Using a new program that allows daily worldwide weather to be evaluated, Princeton geoscience professor David Medvigy found that daily weather has grown increasingly erratic and extreme worldwide.
Writing in the Journal of Climate, he and colleagues say that wider fluctuations in sunshine and rainfall are now affecting more than a third of the planet.
Most previous research into climate change has focused on time scales that deal in months, years or decades.
“Monthly averages reflect a misty world that is a little rainy and cloudy every day. That is very different from the weather of our actual world, where some days are very sunny and dry,” Medvigy says.
The study found more frequent incidents of dryness quickly shifting to downpours, and clear skies abruptly becoming cloudy, over the past two decades.
These swings could have significant consequences for agriculture, solar-energy production, ecosystem stability and the control of pests and diseases, the study cautions.