossil fuel emissions produced, about 5.4 Pg of carbon per year, and the growth in atmospheric CO₂ concentrations, around 3.3 Pg per year. These numbers are based on measurements taken during the 1980s, one of the most recent decades for which researchers have an estimate of all sources and sinks.

So how do scientists distinguish between the contributions made by each sink? Until the mid-1990s, that question was still very much in doubt. Though researchers knew about the major sinks and sources, they were unsure as to the magnitude of the terrestrial sources—particularly the one associated with tropical deforestation (which, for a long time, they thought accounted for 10 and 50 percent of all fossil fuel emissions). Their calculations seemed to suggest that there was an additional “missing” sink somewhere, but they couldn’t put their finger on it.

In a landmark study published in 1996, Ralph F. Keeling of the Scripps Institution of Oceanography (the son of Charles D. Keeling, the man behind the famous “Keeling Curve”) and colleagues showed that it was possible to determine the difference between the two sinks by examining the partial pressures—what scientists describe as the pressure exerted by each of the constituents of a mixture of gases—of CO₂ and O₂ in the atmosphere.^[3]

Scientists already knew that an increase in atmospheric CO2 corresponded to an equivalent decrease in atmospheric O2 (because of photosynthesis and respiration). Keeling’s breakthrough was demonstrating that the ocean, though a crucial sink (and source) for CO2, did not release much O2 in response to a decrease in atmospheric O2. This meant that any change in atmospheric O2, other than that resulting from fossil fuel use, had to be attributed to a terrestrial source. Working backwards, they were able to quantify the importance of the different sources and sinks.

As most climate scientists will tell you, though, there is always a large degree of uncertainty implicit in these measurements so they could, in reality, be very different. Moreover, because the carbon balance—the difference between the amount of emissions released to the atmosphere and those taken up by sinks—is never static, year-to-year variations can be significant. These can usually be attributed to fluctuations in the response of the terrestrial biosphere to the climate—often because of increased land-use or changing water availability. The oceanic response, by comparison, is typically muted.

These sinks currently absorb around half of all the carbon dioxide emitted through fossil fuel combustion.^[4] Around 85 percent of new anthropogenic CO2 ends up in the ocean, where, after slowly dissolving into the surface waters, it gets trapped in the “conveyor belt” (also known as thermohaline circulation), the large-scale movement of currents driven by density gradients in the deep. Almost half of the total amount of anthropogenic CO2 that has been added to the atmosphere since pre-industrial times has gone into the ocean.^[5]

Indeed, as I wrote about in a recent column, scientists are beginning to come to grips with the realization that many erstwhile sinks, primarily plants and soils, could lose their ability to draw down CO2 in a warming world—with a worst-case scenario being that they would turn into sources.

Steven W. Running of the University of Montana at Missoula’s College of Forestry crunched the numbers in an article for Science a few months ago and was dismayed by the results.^[6] Though several of the 11 land models he ran projected that photosynthesis rates would dramatically increase under conditions of doubled atmospheric CO2 levels, he found that most did not incorporate land-use variations or episodic disturbances like wildfires and insect epidemics.

Those are crucial omissions, he says, since a recent FLUXNET synthesis determined that disturbances often caused sinks to turn into sources. (FLUXNET is a global network of micrometeorological tower sites which measure the exchanges of CO2, water vapor, and energy between the terrestrial biosphere and the atmosphere.) With droughts, wildfires and insect invasions, such as the mountain pine beetle epidemic, on the rise, Running cautions that many important terrestrial sinks could soon become sources.

The ocean, of course, faces its own litany of problems. As I’ve written about in the past, ocean acidification is a major concern—and one that has only become more acute in recent months. A study published last week in the Proceedings of the National Academy of Sciences found that increases in acidity are happening over 10 times faster than previously thought. This is a major problem, as lead author Timothy Wootton of the University of Chicago’s Department of Ecology and Evolution explains, because, as the ocean’s natural carbonate buffering system weakens—the direct result of millions of tons of CO2 lowering the pH of seawater—it will no longer be able to absorb as much atmospheric CO2. And that could spell big trouble for all of us.

One tool that promises to make scientists’ work much easier in the near future is NASA’s Orbiting Carbon Observatory, a satellite that will track the geographic distribution of atmospheric CO2—and thus help pinpoint the exact locations of all the sinks and sources. While not a solution in of itself, the OCO will help researchers refine their models, making them more useful for policymakers, which, in turn, should lead to the creation of more effective, targeted mitigation strategies.

Jeremy Jacquot is a graduate student in marine environmental biology at the University of Southern California and is a contributing writer for The Huffington Post, Discover Magazine, DeSmogBlog, and TreeHugger.

Notes

^[1] Sarmiento, J. L. & Gruber, N. (2002). Sinks for Anthropogenic Carbon. Physics Today, 30 – 36.

^[2] Emerson, S. R. & Hedges, J. I. (2008). Chemical Oceanography and the Marine Carbon Cycle. Cambridge University Press: New York, NY.

^[3] Keeling, R. F., Piper, S. C. & Heimann, M. (1996). Global and hemispheric CO₂ sinks deduced from changes in atmospheric O₂ concentration. Nature, 381, 218 – 221.

^[4] Schimel, D. S. et al. (2001). Recent patterns and mechanisms of carbon exchange by terrestrial ecosystems. Nature, 414, 169 – 172.

^[5] Emerson, S. R. & Hedges, J. I. (2008). Chemical Oceanography and the Marine Carbon Cycle. Cambridge University Press: New York, NY.

^[6] Running, S. W. (2008). Ecosystem Disturbance, Carbon and Climate. Science, 321, 652 – 653.

If we’ve learned anything from the financial crisis (and I certainly hope we have), it is that the priorities of Wall Street still largely dictate the priorities of our governments. Who would have ever thought that one of the most gung-ho, pro-market administrations in recent history would bail out several investment firms and—gasp—nationalize (at least partly) others? Yet, at the same time that some governments are frantically shoring up their faltering financial markets by shoveling in billions of dollars, they also are preparing deep cuts in spending for less “essential” sectors. One of those likely to be affected in the short-term is government science. That’s why now is the time for scientists to stand up, speak up, and practice communicating to policymakers the reasons why science helps Americans live safer, healthier, and more productive lives.

One reason why scientists rarely, if ever, get a seat at the table in Washington D.C. is that the profession lacks charismatic, influential leaders (and, no, Al Gore does not count).

Although President-elect Barack Obama promises to boost research funding during his first term in office, and pledged to double the budget of the National Institute of Health over the next decade, one can expect to see some degree of retrenchment. Unfortunately, this could mean science budgets will stagnate further or remain at the lows imposed by the previous administration. According to the National Science Foundation, federal research funding fell for 2 years running in real terms between 2006 and 2007 for the first time in its 35-year record-keeping history.

To say that further cuts would come at the worst possible time is no small exaggeration. The Obama administration will need to deal with a number of pressing science-related issues, such as managing the threat of bioterrorism and the budding nanotechnology market—and that’s not even including tackling the looming climate crisis. Science may have been persona non grata on the campaign trail (despite the best efforts of the Science Debate 2008 team), with climate change only making token appearances in several debates, but it can longer fly under the radar. Indeed, as Science Progress contributing editor Chris Mooney pointed out earlier this week, Obama made it clear in his Tuesday night speech that science is as pivotal to our future as it has been to our past, saying of the 20^th century: “A man touched down on the moon, a wall came down in Berlin, a world was connected by our own science and imagination.”

