Tiempo Climate Cyberlibrary, Fourth Assessment of Emissions Mitigation

The third report of the Fourth Assessment on climate science and policy by the Intergovernmental Panel on Climate Change, covering mitigation options, was finalized in May 2007. Newswatch editor Mick Kelly reports.

The Intergovernmental Panel on Climate Change (IPCC) released the third report in its latest assessment of climate science and policy on May 4th in Bangkok, Thailand. The Working Group III review covers means of limiting the rise in atmospheric concentrations of greenhouse gases. It concludes that the cost of climate-control measures can be relatively small and might even benefit the economy, but warns that emissions must start declining by the year 2015 to prevent global temperature rising more than two degrees Celsius above the pre-industrial baseline. "The time to act is now," Chartree Chueyprasit of Thailand's Ministry of Natural Resources and Environment told government officials and scientists as they met to finalize the text.

The IPCC assessment notes that a wide range of technological options, already available and under development, can be deployed to limit global warming. "The most important thing is to improve energy efficiency," commented Jean-Pascal van Ypersele, a member of the Belgian delegation. "There is a lot of energy wasted everywhere in the world," he continued. Other options include converting from coal to natural gas, greater use of renewable energy and the safe deployment of nuclear power. The report also advocates making buildings more energy-efficient and motor vehicles more fuel-efficient, reducing deforestation and tree planting to absorb carbon. Hans Verolme of WWF said that "the IPCC has delivered a road map for keeping the planet safe. Now it's the turn of politicians to do more than pay just lip service."

In the United States, the Bush administration welcomed the range of climate mitigation options defined by the report, but did express serious reservations about the more expensive scenarios that could cut world gross domestic product by three per cent. "There are measures that come currently at an extremely high cost because of the lack of available technology," warned James Connaughton, head of the White House Council on Environmental Quality. "Well, that would of course cause global recession, so that is something that we probably want to avoid," he continued.

There had been considerable debate over the final wording of the report. "It's especially troubling that the Bush administration was seeking last-minute changes to play down the report's conclusion that quick, affordable action can limit the worst effects of global warming," said Larry Schweiger, president of the National Wildlife Federation. Chinese delegates had been "masters of deception and the art of interpretation," according to a German environment ministry official, in arguing that it would cost more and be much harder to reduce greenhouse gas emissions than the draft report suggested.

The review's endorsement of nuclear technology was strongly opposed by some environmentalists. "Nuclear power threatens humans and the environment. It is not necessary to combat climate change," said Brent Blackwelder of Friends of the Earth. Greenpeace accused the IPCC of underestimating the impact of the Chernobyl nuclear accident. "Denying the real implications is not only insulting to the thousands of victims, but it also leads to dangerous recommendations," said Greenpeace's Ivan Blokov.