In his 1989 classic, The End of Nature , ecologist Bill McKibben talks about people’s expectations that spring will come the way it always has come. There may, of course, be cold springs and warm springs, wet springs and dry springs, but what if our deeper expectations are unmet? What if spring is so cold or so warm that it becomes a different season altogether? And what happens, McKibben asks, if our certainty about the predictable sequence of nature falters? People ask me whether I have seen