But already we have seen several prominent research labs close up shop under the strain of funding difficulties, and we will likely see many more in the coming months as the credit crunch’s tentacles continue to spread. With many universities set to pare back their hires over the coming years, an already poor job market for new science graduates in academia could become bleak.

So what should be done? For one thing, those who value science and the innumerable contributions it has made to society should continue make the case to their elected representatives that we need policies that maintain and expand research funding. In an ideal world, your average news consumer would be familiar enough with the latest science so as to appreciate the challenges we face and the need for more federal support. (A man can dream, can’t he?)

On a more fundamental level, what we need right now is not necessarily more scientists (though that certainly wouldn’t hurt), but more effective science communicators. One reason why scientists rarely, if ever, get a seat at the table in Washington D.C. is that the profession lacks charismatic, influential leaders (and, no, Al Gore does not count). In an arena dominated by lawyers, former bankers, and military officers, rare is the legislator who hails from a background in research or academia—with a few notable exceptions.

As much as scientists like to disavow it, there is much truth to the well-worn stereotype of the scientist as a reclusive nerd. When scientists do congregate en masse, they tend to split off by discipline—the chemists stay with the chemists and the biologists stay with the biologists. Moreover, the scientific community, though close-knit, is very insular: researchers often have little patience for journalists or the average layman when it comes to communicating their work. “If only they knew what I knew,” they say, “then they would understand why my research is so important.”

Unfortunately that is not necessarily the best way to get your point across to an uninformed public—or to ingratiate yourself to a skeptical but powerful politician, for that matter. In their landmark article on the subject, called “Framing Science,” Matthew C. Nisbet, a professor of communication at American University, and Chris Mooney argue that scientists must learn to actively “frame” their research to make it relevant to a variety of audiences. Because regular citizens are often unable to weigh competing theories and arguments, they say, scientists need to pare down complex issues, or “frame” them, in order to help the average news reader understand why it matters and, if action is necessary, what should be done.

While many scientists remain resistant to the idea, suggesting that science should always be kept separate from the political process, several organizations have stepped into the void to provide media training and policy fellowships to the younger generation of scientists.

Communication Partnership for Science and the Sea, or COMPASS, organizes training sessions on campuses around the country to help faculty and graduate students in the marine sciences communicate information to the public, the media and policymakers. National fellowship programs such as the American Association for the Advancement of Science’s prestigious Science & Technology Policy Fellowship place freshly-minted Ph.D.s in government agencies—everything from the FBI to the USDA—to help them learn the ropes of the legislative process. Organizations like the Union of Concerned Scientists and Research!America are vocal advocates for research and help to bring important science issues to the fore of policy conversations.

We will need as many effective communicators as we can muster if we hope to successfully confront the scientific challenges of the 21^st century, and now is the moment to speak up and be heard.

Jeremy Jacquot is a graduate student in marine environmental biology at the University of Southern California and is a contributing writer for VentureBeat, DeSmogBlog, The Huffington Post, and TreeHugger.

Come again?

Their logic goes something like this: Because plants require carbon dioxide to do photosynthesis, wouldn’t it make more sense to allow atmospheric levels to further increase beyond their long-term average—rather than reduce them—so as to make more available for the planet’s flora, thus ensuring a lush supply of greenery? In other words, pump more carbon dioxide into the atmosphere and, ipso facto, you’ll have more plants doing more photosynthesis—naturally taking care of any pesky (supposed) warming problem that might arise. Or so skeptics and their allies in the energy industry would have you believe.

Ecosystems are already struggling to keep up with the meteoric growth in emissions over the past few decades.

I have to admit that, to a certain audience, that logic must have a distinct appeal. It effectively removes much of the burden of emission regulation from our shoulders and places it squarely on those of the planet’s ecosystems. While it does not necessarily give us carte blanche to continue emitting at an unabated rate, it seemingly provides some measure of relief: the knowledge that Mother Earth will take matters into her own hands should we fail to do so ourselves. If only that was the case. Thanks to evidence from several recent studies, scientists now know that, far from helping ecosystems, higher emission levels could actually harm their short- and long-term ability to take up and store carbon dioxide—producing, in effect, a so-called climate “double whammy.” That is, as emissions rise due to human activity, some plants will naturally absorb less of that CO2, which will in turn further accelerate atmospheric concentrates because those very same plants will no longer be able to move the greenhouse gas from the air to the soil.

Because plants and soils act as major carbon sinks, any reduction in their ability to draw down and store CO2 could have dramatic consequences for the climate. As things stand, ecosystems are already struggling to keep up with the meteoric growth in emissions over the past few decades; placing any further undue stress would only make matters worse—and, at the same time, make our efforts to fight climate change that much harder. A warmer world in which plants, one of our first-line defenses against rising CO2 levels, become impotent would force us to drastically revise our current emission scenarios and make it much more difficult for us to mount an effective response in time. A study published in a recent issue of Nature suggests that we may be approaching this dangerous tipping point.

A large team of researchers, led by Jay Arnone of the Desert Research Institute, organized a four-year study to track the response in CO2 uptake and loss in ecosystems during abnormally warm years.^[1] To do so, they sealed large plots of native Oklahoma tall grasses inside simulated environment chambers in which they were able to replicate daily and seasonal temperature and rainfall changes. After letting the plots condition for the first year, the scientists exposed half of them to a range of temperatures typical of a regular year and exposed the other half to temperatures on average 4°C higher (in line with the predictions made by the United Nations’ Intergovernmental Panel on Climate Change). These anomalously high temperatures were turned down during the third year to match those in the control plots.

Arnone and his colleagues found that the plots exposed to the higher temperatures experienced a net reduction in CO2 uptake for at least two years; furthermore, they only captured and stored about one third as much carbon during those two years as did the control plots. They attributed this to two main causes: a suppression of net primary productivity, which refers to the amount of CO2 absorbed by a plant during photosynthesis minus the CO2 it emits during respiration (the process by which plants break down sugars into useable energy) induced by the drought-like conditions and higher respiration rates by the soil’s microorganisms during the second year. The authors conclude that, “more frequent anomalously warm years, a possible consequence of increasing anthropogenic carbon dioxide levels, may lead to a sustained decrease in carbon dioxide uptake by terrestrial ecosystems.”

These grim findings echoed the results of an earlier study done this year in which a team of scientists investigated the ability of northern ecosystems to store carbon in response to autumnal warming.^[2] Using data from past atmospheric records to examine year-to-year variations in atmospheric CO2 concentrations and ecosystem CO2 fluxes, they found a trend over the last two decades that pointed to an earlier autumn-to-winter build-up, suggesting a much shorter net carbon uptake period. They then combined this data with observations gathered from a terrestrial biosphere model and satellite imaging to further study the ecosystems’ response to autumnal warming, which revealed that both photosynthesis and respiration increased during that period—though respiration did so at a faster rate. In other words, the plants were emitting more CO2 than they were storing—resulting in a net release of CO2 to the atmosphere.

Shilong Piao, the lead author, and his colleagues conclude that the loss in carbon uptake during this period could offset as much as 90 percent of the increased carbon uptake witnessed during spring warming. This means that if future autumnal warming continues to outpace spring warming, the ability of northern ecosystems to take in and store CO2 could be sharply curtailed much sooner than previously expected.

