Research Highlights

Nature Reports Climate Change
Published online: 23 October 2008 | doi:10.1038/climate.2008.112

Riddle resolved

Olive Heffernan

Int. J. Climatol. doi:10.1002/joc.1756 (2008)

NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION

Until recently, data from satellites and weather balloons have shown less warming in the tropical lower atmosphere than on the land and ocean surface, a result inconsistent with model simulations and basic theory, and also at odds with the massive body of evidence on human-induced climate change. But this enduring conundrum in climate science has now been resolved.

A large consortium of scientists led by Benjamin Santer of the Lawrence Livermore National Laboratory in California set out to test a claim by David Douglass of the University of Rochester, New York, and colleagues that 'models and observations disagree to a statistically significant extent' on the issue of tropical warming. Bringing a variety of independent observational data sets and state-of-the-art climate models to the task, they found that the earlier study, also published in the International Journal of Climatology, reached an incorrect conclusion owing to the use of a flawed statistical test and older observational data.

Santer and colleagues were able to reconcile temperature trends in the models with observations by using more appropriate statistical tests, new satellite and weather-balloon data that show greater warming of the tropical lower atmosphere, and improved satellite and buoy data that yielded slightly lower estimates of surface warming.