Global Warming Approaching

Several effects of warming compound each other in synthesis. For example, shrinking snow cover, with its high reflectivity, allows polar surfaces to absorb more heat on sea and land. The warming of land surfaces melts permafrost, which releases larger amounts of carbon dioxide and methane. The cycle reinforces itself. 

Researchers have reported in Nature that Earth’s ancient stores of peat are gasifying into the atmosphere at an accelerating rate that is adding significantly to the atmosphere’s overload of greenhouse gas. Given the fact that one-third of the Earth’s carbon is stored in far northern latitudes (mainly in tundra and boreal forests), the speed with which warming of the ecosystem releases this carbon dioxide to the atmosphere is vitally important to forecasts of global warming’s effects. The amount of carbon stored in arctic ecosystems also comprises two-thirds of the amount presently found in the atmosphere. Its release into the atmosphere will depend on the pace of temperature rise—and the Arctic, according to several sources, has been the most rapidly warming region of the Earth. 

During 2004, Michelle C. Mack and colleagues presented results in Nature of a 20-year fertilization experiment in Alaskan tundra during which “increased nutrient availability caused a net ecosystem loss of almost 2,000 grams of carbon per square meter.” While aboveground plant production more than doubled under warmer conditions, “losses of carbon and nitrogen from deep soil levels…were substantial and more than offset the increased carbon and nitrogen storage in plant biomass and litter.” According to this study, increased releases of carbon to the atmosphere “primed” by increasing decomposition of organic matter could accelerate the rise in atmospheric carbon dioxide—and, therefore, warming. 

Greenhouse Gases and Wildfires  

I ncreasing wildfires are accelerating global warming. Under some circumstances, wildfires may emit more carbon dioxide than humankind’s contribution. What’s more, many present-day computer simulations of climate change usually do not take fires’ contributions into account. 

Widespread wildfires during the summer of 2002 changed areas of the U.S. west from a carbon “sink” (absorber) to a net carbon source, as drought stunted tree growth, according to computer modeling studies of fires in Colorado conducted by a team of researchers from Colorado State University, the U.S. Geological Survey, and the National Center for Atmospheric Research. “We’re using the western United States as a case study area where climate and land use are interacting in several interesting ways,” said NCAR senior scientist David Schimel. Western lands, particularly evergreen forests, represent about half of all U.S. carbon storage, he said. More carbon is freed from storage during droughts, not only because more dry vegetation burns, but also because plants deprived of water grow slower, absorbing and storing less carbon in their tissues. 

Another important source for carbon dioxide has been provided by Indonesian fires that polluted air over Southeast Asia during the El Niño years of 1997 and 1998. An area twice the size of Belgium burned in Indonesia during 1997. Susan Page at Britain’s University of Leicester, together with colleagues in England, Germany, and Indonesia, analyzed satellite photos and data gathered on the ground to estimate how much of the fire area’s living vegetation and peat deposits burned. 

In Indonesia, layers of peat as thick as 20 meters (66 feet) cover an area of about 180,000 square kilometers (112,000 square miles) in Kalimantan (Borneo), Sumatra, and Papua New Guinea (formerly Irian Jaya). Page and colleagues used satellite images of a 2.5 million hectare study area in Central Kalimantan from before and after the 1997 fires. According to their estimates, about 32 percent of the area had burned, of which peat land accounted for 91.5 percent. An estimated 0.19 to 0.23 gigatons of carbon were released to the atmosphere through peat combustion, with a further 0.05 gigaton released from burning of the overlying vegetation. Extrapolating these estimates to Indonesia as a whole, the researchers estimated that between 0.81 and 2.57 gigatons of carbon were released to the atmosphere in 1997 as a result of burning peat and vegetation in Indonesia. 

Page and colleagues reported in Nature that the carbon dioxide released by these fires was “equivalent to 13 to 40 percent of the mean annual global carbon emissions from fossil fuels and contributed greatly to the largest annual increase in atmospheric CO 2 concentration detected since records began in 1957.”  

Robert Cowen of the Christian Science Monitor wrote: “Drought due to the 1997 El Niño was all that was needed to make the circumstances right for a sustained conflagration when forest-clearing fires were lit that year. ”  

Page and her colleagues explained the difficulty of calculating exactly how much carbon dioxide the fires emitted, but the totals were massive, especially when one adds to Indonesia’s fires the many others that have burned around the globe, notably during North America’s intense drought. The work of Page and colleagues has major implications for climate-change modeling because, as they wrote in Nature : “Tropical peat lands are one of the largest near-surface reserves of terrestrial organic carbon, and hence their stability has important implications for climate change. In their natural state, lowland tropical peat lands support a luxuriant growth of peat swamp forest overlying peat deposits up to 20 meters thick. Persistent environmental change—in particular, drainage and forest clearing—threatens their stability, and makes them susceptible to fire. This was demonstrated by the occurrence of widespread fires throughout the forested peat lands of Indonesia during the 1997 El Niño event.” 

Jack Rieley, at the University of Nottingham, UK, believes that burning peat in Borneo is a major factor in rapidly rising atmospheric carbon-dioxide levels. As farmers continue to clear the forests by burning, the bogs catch fire and release carbon for months afterwards. A biologist from Borneo told New Scientist late in 2004 that the fires have now returned after an earlier peak during an El Niño-provoked drought in 1998. “During October [2004], the atmosphere around Palangka Raya has been covered in thick smoke, with visibility down to 100 meters. The schools have been shut and flights cancelled,” said Suwido Limin from the University of Palangka Raya in the Indonesian province of Central Kalimantan. 