Now, granted, we may still be a ways off before global temperatures rise another 4°C (though we’ve already seen some isolated incidents). And, admittedly, much more work needs to be done in more locations before we can truly accept these findings as fact. Indeed, a study done in 2001 suggested that grasslands could act as potent carbon sinks under conditions of elevated atmospheric CO2 levels because higher levels would inhibit microbial respiration—at least for the short term.^[3]

Yet, as with much environmental science, what really matters here are the general trends—and these mostly point to a warmer climate in which ecosystem carbon uptake will be significantly reduced. For an indication of what may be to come, it helps to look at a recent real-life example: the European heat wave of 2003. That year, temperatures during the summer surged above their long-term means—July temperatures alone were up to 6°C higher—resulting in tens of thousands of deaths. Scientists who studied the impact of the continent-wide drought on primary productivity discovered that it caused a significant drop in CO2 uptake and reversed the effect of four years of net carbon sequestration.^[4] Of particular note was their conclusion that future drought events could turn Europe’s temperate ecosystems into carbon sources—not sinks—thus contributing to the onset of intense climate change. Could the same happen in southwestern states such as California and Arizona, which have been battered by a wave of severe droughts in recent years? Only time will tell of, course—there are many factors at play—though I can’t say the European example fills me with much confidence.

In the end, what all of this tells us is that we can’t take it for granted that plants will always be there to bail us out. Though they will remain a major carbon sink for the foreseeable future, we may not have the luxury of relying on them as much if we don’t start taking responsibility for our actions soon.

Jeremy Jacquot is a graduate student in marine environmental biology at the University of Southern California and is a contributing writer for VentureBeat, DeSmogBlog, and TreeHugger.

Notes

[1] Arnone, J.A. et al. Prolonged suppression of ecosystem carbon uptake after an anomalously warm year. Nature, 455 (2008): 383—385.

[2] Piao, S. et al. Net carbon dioxide losses of northern ecosystems in response to autumn warming. Nature, 451 (2008): 49—54.

[3] Hu, S. et al. Nitrogen limitation of microbial decomposition in a grassland under elevated CO2. Nature, 409 (2001): 188—191.

[4] Ciais, Ph. et al. Europe-wide reduction in primary productivity caused by the heat and drought in 2003. Nature, 437 (2008): 529—533.

As a climate modeler, you are always working with the best of what’s available—whether that means the best data, best infrastructure, or best science.

To be fair, “denigrate” might be a little too strong of a word to use to characterize the often-legitimate criticism that has come climate modeling’s way. The critics’ main point of contention? Quite simply that models cannot—and likely never will—accurately represent the whole climate picture. There are simply too many known unknowns and unknown unknowns—pardon the reference—for even the most skilled modeler to wrap his head around. On a more basic level, does anybody really think that a collection of models, let alone a single model, can fully reproduce Earth’s complex inner workings? No, of course not, and that’s a point any climate modeler will readily concede.

As a climate modeler, you are always working with the best of what’s available—whether that means the best data, best infrastructure, or best science. And since all those variables are subject to frequent revision, it’s rare to find a robust model that is able to withstand years of new findings. Scientists often relish poking holes in them, using the results from a recent research expedition, for instance, to undermine a single component—regardless of how well the model otherwise captures the environment. While some of this criticism may seem gratuitous, or even childish at times, it is often done with good reason.

Take a recent study published in the Proceedings of the National Academy of Sciences, whose findings risk invalidating over 60 percent of the so-called “climate envelope” studies. Climate envelope models help predict where species will live under conditions of future climate change by using their current distributions to make up a set of climatic conditions—the “envelope”—that closely approximate their needs.

In the past, these models have come under withering criticism for failing to take into account a number of other factors, such as anthropogenic activity or species-species interactions, that figure as prominently, if not more so, as climate change in influencing species distribution. Despite some of their limitations, the Intergovernmental Panel on Climate Change put its stamp of approval on their use in its 2007 report, noting that they “offer the advantage of assessing climate change impacts on biodiversity quantitatively.” Colin Beale of the United Kingdom’s Macaulay Institute of Land Use Research, the PNAS study’s lead author, found that the models performed no better than a simple roll of the die—pure chance—in approximating several bird species’ natural habitats.

To be clear, Beale’s study would not be the first to take such a dismissive view of climate envelope studies—many scientists argue that they still play an important role in predicting future species abundances, if not their exact distributions—and should therefore be taken with a grain of salt. In other words, the pretext of the study is not to invalidate the findings of the IPCC or to cast doubt on the link between climate change and species. Beale is quick to point out that his study did find a significant relationship between the climate and a third of species—and that he is concerned his findings could be misused as evidence that there is no link between climate change and species extinctions.

Other scientists have been critical of the IPCC for seemingly lending too much credence to models’ predictive abilities. While several existing models, especially the so-called “coupled” models (which consider the atmosphere, oceans, land surface, sea ice, and other physical characteristics in conjunction to project future climate trends), have become advanced enough to yield valuable insights on current and past climate patterns—almost matching the accuracy of conventional atmospheric observations—most fall woefully short when it comes to answering the most important question: What will our future climate look like?

One big problem, some argue, is that many current models suffer from oft-debilitating inconsistencies—in their representations of observed changes in global mean surface temperature or in their range of sensitivities, for example—that could significantly diminish their capability to reduce uncertainties in Earth’s climate dynamics and, thus, to predict future changes. As a result, they suggest that international organizations like the IPCC, which have a lot of clout in the scientific and political communities, tamp down some of their expectations—lest they invest too much credibility in models that could very well turn out to be wrong.

If there’s one issue on which most scientists—modelers included—agree, it’s that climate modelers need more: more research funding, more powerful computers to run their “petascale” models (which can make a whopping 1,000,000,000,000,000 calculations per second), and more time to meet ever-rising expectations. With the IPCC shifting its focus to examining the community and state-level impacts of various climate change scenarios (so as to impart more actionable information for policymakers) for its 2013 report, the pressure is on climate modelers to redouble their efforts to come up with more powerful and accurate global models. The bottom line is that we should by no means abandon modeling, but do need to help improve it.

Already premier research institutions like the Breckenridge, Colorado-based National Center for Atmospheric Research, the originator of one of the most widely used coupled models in the United States, is falling behind on meeting an October 1 deadline to update it. Even legislators who tend to only focus on the short-term—in other words, most of them—should see the wisdom in supporting work that could also lead to better hurricane research, an outcome that would yield immediate, and very tangible, benefits.

Perhaps Science Progress contributing editor Chris Mooney put it best in framing his argument for more research funding by tying together hurricanes, climate change and what he calls the “next” New Orleans:

“Which inevitably brings us to contemplating the future—one in which we will be even more exposed to hurricane risks. While it remains hard to predict precisely what global warming will do to hurricanes, we know that it will raise sea levels, and probably intensify storms on average, not to mention increasing their rainfall rates. No matter how you slice it, then, global warming worsens hurricanes—and, accordingly, hurricane-related insurance costs—which makes it a more-than-legitimate topic to invoke in the context of this year’s hurricane threats and landfalls.”

The impacts of climate change are predictable, but the task will be difficult without the additional resources to build more accurate models and adapt to an altered planet.

Jeremy Jacquot is a graduate student in marine environmental biology at the University of Southern California and is a contributing writer for VentureBeat, DeSmogBlog and TreeHugger.

Save for some new findings and spirited debate among the scientific community, the sulfurous gas, which some believe could play a vital role in mitigating climate change, has been overshadowed by its more infamous colleague, carbon dioxide. With efforts to slow the rapid accumulation of greenhouse gases at a virtual standstill in many parts of the world and clean energy technologies in their early stages of deployment, some scientists are optimistic about Earth’s ability to regulate its climate through the production of DMS and other natural processes. But before DMS becomes the next darling of geoengineering proponents, it’s worth understanding both this chemical’s place in the marine ecosystem and the point that the planet cannot fix the manmade problem of global climate change. Moreover, the planet cannot fix itself while humans continue to generate greenhouse gases unabated.

