Climate uncertainties and the problems communicating them

[n2doc]

By John Timmer | Last updated January 24, 2010 5:45 PM

One of the aspects of science communications that can frustrate even its most sophisticated practitioners is the ability of scientists to reach confident conclusions about the big picture even when a field retains significant uncertainties. You can look no further than dark matter for an example: researchers are pretty confident that it's out there, even though we still haven't identified what it might consist of. But climatology remains the field where uncertainties, both real and imagined, are most likely to become front page news. The journal Nature has devoted a series of articles to discussing why that's likely to be the case.

The editorial staff assigned one of their senior reporters to identifying the areas of most significant uncertainty when it comes to climatology and, as that reporter noted, the primary challenge is whittling things down: the most recent IPCC report identified 54 items that it termed "key uncertainties." Contrary to some accusations, this suggests that the areas where climate science needs some work haven't exactly been swept under the rug by the scientific community. But, at the same time, scientists have clearly looked at these uncertainties and decided that they're not so significant that the basics of climate change are questionable.

One of these areas is actually a relatively well known controversy: millennial-scale reconstructions—the famed hockey stick, which shows that temperatures have risen dramatically in the past century. Anybody who has paid careful attention to the "hide the decline" e-mails knows that tree ring indicators of past temperatures have tracked the instrument record until the 1960's, after which subarctic trees diverge.

In this case, there's even uncertainty about the significance of the uncertainty. As the article notes, some argue that we shouldn't put much weight on any tree ring data until we can understand the cause of the divergence. Others suggest that the presence of a hockey stick in non-arboreal data and the continued high temperatures (NASA data places 2009 as the second warmest year on record) mean that the general conclusions are solid.

more:

http://arstechnica.com/science/news/2010/01/climate-uncertainties-and-the-problems-communicating-them.ars