The fires in Indonesia have had other environmental effects as well. Iron fertilization of Indian Ocean waters resulting from the massive wildfires may have played a crucial role in producing a red tide of historic proportions that severely damaged coral reefs, according to Nerilie J. Abram and associates, writing in Science . Their findings “highlight tropical wildfires as an escalating threat to coastal marine ecosystems.” 

The spread of human populations is aggravating fire dangers around the world. The fires that ravaged much of Indonesia during 1997 and 1998 were caused, in part, by drought-provoked El Niño conditions. They were intensified, however, by local farmers hired to set fires at the behest of local developers to open forest land for farming and grazing. The fires were illegal under Indonesian law if they were set in protected areas—but not if they could be blamed on El Niño, a natural condition. At least 29 companies later were indicted for setting illegal fires in Indonesia’s rainforests. 

Page and colleagues pointed out, “In Indonesia, peat land fires are mostly anthropogenic, started by local (indigenous) and immigrant farmers as part of small-scale land clearance activities and, on a much larger scale, by private companies and government agencies as the principal tool for clearing forest before establishing crops.” During the unusually long El Niño dry season of 1997, many of these “managed” fires spread out of control, “consuming not only the surface vegetation but also the underlying peat and tree roots, contributing to the dense haze that blanketed a large part of Southeast Asia and causing both severe deterioration in air quality and health problems.” 

Commenting on Page’s study in Nature , David Schimel and David Baker of the National Center for Atmospheric Research in Boulder, Colorado noted that two other independent studies of atmospheric carbon-dioxide concentrations during that time period support the conclusion that the fires were a major contributor to atmospheric carbon-dioxide levels. Schimel and Baker told Cowen that computer climate simulations assume that processes which emit carbon dioxide and remove it from the atmosphere operate smoothly and continuously. Episodic events such as wildfires play havoc with such simulations. 

At present, no climate modeler knows exactly how to factor catastrophic events in small areas that release carbon dioxide that has been locked away in peat or other carbon and methane reservoirs into world-scale forecasts of greenhouse-gas levels. Such events can evidently have a huge impact on the global carbon balance, Schimel and Baker believe. During 1997 the growth rate of carbon dioxide in the atmosphere was double the usual rate, reaching its highest level on record to that time, in large part because of these peat fires. Most of the carbon injected into the atmosphere during the Indonesian fires resulted from burning peat rather than combustion of trees. 

The Kyoto Protocol 

G lobal greenhouse-gas emissions are rising and evidence of a warming planet are developing much more quickly than world diplomacy has been able to address them. The snails-pace nature of consultative diplomacy combines with the fact that we feel the results of fossil-fuel effluvia perhaps 40 years after the fact (through a complex set of natural feedbacks) to create a trap in which human responses to global warming take place several decades after nature requires them. 

Given these circumstances, the Kyoto Protocol may be a climatic dead letter, even though its approval by Russia in September 2004 produced world-wide implementation on paper. Russia joined 124 other countries in ratifying the protocol and, with its 17.5 percent share of world-wide carbon-dioxide emissions, raised the world percentage to slightly more than 60 percent, above the 55 percent required to bring Kyoto into force. Seven years after its negotiation in 1997, however, the only sizable countries that have come close to meeting Kyoto Protocol target emission reductions have been Great Britain and Germany. Most other signatories have not met their goals and many third-world countries (India and China among them) are not bound by its provisions. 

The Kyoto Protocol has become more of a political rallying cry than a serious challenge to global warming, which is developing much more quickly than diplomacy can adapt. Even if the protocol was to be fully implemented, a projected temperature rise of 2 degrees Celsius by 2050 would be shaved only by 0.07 degree Celsius, according to calculations by atmospheric scientist Thomas M.L. Wigley. In other words, the Kyoto goals are only a small fraction of the reduction in emissions required if world-wide temperature levels are to be stabilized during the 21st century and afterwards. 

Governments around the world have argued over climate-change policy for two decades. The United States, which produces between one-fourth and one-fifth of the world’s greenhouse gases, has ignored the Kyoto Protocol. In the meantime, global emissions of carbon dioxide from fossil-fuel combustion had increased by 13 percent above 1990 levels by the year 2000, mainly due to huge pollution increases in third world nations, as China and India industrialize rapidly on a power base that is fueled mainly by cheap, dirty coal. 

Increases in greenhouse gas emissions would have been higher between 1990 and 2004, except for the collapse of former state socialist economies in Russia and Eastern European nations during the period. Carbon-dioxide emissions for the period rose by 17.8 percent in the United States, from 4.8 billion tons in 1990 to 5.7 billion tons in 2000, while Western European emissions rose by 3.9 per cent. As a result of the dissolution of the Soviet Union and the resulting economic collapse in former Soviet nations and Eastern Europe, carbon-dioxide emissions in these nations fell from 3.7 billion tons in 1990 to 2.6 billion tons, a drop of 30.6 percent. 

Emissions of carbon dioxide and other greenhouse gases from Europe, Japan, the United States, and other industrialized countries could rise by 17 percent from 2000 to 2010, despite measures in place to curb them, according to a United Nations report. “These findings clearly demonstrate that stronger and more creative policies will be needed for accelerating the spread of climate-friendly technologies and persuading businesses, local governments, and citizens to cut their greenhouse gas emissions,” said Joke Waller Hunter, executive secretary of the United Nations Climate Change Convention.