Relying solely on nature to rectify man’s mistakes will not be sufficient.

James Lovelock first articulated the DMS-climate link in the early 1970s. Lovelock is a renowned scientist and the originator of the Gaia hypothesis—which holds that the planet is a single large organism that self-regulates in order to maintain optimal conditions.^[1] Though Lovelock and his colleagues theorized that DMS, which is produced by phytoplankton, provided the missing link to explain the elevated levels of sulfate aerosols emissions above the sea surface, they initially lacked the appropriate mechanism to account for it.^[2]

Upon being excreted by phytoplankton, some fraction of DMS finds its way into the atmosphere, where, through oxidation, it forms sulfate aerosols, while the remainder is broken down by microbial activity in the water column. At a loss to explain how these aerosols helped moderate the climate, Lovelock turned to Robert Charlson, a chemist at the University of Washington, who suggested that they formed cloud condensation nuclei, or CCN—small particles that act as centers for the condensation of water to form cloud droplets. A higher concentration of cloud droplets would increase the reflectivity of marine clouds, blocking a portion of solar radiation and causing a slight cooling of the atmosphere. The presence of clouds over the oceans, which cover roughly 70 percent of the planet’s surface area, is more important climatically because they absorb a majority of the sun’s heat.

Charlson’s hypothesis was bolstered by satellite images that showed cloud plumes intensifying due to the addition of smoke particles from ships. Scientists already knew that marine clouds could become brighter, and therefore more reflective, if they had more particles. This breakthrough led to the publication of a seminal paper in which Lovelock, Charlson, and two colleagues proposed that DMS may have helped cool the Earth during past periods of high solar radiation or increasing greenhouse gases—serving, in effect, as the planet’s thermostat.^[3]

Now, with greenhouse gases once again on the rise, some scientists believe DMS production could pick up, providing a natural check on climate change. How effective a check it proves to be, especially in light of the pace at which we are consuming fossil fuels, remains to be seen; specifics about how much DMS is presently in the atmosphere and how quickly it moves there are still poorly understood. Some believe DMSP, or dimethylsulfoniopropionate—the precursor of DMS—is used by phytoplankton to regulate the salinity and temperature within their cells or to repel predators; others think phytoplankton convert DMSP to DMS in response to stress from UV radiation—the sulfur compound helps remove reactive molecules that cause damage from their cells.

Lovelock and Chris Rapley, the director of London’s Science Museum, recently put forth a scheme that would harness the phytoplankton’s increased productivity by installing large arrays of vertical pipes that would mix nutrient-rich deep water with surface waters. This, they argue, would cause more blooms and, in turn, speed up the production of DMS—essentially hitting two geoengineering birds with one stone. They are currently advising Atmocean, a startup that is developing such a technology. Supporters of ocean iron fertilization, a scheme in which iron sulfate particles are dumped into the ocean to stimulate blooms, have also latched onto this idea.

But as I’ve written about previously on Science Progress, such ecological tinkering could be the cure that is worse than the disease. While these proposals to assist natural temperature regulation could eventually show promise, many researchers believe it is still too early to tell whether natural processes alone can put a damper on climate change. Reducing the amount of heat reaching the oceans could change wind patterns or decrease surface water mixing, potentially cutting down the amount of nutrients available for phytoplankton to grow. And reducing the amount of sunlight reaching the planet could slash global precipitation levels, possibly leading to more droughts. Moreover, 200 countries at the U.N.’s Convention on Biological Diversity, citing the unknown risks, voted in May for a moratorium on projects that aim to spur algae growth in the oceans. Finally, these geoengineering proposals won’t stop other impacts of increased carbon in the atmosphere, like ocean acidification.

Because scientists still do not fully understand the DMS cycle, they are worried that they could be missing out on an important intermediary or process—which could throw a wrench into their predictions. In the end, relying solely on nature to rectify man’s mistakes will not be sufficient; while the planet has a role to play, it is simply too risky to hope Mother Earth, even with a little extra push, will clean up after our actions. Reducing our greenhouse gas emissions is the only guaranteed way to fix the problem.

Jeremy Jacquot is a graduate student in marine environmental biology at the University of Southern California and is a contributing writer for VentureBeat, DeSmogBlog and TreeHugger.

Notes

[1] J. Lovelock, Gaia: A New Look at Life on Earth (Oxford University Press, USA, 2000).

[2] R. A. Kerr, “No Longer Willful, Gaia Becomes Respectable,” Science, 240(1998): 393–395.

[3] R. J. Charlson, J. E. Lovelock, M. O. Andreae & S. G.Warren, “Oceanic phytoplankton, atmospheric sulphur, cloud albedo and climate,” Nature, 326 (16) (1987): 655 – 661.

Around 90 percent of the ocean’s largest fisheries species have now been extinguished, and live coral cover has been reduced by up to 93 percent on some reefs.

It’s time to face up to the facts: If we continue to ignore the terrible plight befalling our oceans for much longer, we risk losing what makes them such a unique and valuable natural resource: their rich biodiversity. With most large fisheries stocks now in decline, and with what is left over besieged on all fronts by global warming, ocean acidification, pollution and habitat destruction, it is only a matter of time before our fragile ocean ecosystems complete the long and painful transition from lush, species-rich habitats to barren deserts. But don’t take it just from me. Jeremy Jackson of the Scripps Institution of Oceanography, one of the world’s preeminent experts on the impacts of human activities on the ocean, has written what can only be described as a disturbing diagnosis of our ocean’s health. In his article, published in the Proceedings of the National Academy of Sciences, Jackson warns that the ocean stands on the brink of a mass extinction—one that could just as easily be precipitated by our actions as by the impacts of climate change. Taken together, these problems risk “transforming once complex ecosystems like coral reefs and kelp forests into monotonous level bottoms, transforming clear and productive coastal seas into anoxic dead zones, and transforming complex food webs topped by big animals into simplified, microbially dominated ecosystems with boom and bust cycles of toxic dinoflagellate blooms, jellyfish, and disease,” Jackson writes.

As fatalistic as this may sound, Jackson’s prognosis is given all the more weight because many of the earlier predictions he made a decade ago—though greeted with snorts of derision and loud skepticism at the time—have largely been vindicated. Around 90 percent of the ocean’s largest fisheries species have now been extinguished, and live coral cover has been reduced by up to 93 percent on some reefs. Record amounts of agricultural runoff, fuelled by poor farming practices and our overreliance on industrial fertilizers, are choking our oceans—sparking mass toxic algal blooms and turning once vibrant ecosystems into lifeless dead zones. Sea-surface warming, by increasing the stratification of the oceans (preventing the mixing of deep, nutrient-rich waters with shallow, depleted waters), has caused the ocean’s least biologically productive areas—the so-called ocean “deserts”—to expand much faster than originally predicted, putting the populations of many fish species at risk of extinction. And, if we are to believe his most gloomy prognostications, the worse has yet to come: a future in which the “mass extinction of multicellular life will result in profound loss of animal and plant biodiversity” and lead to the rise of “slime” (what he calls microbes).

The best way to ensure the successful restoration of threatened habitats, the authors explain, is to devolve more authority to local communities, which are naturally more invested in them.

