Scientists say the heat wave at the end of June in the Pacific Northwest was a truly extraordinary event. Temperature records were broken by as much as 9 degrees, which is unheard of.
That has some scientists wondering if it is a sign that something different is at work. Perhaps, they say, the world has warmed to a point where just a little additional warming can cause a huge jump in extreme heat. They will study it more, but if that’s the case, even more severe heat waves may be in the offing.