Scientists believe major contributors to anthropogenic global warming like burning coal and oil are making the whole planet more humid:
Scientists expect the rising humidity to cause heavier rains, stronger hurricanes, and increased human heat stress.
Climate scientists have long predicted that a warmer world will allow more water to evaporate, thus making the planet more humid.
Indeed, several studies have shown trends of increasing surface humidity around the planet, but until now scientists were uncertain what was driving the trend.
The new study combined a fresh data set of surface humidity with climate models, "and actually attribute[s] those trends to human influence," said study co-author Nathan Gillett, a climate scientist at the University of East Anglia in Norwich, England. (Related news: "Global Warming "Very Likely" Caused by Humans, World Climate Experts Say" [February 2, 2007].)