Yet, despite the severity of the situation, not all is lost. In addition to dispensing the usual set of solutions—reducing greenhouse gas emissions, improving ocean and coastal management policies and establishing more marine protected areas, or MPAs—Jackson also suggests switching from wild fisheries, which he claims will not be able to sustain growing global demand (regardless of how well they are managed), to a sustainable form of industrial aquaculture. With the right environmental standards in place, and the requisite political will, he argues that aquaculture will be compatible with a policy approach focused on habitat preservation and pollution mitigation. Another interesting idea would be to eliminate the subsidies that have sustained the excessive consumption of chemical fertilizers and pesticides and to tax their use. This would help greatly reduce the number of hypoxia and eutrophication events that have contributed to the formation of over 400 dead zones—affecting an area of more than 245,000 square kilometers (roughly the size of Oregon)—worldwide.

In another article recently published in PNAS, Stanford University ecologists Paul Ehrlich and Robert Pringle prescribe a series of simple, commonsense solutions, which they whimsically call “a hopeful portfolio of partial solutions,” that, while not specifically targeted at the oceans, could easily be applied to just about any ecosystem. Encouraging ecotourism and placing an accurate value on the services ecosystems provide—such as natural water filtration, flood mitigation by plants and carbon sequestration and storage by trees—would help individuals, governments and businesses appreciate them more and make them more likely to integrate these ecosystem-service values into future policy and land use decisions. This is an idea that has long been advocated by economists: reduce the overconsumption of natural resources by making people pay the full price for their use (hence their overwhelming support for water pricing and a carbon tax scheme). The best way to ensure the successful restoration of threatened habitats, the authors explain, is to devolve more authority to local communities, which are naturally more invested in them. Poor communities in developing countries, which depend on their habitats for food, shelter and other resources, will be much more likely to protect their surroundings if they are made aware of the consequences of habitat degradation. Furthermore, imbuing local leaders with the knowledge and skills to manage and preserve their habitats will build local capacity and generate more grassroots support for conservation planning—an enthusiasm that is likely to be passed on to future generations.

Perhaps the simplest, and most obvious, solution the authors suggest is to get biodiversity back onto the “cultural radar screen”—to convince people that it is not their large homes, SUVs, clothing, and big screen TVs that they should value most, but the beauty and plentiful ecosystem services offered by nature. A herculean task, to be sure, but one that should be vigorously pursued by all educators and policymakers. Only by instilling in our children and grandchildren an appreciation for nature that can “rival virtual reality as a source of entertainment, intrigue, and inspiration,” can we make sure that the biodiversity crisis is eventually resolved.

Jeremy Jacquot is a graduate student in marine environmental biology at the University of Southern California and is the Los Angeles correspondent for TreeHugger.com.

The U.S. Climate Change Science Program defines abrupt climate change as: “a change in the climate that takes place over a few decades or less, persists for at least a few decades, and causes substantial disruptions in human and natural systems.” A good way to wrap your head around this is to think through an analogy. Say you’re sitting in a canoe and you start leaning over the side. At first, you’ll only cause a slight tilt. Continue to lean over, however, and you’ll suddenly cause the canoe to flip over—with you ending up in the water. Now imagine the canoe represents Earth and your leaning over represents fossil fuel use, or any other climate-affecting anthropogenic activity. Push against Earth only slightly, and you may experience rising temperatures or increased aridity; push just a bit harder though, and you may trigger an abrupt climate change. Like flipping an upside-down canoe back over, returning to a normal climate system isn’t easy—and it takes time.

Abrupt climate changes do happen, but at the present moment, scientists do not have a complete picture of how far we can lean over the side of our Earth-shaped canoe before tipping into a spiral of dramatic climactic disruptions. And that makes it all the more importance to curb greenhouse gas emissions sooner rather than later, when they have reached atmospheric concentrations well beyond the horizon of current climate models.

Most of the scientific evidence we have of past abrupt climate changes comes from a variety of sources, including tree rings, pollens, ice caps, and the sediment record. Arguably the best-studied abrupt climate change event, the Younger Dryas, which took place around 12,800 years before present, resulted in the planet being plunged into frigid conditions. Named after Dryas Octopetala, a plant commonly found in colder climates, the period lasted roughly 1,200 years before ending abruptly—following a sudden 10°C temperature jump over the span of only 10 years. While there remains disagreement over the exact cause of the Younger Dryas, the two most oft-cited explanations are a shutdown of the ocean conveyor belt, also called thermohaline circulation, or THC, and the interruption of the El Niño-Southern Oscillation.

The first conjecture is the reason why scientists are so concerned about the Antarctic and Greenland ice sheets melting. The sudden massive influx of freshwater could potentially overwhelm the ocean conveyor belt, plunging the planet once more into a period of near-glacial conditions. Wallace Broecker of the Lamont-Doherty Earth Observatory at Columbia University, one of the world’s most renowned climate experts, and the man who coined the term “global warming,” has called THC the “Achilles heel of our climate system.” In a speech delivered to the World Economic Forum in 2003, Robert Gagosian, the former president of the Woods Hole Oceanographic Institution, warned that its shutdown could cool certain parts of the planet by 3°C to 5°C and cause prolonged droughts elsewhere. The areas most affected by this shutdown would be those bordering the North Atlantic—in effect, some of the world’s most developed countries.

A more recent example of abrupt climate change can be traced back to the 1920s, when a warming of 4°C on the Atlantic side of the Arctic helped precipitate an extended drought during the following decade—now more commonly known as the Dust Bowl. Or take the drought that afflicted Africa’s Sahel region for over two decades, into the early 1980s, and caused a widespread famine that killed millions. The National Oceanographic and Atmospheric Adminstiration’s Geophysical Fluid Dynamics Laboratory, which studied its climatic implications, concluded that changes in sea surface temperatures over large areas—the result of natural climate variations and anthropogenic activities—were to blame.

The ecological impacts of abrupt climate change, as might be expected, can be devastating. Unlike periods of slow, gradual climate change, which afford humans and other organisms some time to adapt to their changing conditions, abrupt climate changes can strike on short notice—leaving long-lived, sedentary organisms at a severe disadvantage. Though lacking in some respects, especially compared to the body of research on the effects of climate change, evidence from the sedimentary record indicates that local extinctions and large-scale ecosystem disturbances were common. Many North American mammal extinctions almost coincide with the advent of the Younger Dryas event, while ecosystem shifts in the northeastern and central Appalachian United States were recorded as taking place less than 50 years following its conclusion. With world population levels now bearing down on 7 billion, an abrupt climate change event would have devastating ecological and economic impacts.

A recent report released by the U.S. Climate Change Science Program considered the potential impacts of four types of abrupt climate change could have on the planet if they took place in the near future: the rapid melting of glaciers and ice sheets, the widespread and sustained changes to the water cycle, changes in the thermohaline circulation, and the release of methane trapped in permafrost and on ocean floors. While the report readily acknowledges that rapid changes in the Earth’s climate will likely persist for the foreseeable future, it concludes that an abrupt climate change is highly unlikely—at least in the short-term. This reflects the views of a majority of climate scientists, who peg the probability of an abrupt climate change event at less than one in five.

What worries some, however—and is one of the main reasons why it remains such a contentious topic—is that our understanding and modeling of key global processes, such as deep water formation, give us an incomplete picture. Few scientists expected the Arctic ice cap to melt as fast as it has—some now predict it could be gone by 2013—and many are troubled by the speed at which methane, a greenhouse gas that is more than 20 times as powerful as carbon dioxide, is being released from thawing permafrost in the Arctic. The only way to avert abrupt climate change, some are now arguing, is to use geoengineering—a set of controversial schemes aimed at tweaking our planet out of harm’s way. Others point to the need for more effective mitigation strategies, paired with a stronger emphasis on research. In the end, it may be that only a combination of these distinct approaches proves sufficient to prevent the next abrupt climate change.

Maybe the National Research Council put it best when it stated the following in its 2002 report: “It is important not to be fatalistic about the threats posed by abrupt climate change.”

