Weather is what’s happening in the air around us, and climate is how it is, long term, where we are. At least, that’s what we used to mean, back when a location came with a climate: temperate, tropical, sunny, or moist. Seasonal variations were part of the idea of climate – summer, winter, monsoon, mistral – but there was little room for other change within the concept. On the other hand, the weather changes constantly, giving us a way to make conversation in elevators with total strangers or romantic rivals.
At the end of the nineteenth century, Arhennius pointed out that man-made variations in the carbon dioxide content of the atmosphere could alter the earth’s temperature, and the science of climate change was born. A fringe activity until around 1990, it now attracts most of the attention of atmospheric scientists, since it is well established that if we continue our wasteful ways we will irretrievably alter the earth’s climate, and not in a good way.
But all this talk of climate change is about long term statistical quantities, like average temperature, area of minimum arctic sea ice, fraction of coral reefs bleached past recovery, or the range of altitudes over which the edelweiss can flower. Ask a climate scientist about the severity of the rainstorm last Sunday night and she will suggest that you talk to a weather analyst, since no individual weather event can be directly tied to the slow process of climate change.
Well, for any individual event, that’s probably true. But have you been following the news lately? Bill McKibben, the founder of 350.org, has, and in an astonishing op-ed piece published in the Washington Post he implicitly challenges climate scientists to deal not with individual weather events, but with the extraordinary series of floods, tornadoes, and everything but a rain of frogs that have been devastating one locality after another. I won’t tell you his conclusion because everyone should read the entire piece for themselves. Less time than you’ve already put in, guaranteed!
Photo credit: NASA