The floods battered New England, then Nashville, then Arkansas, then Oklahoma — and were followed by a deluge in Pakistan that has upended the lives of 20 million people. The summer’s heat waves baked the eastern United States, parts of Africa and eastern Asia, and above all Russia, which lost millions of acres of wheat and thousands of lives in a drought worse than any other in the historical record.
Seemingly disconnected, these far-flung disasters are reviving the question of whether global warming is causing more weather extremes.
The collective answer of the scientific community can be boiled down to a single word: probably. “The climate is changing,” said Jay Lawrimore, chief of climate analysis at the National Climatic Data Center in Asheville, NC. He described excessive heat, in particular, as “consistent with our understanding of how the climate responds to increasing greenhouse gases.”
Theory suggests that the world is warming up because of the gases will feature heavier rainstorms in summer, bigger snowstorms in winter, more intense droughts in at least some places and more record-breaking heat waves. Scientists and government reports say the statistical evidence shows that much of this is starting to happen.
The warming has moved in fits and starts, and the cumulative increase may sound modest. But it is an average over the entire planet, representing an immense amount of added heat, and is only the beginning of a trend that most experts believe will worsen substantially. NYT