Jeremy Jacquot is a graduate student in marine environmental biology at the University of Southern California and is the Los Angeles correspondent for TreeHugger.com.

With international efforts to reach consensus on a successor to the Kyoto Protocol stalled, many scientists are arguing that drastic measures will be needed to prevent the worst excesses of climate change.

Geoengineering is loosely defined as the intentional large-scale manipulation of the environment in order to blunt man-made climate change.^[1] Once derided as little more than a mere distraction from the serious business of climate mitigation, the idea that humans may need to “tweak” the planet to avert a major catastrophe has gained currency in recent years. This shift in thinking has been spurred in part by the unprecedented nature of recent environmental shifts, such as the melting of the Arctic ice caps and the rapid acidification of the world’s oceans. These events, in addition to other clear instances of climate change, have cast into doubt even scientists’ most pessimistic scenarios. And while there remains a solid contingent of scientists who vehemently oppose geoengineering on scientific and ethical grounds, there is some indication that the tide may slowly be turning in favor of its advocates. With international efforts to reach consensus on a successor to the Kyoto Protocol stalled, many scientists are arguing that drastic measures will be needed to prevent the worst excesses of climate change.

The term geoengineering, as we know it today, was originally coined in the early 1970s by Cesare Marchetti, an Italian physicist, who used it to describe the injection of carbon dioxide into the deep ocean as a potential scheme for climate change mitigation.^[2] At the time, the U.S. had already discovered cloud seeding, a form of weather modification which increases precipitation by injecting chemicals such as silver iodide or dry ice into clouds, and was hastily stepping up its research into weather and climate modification to counter the Soviet Union’s dominanant position in the field at the time. Over the ensuing years, the practice of cloud seeding would fall out of favor, soon to be replaced with a newfound focus on the relationship between CO2 and climate change. The first government reports to seriously consider geoengineering as a potential countervailing measure were issued by the National Academy of Sciences in 1983 and 1992. The four options examined in the 1992 report were: reforestation, ocean fertilization, albedo modification, and the removal of atmospheric chlorofluorocarbons. Two of these—ocean fertilization and albedo modification—are at the center of the current debate over geoengineering.

Albedo refers to an object or surface’s ability to reflect solar radiation and is expressed as a value between zero and one; a colored surface with an albedo of 0.45, for example, would reflect 45 percent of the sunlight that falls upon it. Albedo modification schemes therefore intend to offset the warming effect of higher greenhouse gas concentrations by increasing the planet’s albedo. The most famous (some might say infamous), and well-studied, scheme consists of pumping sulfur dioxide into the stratosphere to reflect a slice of incoming solar radiation. Sometimes referred to as “sunshade” geoengineering, it is most commonly associated with Ken Caldeira, a scientist at Stanford University’s Carnegie Institution, and Lowell Wood (sometimes dubbed Dr. Evil), formerly of the Lawrence Livermore National Laboratory. Paul Crutzen, a 1995 Chemistry Nobel Laureate best known for his work on ozone depletion, lent his imprimatur to the scheme by publishing an essay in 2006 arguing in its favor.^[3] Caldeira and Wood believe injecting a million tons of sulfur dioxide into the stratosphere would reflect one to three percent of the sun’s rays—enough to counteract the warming impacts of climate change. The sulfur dioxide would be carried up to the stratosphere by a fleet of converted 747s, military fighters, or even large balloons. They estimate such a plan would cost roughly $1 billion a year.

The blooms, when they die off, release most of the carbon back to the atmosphere, thus causing no permanent reduction in atmospheric emissions.

The idea for ocean iron fertilization arose from John Martin, a renowned oceanographer who drew national attention for his pioneering work on the “iron hypothesis” when he jokingly told an audience at the Woods Hole Oceanographic Institution, “Give me a half tanker of iron, and I will give you an ice age.” According to this controversial theory, large blooms of unicellular, plant-like phytoplankton could be stimulated in certain parts of the ocean, called high-nutrient, low-chlorophyll zones, or HNLCs, by dumping relatively small quantities of iron dust into the water. Martin believed the blooms would be able to absorb enough atmospheric carbon dioxide so as to slow and even partially reverse climate change. This theory hinged on the notion, now widely debated, that the absorbed carbon would sink to the bottom of the ocean when the blooms eventually collapsed—thus sequestering it.

The evidence obtained from the 12 fertilization experiments carried out since his pronouncement has largely been inconclusive, due in part to the fact that most have operated under less than ideal conditions or have been too short.^[4] Initial results do seem to suggest that the sequestration effect is only temporary—that the blooms, when they die off, release most of the carbon back to the atmosphere, thus causing no permanent reduction in atmospheric emissions. Despite the uncertainty, Climos, a San Francisco-based startup, sees an opportunity to make money selling carbon credits by organizing large-scale iron fertilization expeditions. Dan Whaley, the company’s CEO, insists Climos will not begin to sell carbon credits until the evidence is there and has pledged to work with the scientific community and international bodies to ensure its efforts abide by regulatory standards.

Whether any of these schemes proves to have staying power remains to be seen. Several recent studies have demonstrated that the risks of albedo modification could far outweigh the potential benefits. Reducing the amount of sunlight reaching the planet could slash global precipitation levels, possibly leading to more droughts. Another study explicitly linked sulfur injection to a depletion of the ozone layer. Simone Tilmes, the lead author, found that it would severely weaken the ozone layer for several decades and delay the recovery of the ozone hole by up to 70 years. In late May, close to 200 countries attending a United Nations conference voted to place a moratorium on the practice of ocean fertilization, potentially putting Climos’s future plans at risk. The decision will now be referred to the London Convention, a subset of the International Maritime Organization charged with regulating the disposal of wastes at sea, which is expected to deliberate on the issue within the coming months.

In the end, whether or not we decide to pursue geoengineering will boil down to a single question: How far are we willing to push our fragile planet in order to avert the looming climate crisis?

Jeremy Jacquot is a graduate student in marine environmental biology at the University of Southern California and is the Los Angeles correspondent for TreeHugger.com.

Notes

[1] Keith, D. W. 2000. “Geoengineering the climate: History and prospect,” Annu. Rev. Energy Environ., 25: 245-284.

[2] Ibid.

[3] Crutzen, P. 2006. “Albedo enhancement by stratospheric sulfur injections: A contribution to resolve a policy dilemma?” Climactic Change, 77: 211 – 219.

[4] Boyd, P. W. et al. 2007. “Mesoscale iron enrichment experiments,” 1993-2005: Synthesis and future directions, Science, 315: 612 – 617.

Much of the blame has been laid on anthropogenic activities, such as rising farm production and energy consumption, and the imbalances they have created in the global and phosphorus cycles.

While the Gulf dead zone may be the best-studied (and most infamous) example, many others—over 43, at last count—have sprung up around the country in recent decades, most noticeably in the Chesapeake Bay and off the coasts of Oregon and Washington.^[1] Ranging widely in size from small areas in coastal bays to vast swathes of water in the open ocean, they are typically located in temperate seas. According to a 2004 United Nations report, there are now over 150 documented dead zones around the world. Another report found that the number of dead zones had roughly doubled every decade since the 1960s.^[2]

And here’s the kicker: While most are still seasonal, climate change could prolong these events—and make them much more frequent.

One of the world’s longest river systems, and the country’s largest carrier of river-borne nutrients, the Mississippi River drains 41 percent of the contiguous United States.^[3] At the mouth of this system lies the planet’s second largest zone of oxygen-depleted waters—the Gulf dead zone—that is estimated to cover an area greater than 10,000 square miles this year. Over the past few decades, a number of studies have cast light on the causes and impacts of such hypoxia events.

