COPENHAGEN—New data released today at the U.N.’s Copenhagen summit helped blunt claims from climate skeptics that global warming has slowed or reversed in recent years. The figures released by the World Meteorological Organization (WMO) show that the last 10 years are the warmest decade in 160 years of record taking. The preliminary figures for 2009—they'll be published in full in March next year, including data from December—also show that this is likely to be the fifth warmest year on record.
The stolen emails story, known by some as SwiftHack and others as ClimateGate, has become a recurring story in the early days of the Copenhagen meeting. The Intergovernmental Panel on Climate Change Chair Rajendra Pachauri was forced to spend part of a press conference he participated in today defending climate science including the work of his Nobel-Peace-Prize-winning panel. Other news coverage at the start of the meeting has focused on the controversy, with CNN, for example, running a story on the issue yesterday titled "Global Warming: Trick or Truth".
The focus on the fundamental science elevated the importance of the WMO announcement, which might otherwise have been the latest voice in a chorus of gloomy reports on climate change. “A central plank of the climate skeptics’ creed has been that the Earth has been cooling since 1998. They have misled many, and damaged public policy as a result. Here is the definitive proof that they are wrong,” said Tim Flannery, professor of environmental and life sciences at Macquarie University in Australia and the chair of the Copenhagen Climate Council, an advocacy group made up of scientists and business leaders. “Unfortunately the warming trend continues, and will continue as long as greenhouse gas concentrations continue to grow,” he said.
The new data shows that average combined air and sea surface temperatures for 2009 were 14.44°C, which is 0.44°C above the average of 14°C documented between 1961 and 1990 used as a baseline to measure warming by WMO, which is based in Geneva, Switzerland.
The figures come from three independent datasets: those of NASA, NOAA, and the Met Office of the United Kingdom. It is collected in all 189 countries that are members of WMO; from the oceans, using climate stations on both buoys and ships, and also with satellites.
“We are in a warming trend—we have no doubt about that,” said Michel Jarraud, secretary-general of WMO, at the Copenhagen briefing today. As some of the U.K. Met Office data comes from the University of East Anglia, embroiled in the ClimateGate scandal, reporters’ questions touched on the validity of that work. Jarraud responded by stressing that the data comes from three independent sources, all of which corroborate the same warming trend and average temperature rise for 2009.
Jarraud said that most parts of most continents showed the warming trend with the exception of the United States and Canada, which were slightly cooler than in previous years. Parts of Asia, Africa, and Australia are likely to have experienced the highest temperatures on record though, he added.
The U.K.’s Met office today said: “These figures highlight that the world continues to see global temperature rise most of which is due to increasing emissions of greenhouse gases into the atmosphere, and clearly shows that the argument that global warming has stopped is flawed.”