IPCC: Billions face climate change risk

The Fourth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC), released on Apr. 6, finds the impacts of future climate change will be mixed across regions of the world, with drought-affected areas likely to increase in extent and heavy precipitation likely to increase flood risk in other regions. The report is based on data collected since 1970 that was reviewed by IPCC scientists and includes more than 29,000 pieces of data on observed changes in physical and biological aspects of the natural world. It states that while the number and quality of studies of trends in the environment with relationship to climate change has grown, there is still a lack of balance in data, with marked scarcity in developing countries. More than 2,500 scientific expert reviewers from around the world spent six years working on the assessment. The report, "Impacts, Adaptation and Vulnerability," was adopted last week after a line-by-line review by the governments of 131 countries. The summary is an unusual hybrid, crafted by scientists but endorsed by diplomats, thereby gaining political, as well as academic, credibility. This latest report was controversial because it tackled the more uncertain issues of the precise effects of warming and the ability of humans to adapt to them. The assessment details current scientific understanding of the impacts of climate change on natural, managed and human systems, the capacity of these systems to adapt and their vulnerability. Poor will suffer most The IPCC report states, climate change has been observed in ecosystems around the world. Terrestrial as well as fresh-water and marine ecosystems are being affected. It is predicted that the observed impacts will increase and widen in the years to come. Projected climate change-related effects are likely to affect the health of millions of people through increases in malnutrition, heat waves, floods, storms, fires and droughts; increased frequency of cardiorespiratory diseases due to higher concentrations of ground-level ozone related to climate change; and migration of some infectious diseases. People living in poverty would be worst affected. "It's the poorest of the poor in the world, and this includes poor people even in prosperous societies, who are going to be the worst hit," said Rajendra Pachauri, chairman of the IPCC. Pachauri said those people were also the least equipped to deal with the effects of such changes. Globally, the potential for food production is projected to increase with a rise in local average temperature over a range of 1.8 to 5.4 degrees Fahrenheit, but above this it is projected to decrease. Over the course of the century, water supplies stored in glaciers and snow cover are projected to decline, reducing water availability in regions supplied by meltwater from major mountain ranges, where more than one-sixth of the world's population currently lives. The resilience of many ecosystems is likely to be exceeded this century by an unprecedented combination of climate change; associated disturbances such as flooding, drought, wildfire, insects and ocean acidification; and other global change drivers such as land use change, pollution and over-exploitation of resources, the report finds. There is a 50 percent chance that 20 to 30 percent of plant and animal species assessed so far are likely to be at increased risk of extinction if increases in global average temperature exceed 2.7 to 4.5 degrees Fahrenheit. If temperatures rise more than 4 degrees Fahrenheit, the report foresees major changes in ecosystem structure and function, species' ecological interactions and species' geographic ranges, with mostly negative consequences for biodiversity and for water and food supply. The report finds it very likely that all regions will experience either declines in net benefits or increases in net costs for temperature rises greater than about 3.6 to 5.4 degrees Fahrenheit. But the impacts of climate change will vary with the amount and timing of the change and, in some cases, the capacity to adapt. Fear over diluted climate warnings Some of the world's best-informed scientists walked out of the all-night drafting session of the 21-page report summary regarding how much confidence the scientists have in their findings. The dispute between the scientific authors of the report and its diplomatic editors erupted over a paragraph that originally said scientists had "very high confidence"–which means a 90 percent chance of accuracy–in the statement that many natural systems around the globe "are being affected by regional climate changes, particularly temperature increases." After days of intensive small group negotiations over this section, delegates from China and Saudi Arabia on Apr. 6 insisted that the confidence be reduced to "high confidence," which means 80 percent accuracy. The US eventually brokered a compromise which avoided any watering down of the reference to a "very high confidence" by removing the clause altogether. One of those who left the Charlemagne building in Brussels was Cynthia Rosenzweig, senior research scientist at the NASA Goddard Institute for Space Studies and one of the report's authors. Asked why things got so heated, she replied: "I think that scientists and government representatives are two different groups of people, they have different ways of operating and standards of evidence. When scientists come together with these government people you have some sparks flying." She added: "The lead authors wanted the governments to know that we felt strongly that we have very high confidence that the statement was justified. So I made that point emphatically." Among the delegates there had been a clear spread of views. One observer blamed China and Saudi Arabia for seeking to water down the text, Russia for being "idiosyncratic" and the US for being "difficult in a nuanced way." US negotiators managed to eliminate language in one section that called for cuts in greenhouse gas emissions, said Patricia Romero Lankao, a scientist at the National Center for Atmospheric Research in Boulder, CO, another one of the report's authors. Hans Verolme, director of World Wildlife Fund's climate change program, warned that politics could undermine climate change research "if you have governments questioning the level of scientific confidence or saying 'this is not globally observed' whereas the underlying document says this is a global phenomenon observed by scientists." He predicts that, when the Intergovernmental Panel on Climate Change meets next month in Bangkok to discuss the economic fallout of climate change, "it will be worse." The IPCC was established in 1988 by the World Meteorological Organization and the UN Environment Program and is open to all their member countries. The IPCC does not conduct research on its own but reviews and assesses the most recent scientific, technical and socioeconomic information on climate change. The current IPCC report builds on past assessments including the Working Group I report released in February that confirmed that global warming is occurring, with 90 percent confidence that it is due to human activities. The third part, due on May 4, will focus on ways of curbing the rise in greenhouse gas concentrations and temperature, as well as economics and policy. A fourth report in November will sum up all the findings.