Much of the blame has been laid on anthropogenic activities, such as rising farm production and energy consumption, and the imbalances they have created in the global nitrogen and phosphorus cycles—increasing these key nutrients’ availability to coastal and ocean ecosystems. The presence of these excess effluents stimulates the rapid growth of phytoplankton, microscopic plant-like organisms, producing massive blooms. When they eventually deteriorate and sink to the seafloor, they are feasted upon by a vast array of microorganisms, which consume all of the available oxygen in the surrounding waters—creating anoxic, or dead, zones. Well-oxygenated waters typically contain up to 10 milligrams of oxygen per liter, or 10 parts per million (ppm). In hypoxic zones, by contrast, the concentration of dissolved oxygen often falls below 2 ppm; in some cases, it can plunge below 0.5 ppm and remain there for several months—leaving behind an area completely devoid of life. This process, which significantly reduces biodiversity and alters entire food webs, is known as eutrophication.

There is great concern among scientists and government officials that booming corn production could seriously harm these already stressed waters. U.S. farms are expected to produce record amounts of heavily fertilized food crops, and the government is signaling that it may free up even more land to plant corn. Combine this with the huge input of farm runoff the floodwaters from the Midwest will bring, and the result is the largest dead zone ever seen in the Gulf. With agricultural production likely to maintain its upward trend—especially in light of the current food crisis—and with more unprecedented weather events in the offing, such problems will become more commonplace.

Indeed, some scientists fear that global warming has already aggravated and prolonged dead zone events off the coasts of Oregon and Washington. Jane Lubchenco, a marine ecologist at Oregon State University, believes that the stronger winds produced as land heats up are prolonging upwelling in coastal waters.^[4] Upwelling is the process by which deep, nutrient-rich waters are driven up to the surface by winds; it provides a vital source of food that stimulates much of the ecosystem’s primary production. In this case, however, too much of a good thing can be harmful. An excess of phytoplankton that isn’t consumed will die and fall to the seafloor, creating large, oxygen-free zones. Worse, Lubchenco and her colleagues found that the low-oxygen areas, which typically reside in deep waters, are spreading to shallow fishing waters—a discovery Francis Chan, a fellow ecologist, described as “unprecedented.”

Efforts begun by the federal and state governments in 2001 to rein in these problems have yielded precious little by way of results. The original proposal, intended as a coordinated federal plan to shrink the dead zones by making cuts to nutrient runoff, never made it past the budget process once the Bush administration took office. A revised plan led by the Environmental Protection Agency would maintain the dual objectives of shrinking the Gulf dead zone to about one-quarter of last summer’s size by 2015 and of slashing nitrogen and phosphorus levels by 45 percent apiece. Yet because the plan mandates that states complete their implementation strategies by 2013, leaving only two years to achieve the necessary reductions, some scientists have already criticized it as being toothless and backward-minded.

At this rate, it is clear that we may be close to reaching a tipping point after which dead zones will be considered the “new normal,” as Lubchenco puts it. The consequences will be devastating: completely altered ecosystems, dwindling biodiversity and exhausted fisheries populations, to name a few. Buffeted by other forces, including acidification and thermal expansion, our oceans may have already passed the point of no return.

Jeremy Jacquot is a graduate student in marine environmental biology at the University of Southern California and is the Los Angeles correspondent for TreeHugger.com.

Notes

[1] Dybas, C.L. 2005. Dead zones spreading in world oceans. BioScience 55(7): 552 – 557.

[2] Dybas, C.L. 2005. Dead zones spreading in world oceans. BioScience 55(7): 552 – 557.

[3] Rabalais, N.N. et al. 2002. Beyond Science into Policy: Gulf of Mexico Hypoxia and the Mississippi River. BioScience 52(2): 129 – 142.

[4] Chan, F. et al. 2008. Emergence of anoxia in the California current large marine ecosystem. Science 319: 920.

The unprecedented influx of anthropogenic CO2 emissions since the 1800s has fundamentally altered the equation.

Starting in the late 1950s with the groundbreaking research of Roger Revelle and Charles Keeling, scientists have long been aware of the essential role played by the ocean in mitigating the impact of elevated atmospheric carbon dioxide (CO₂) levels. Ice core record measurements of carbon dioxide taken mid-century showed that atmospheric concentrations had remained about constant for several thousand years until the rapid onset of industrialization during the 1800s, after which they began their meteoric rise. Revelle’s work was instrumental in demonstrating that a large fraction of the gas remained in the atmosphere. At the same time, it also suggested that a significant amount was being absorbed by the ocean—a realization that would lead him to conclude that, over the long term, it would permanently change the chemistry of seawater. A number of oceanographer-led global surveys completed in 2004 determined that the ocean had absorbed nearly half of all carbon emitted since the start of the Industrial Revolution. Other studies have found that around a third of fossil fuel-derived CO₂ is currently taken up by the ocean ^[1].

Upon entering the ocean, a portion of CO₂ reacts with water to form carbonic acid, a weak acid; the other portion stays in dissolved form. Some fraction of the acid will then release hydrogen ions into solution, yielding either bicarbonate or carbonate ions, while a smaller fraction will remain as carbonic acid. The relative proportion of these three forms of dissolved inorganic carbon—carbon dioxide, bicarbonate ions and carbonate ions—acts as a natural buffer, called the “carbonate buffer,” by absorbing small pH changes induced by the increase in hydrogen ion concentration. The pH scale, which ranges from 0 to 14, is used by scientists to measure a solution’s acidity or basicity—the lower the value, the more acidic the solution. The scale is logarithmic, so a one-pH unit drop corresponds to a ten-fold increase in the hydrogen ion concentration, making seawater more acidic. With an average pH of 8.1, seawater is considered slightly basic, or alkaline.

This buffering system has helped keep the ocean’s pH in check for thousands of years. However, the unprecedented influx of anthropogenic CO₂ emissions since the 1800s has fundamentally altered the equation, threatening to overwhelm the delicate balance maintained by this system and tipping the ocean into a period of prolonged acidification. The problem is simple: as increasing amounts of atmospheric CO₂ are absorbed by surface waters, more hydrogen ions are formed—which leads to an overall decrease in seawater pH. Many of these hydrogen ions will combine with carbonate ions, forming bicarbonate ions and reducing the concentration of carbonate ions. The net effect is to weaken the carbonate buffer, rendering it less effective at keeping slight pH variations in check.

By some estimates, all of the planet’s corals could disappear by century’s end if present trends continue.

Researchers believe this process lowered the oceans’ average pH by 0.1 since the pre-industrial era—equivalent to a 30 percent increase in the ocean’s average hydrogen ion concentration ^[2]. A recent analysis postulated that pH levels might fall by as much as 0.5 units by 2100, which would be equivalent to a three-fold increase in the hydrogen ion concentration since pre-industrial times ^[3]. The impacts of ocean acidification are already being felt closer to home: a report published just this past month in Science showed evidence for the upwelling of “acidified” water onto the Pacific continental shelf between central Canada and northern Mexico. Seasonal upwelling, which brings nutrient-rich deep waters up to the surface, is a natural phenomenon in this region and one that is critical for many developing marine organisms.

