Wednesday, November 25, 2009


From Der Spiegel:
Global warming appears to have stalled. Climatologists are puzzled as to why average global temperatures have stopped rising over the last 10 years. Some attribute the trend to a lack of sunspots, while others explain it through ocean currents.

At least the weather in Copenhagen is likely to be cooperating. The Danish Meteorological Institute predicts that temperatures in December, when the city will host the United Nations Climate Change Conference, will be one degree above the long-term average.

Otherwise, however, not much is happening with global warming at the moment. The Earth's average temperatures have stopped climbing since the beginning of the millennium, and it even looks as though global warming could come to a standstill this year.

Ironically, climate change appears to have stalled in the run-up to the upcoming world summit in the Danish capital, where thousands of politicians, bureaucrats, scientists, business leaders and environmental activists plan to negotiate a reduction in greenhouse gas emissions. Billions of euros are at stake in the negotiations.

The planet's temperature curve rose sharply for almost 30 years, as global temperatures increased by an average of 0.7 degrees Celsius (1.25 degrees Fahrenheit) from the 1970s to the late 1990s. "At present, however, the warming is taking a break," confirms meteorologist Mojib Latif of the Leibniz Institute of Marine Sciences in the northern German city of Kiel. Latif, one of Germany's best-known climatologists, says that the temperature curve has reached a plateau. "There can be no argument about that," he says. "We have to face that fact."

Even though the temperature standstill probably has no effect on the long-term warming trend, it does raise doubts about the predictive value of climate models, and it is also a political issue. For months, climate change skeptics have been gloating over the findings on their Internet forums. This has prompted many a climatologist to treat the temperature data in public with a sense of shame, thereby damaging their own credibility.

"It cannot be denied that this is one of the hottest issues in the scientific community," says Jochem Marotzke, director of the Max Planck Institute for Meteorology in Hamburg. "We don't really know why this stagnation is taking place at this point."

Just a few weeks ago, Britain's Hadley Centre for Climate Prediction and Research added more fuel to the fire with its latest calculations of global average temperatures. According to the Hadley figures, the world grew warmer by 0.07 degrees Celsius from 1999 to 2008 and not by the 0.2 degrees Celsius assumed by the United Nations Intergovernmental Panel on Climate Change. And, say the British experts, when their figure is adjusted for two naturally occurring climate phenomena, El Niño and La Niña, the resulting temperature trend is reduced to 0.0 degrees Celsius -- in other words, a standstill.

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