environmentalresearchweb.org, December 3, 2010
“We're finding that the length of the heat waves gets to the point where it almost becomes the norm in model situations towards the end of the 21st century,” Easterling explained. “In a lot of places the temperatures warm up to that point just about every day.”
Going to extremes
Going to extremes
These interim results from Easterling's latest research typify his keen interest in extreme climate events. Given the high profile of such phenomena, he is used to fielding questions about whether climate change has caused an individual event.
While the stock answer is: “no, but it increases the chances,” he wants to try to pin down more direct relationships. “We want to be a little more specific and ask 'Can we say anything about the heat waves in Russia?,' for example,” Easterling told environmentalresearchweb.
A group at the NCDC's parent organisation, the US National Oceanographic and Atmospheric Administration (NOAA) is helping address this question. The researchers use models to study an event and look for signals to indicate that climate change has raised the temperature during a heat wave. “It's a tough nut to crack,” Easterling admitted. “You have to use both observations and model simulations to see how much of that heat wave was due to climate change rather than just chance or circulation of the atmosphere.”
Easterling's expertise in extreme events has led to him being chosen to work on a special report on climate extremes for the Intergovernmental Panel on Climate Change (IPCC) that is due out in 2011. The division that the climatologist leads is largely responsible for the continuous flow of temperature data documenting global warming's progress. On that basis he has also been selected as a lead author of the chapter on surface and atmospheric observations for the IPCC's fifth assessment report.
Yet as debate about climate change rumbles on in some quarters, NCDC's measurements have increasingly come under attack. Easterling hopes that another of his ongoing projects – documenting from start to finish exactly what the team does to produce global temperatures – will disarm some of these objections. He notes that some blogs have accused NCDC of removing stations at high latitudes and altitudes to exaggerate the evidence for warming.
“That is actually an interesting hypothesis, because we've seen the greatest warming in the high latitudes, and we want more stations up there, we want more data to be able to document it,” Easterling countered. “People think that we're removing stations, where the reality is the countries are simply not sending the data out – they do it sporadically, as opposed to on a regular basis.”