The worst case projections for global warming may be the most likely, according to an analysis from scientists at the National Center for Atmospheric Research (NCAR).
The NASA-funded research by NCAR scientists John Fasullo and Kevin Trenberth was published Thursday in the journal Science.
Fasullo and Trenberth analyzed how 16 leading climate models reproduce observed relative humidity, a major influence on global temperatures, focusing on the subtropics.
"There is a striking relationship between how well climate models simulate relative humidity in key areas and how much warming they show in response to increasing carbon dioxide," said Fasullo. "Given how fundamental these processes are to clouds and the overall global climate, our findings indicate that warming is likely to be on the high side of current projections."
The most common benchmark for comparing model projections has shown a range of global warming between 3 degrees F and as high as 8 degrees F by the late 21st century compared to late 19th century.
“Because we have more reliable observations for humidity than for clouds, we can use the humidity patterns that change seasonally to evaluate climate models,” stated Trenberth. “When examining the impact of future increases in heat-trapping gases, we find that the simulations with the best fidelity come from models that produce more warming.”