Pictures such as this set off a good deal of discussion in the blogosphere last week over the connection between Global Warming and big winter storms like the one just winding up outside of my window. Some of this discussion was well-meaning but confused, and some of it quite painfully stupid.
I thought I would pinch from a recent essay by blogger Tamino to help clarify things.
The graph above shows the NA snow cover trend back to the 1970s. Tamino's analysis of it and several similar graphs concludes as follows:
The seasonal pattern of snow cover shows that there’s been no noticeable decline during fall and winter, so we shouldn’t be the least bit surprised by the large snowfall over the U.S. this past week. We can also plainly see that snow cover exhibits extremely large fluctuations, so again last week’s snowfall is no surprise whatever, and no harbinger of any reversal of global warming. But the rapid decline of springtime snow cover over the last four decades, and the even more rapid decline of summer snow cover, show the mark of global warming unambiguously. And despite what some like to shout, the statistically strong trends are what’s important, not the statistically normal noise.
An exceptionally clear, well-written post.