“So what?” you may ask. Why should I care about this when other climate-induced phenomena like heat waves and droughts seem much more urgent? Diminishing the ocean’s capacity to absorb CO₂ is no small problem in itself, because without the ocean serving as a carbon sink, more carbon dioxide will have no where to go but into the atmosphere. But aside from that, what worries scientists most about ocean acidification is that it will inhibit certain organisms’ ability to produce calcium carbonate shells—to the extent that they would have great difficulty growing. And not just any organisms: those, like phytoplankton, which support entire food webs by acting as the ocean’s primary producers (like plants in terrestrial ecosystems). Without them—or with their numbers greatly reduced—many populations and ecosystems could simply collapse. Moreover, oceanographers are deeply concerned about the potential impact of acidification on corals. These tiny organisms, which secrete calcium carbonate skeletons that, over time, accumulate to form large reef assemblages, could become more prone to so-called “bleaching” episodes—in which algae that form symbiotic associations with the corals (and give them their colors) are expelled, depriving the latter of a critical source of nutrients. Worse, the precipitous drop in carbonate ion concentration could make many regions of the ocean acidic enough to dissolve calcium carbonate structures ^[4]. Corals, phytoplankton and other calcifying organisms would be unable to survive under such “undersaturated” conditions. By some estimates, all of the planet’s corals could disappear by century’s end if present trends continue. The continued uptake of carbon dioxide from the atmosphere will cause these areas to expand until only a sliver of the ocean’s surface layer remains inhabitable.

That’s not to say that certain species won’t also benefit. Indeed, a few recent studies have demonstrated that some phytoplankton species may thrive under conditions of elevated CO₂ concentrations. Larger organisms, like seagrasses, use dissolved carbon dioxide directly and could therefore also experience gains. While the current state of research may be ambiguous in some areas, it is clear that the overall picture is decidedly grim. Though more studies are needed, scientists are concerned that acidification is taking place at such speed that we—let alone marine species—will have little time to adapt.

Jeremy Jacquot is a graduate student in marine environmental biology at the University of Southern California and is the Los Angeles correspondent for TreeHugger.com.

Notes

[1] Doney, S.C. 2006. The dangers of ocean acidification. Scientific American: 58 – 65.

[2] Brewer, P.G. 1997. Ocean chemistry of the fossil fuel CO2 signal: the haline signal of “business as usual”. Geophys. Res. Lett. 24: 1367 – 1369.

[3] Caldeira, K. and Wickett, M.E. 2003. Anthropogenic carbon and ocean pH. Nature 425: 365.

[4] The Royal Society. 2005. Ocean acidification due to increasing atmospheric carbon dioxide.

Before delving into nitrogen’s environmental impacts, however, it might help to first take a step back and ask: Why exactly should we care about the nitrogen cycle? Well, for one thing, most of the air we breathe is nitrogen gas: Fully 78 percent of the atmosphere is made up of nitrogen—by comparison, oxygen, the gas most of us associate with life, constitutes only 20.9 percent of the atmosphere [1]. While most of it is unavailable for use by organisms, nitrogen is ubiquitous in our natural environment and is vital to all life processes. The forms of the element we use in our bodies, which must be converted through a process called fixation, are collectively known as “reactive” nitrogen; examples of these abound and include ammonia, proteins, and amino acids.

Until the 20th century—and the advent of the modern industrial revolution—there existed only a limited number of microorganisms capable of fixing non-reactive gaseous nitrogen into reactive forms.

Until the 20th century—and the advent of the modern industrial revolution—there existed only a limited number of microorganisms capable of fixing non-reactive gaseous nitrogen into reactive forms. As a result, even though the amount of reactive nitrogen produced was limited—especially in light of the needs of our rapidly growing population—the global nitrogen cycle remained balanced. The invention of the Haber-Bosch process in the early part of the century, which provided an industrial-scale method to produce reactive nitrogen for agricultural purposes (mainly in the form of fertilizers), would revolutionize the pace of global development—helping sustain ever-higher population levels—and fundamentally alter the natural nitrogen cycle. The biogeochemical gears this invention set in motion would be further exacerbated by the world’s increased reliance on fossil fuels.

In 1970, Constant Delwiche, then a professor of soil biogeochemistry at the University of California, Davis, cautioned that, “The ingenuity that has been used to feed a growing world population will have to be matched quickly by an effort to keep the nitrogen cycle in reasonable balance” [2]. Since Delwiche’s prescient observations almost four decades ago, the world population—buoyed by the advances made under the “Green Revolution”—has increased by 78 percent. At the same time, the creation of reactive nitrogen has jumped by 120 percent. Thanks in large part to this industrial breakthrough, the most dire predictions made by Thomas Malthus and his modern adherents—predicated upon the belief that population growth would far outpace agricultural growth—never came to pass.

How do we manage to both significantly reduce the amount of nitrogen in some parts of the world while greatly increasing it in others?

While there is no denying that increased nitrogen production has been a boon for the world community—helping accommodate growing populations and alleviating poverty and hunger worldwide—it has also incurred many significant environmental costs. Air pollution, coastal eutrophication (which over-saturates waters with minerals and drives out animal life), and accelerated global warming trends, are just a few. Indeed, James Galloway, a professor of environmental sciences at the University of Virginia and the lead author on one of the articles, calls this the “cascade” effect [3]: the notion that every atom of reactive nitrogen can spur a cascading sequence of events which harms ecosystem and human health. These events can trigger terrestrial and aquatic ecosystem-wide shifts in biodiversity, facilitating the introduction of invasive species and corrupting the systems’ underlying stability. Worse still, as mentioned above reactive nitrogen can also alter the delicate balance of other greenhouse gases—including carbon dioxide and methane—and speed up ozone depletion.

Despite this growing imbalance, many areas of the world remain severely nitrogen-limited—primarily large regions in Africa and Latin America, where more cropping depletes more reactive nitrogen than fertilizers replenish. According to Galloway and his colleagues, 800 million individuals, or close to 15 percent of the world’s population, suffer from this “fertilizer deficit.” This then raises a difficult paradox: How do we manage to both significantly reduce the amount of nitrogen in some parts of the world while greatly increasing it in others? Or, as Galloway puts it, how do we, “maximize the benefits of anthropogenic Nr while minimizing its unwanted consequences”? Evidently, no single strategy will be sufficient to resolve these vexing issues.

Governments in the developed world should adopt a multifaceted, targeted approach to reducing the amount of excess reactive nitrogen by concentrating on the following objectives: reducing the amount of nitrogen oxide emissions produced during fossil fuel combustion; developing renewable energy technologies; increasing the nitrogen-uptake efficiency of crops; and improving animal management strategies. While recognizing that developing countries are primarily focused on increasing food production, the developed world should encourage them to mitigate their negative impacts while ensuring their access to fertilizers and clean energy technologies. When combined, these interventions would represent a substantial decrease in the amount of reactive nitrogen produced every year; implementing this approach would help offset some of the increases necessary to foster continued growth in agricultural production. Because these processes transcend both political and geographical boundaries, it will become necessary for governments to cooperate and to develop an integrated approach to managing nitrogen production.

Getting there won’t be easy. Put aside the sheer challenge of mounting such a global effort, and you’re still left with the equally daunting task of convincing people they should care as much about their nitrogen footprint as they do their carbon footprint. Given the right incentives, there is no question people can and will adapt—how and when they choose to do so, however, will be key.

Jeremy Jacquot is a graduate student in marine environmental biology at the University of Southern California and is the Los Angeles correspondent for TreeHugger.com.

Notes

[1] Carpenter, E.J. & Capone, D.G. (1983). Nitrogen in the Marine Environment. Academic Press: New York.

[2] Delwiche, C.C. (1970). The nitrogen cycle. Scientific American. 223, 137.

[3] Galloway, J.N. et al. (2003). The nitrogen cascade. BioScience, 53: 153 – 226.