Monday, July 1, 2013

Why Climate Change Is Invisible

It rained every day last week. The forecast page was a parade of lightning bolts, and every afternoon rush hour brought a new severe thunderstorm. By Friday I was asking, “This weather isn’t normal, is it?”

It was not even a reasonable question. By then (I found out when I looked it up) we had already seen a summer’s worth of rain, and most of the region had reached new records for June precipitation. I had asked the question only because I had gotten used to the severe weather pattern.

George Will made this mistake when he famously dismissed a Chicago heat wave that had already set new records for weather and deaths. Will was not being malevolent in his comments. He had just made the mistake of using his expectations as a barometer. His expectations were not as fixed as he had imagined, but had already adapted to the changing patterns.

Expectations adapt to changes faster than we could ever imagine. I made this same mistake myself as I lived through an extreme, record-setting weather pattern while imagining it to be an approximation of normal.

We cannot expect our casual observation to inform us of a global average temperature increase of 4 or 5 kelvins over a span of three lifetimes when the temperature increases that much during the course of a normal morning. It will take careful record keeping and observation of physical changes, such as the disappearance of permafrost and flooding on coastlines, to tell us of the extent of the change. It is the physical changes in particular that will tell the story. The melted shoes and canceled flights during the current heat wave in the opposite corner of the country are somehow more persuasive than the numbers are.