The climate outside the window

I felt a little guilty driving into work today with the air conditioning on in the car, with the thought that I’m living through the last days of a planet. But weather is not climate… except when it is, I found out this afternoon.

Today, the Bad Astronomy blog asks, “when does weather become climate?” And then answers, “now.”

Is all this due to global warming? Hard to say, exactly. However, these conditions are precisely what you would expect as the Earth warms: weather patterns change, temperature records get broken, conditions go from normally wet to dry, normally dry to wet.

“Weather” is what you look at if you want to know if you need an umbrella or not today. “Climate” is what you expect on average for a given day in a given place. Weather changes on short time scales; climate over long ones. But how long?

Weather + time = climate. It’s well past time to start thinking of that “time” as now.

NASA, too, jumps into the “it’s climate!” declaration in explaining the latest land temperature analysis in the United States, which shows it’s overwhelmingly hot.

This heat wave, like all extreme weather events, has its direct cause in a complex set of atmospheric conditions that produce short-term weather. However, weather occurs within the broader context of the climate, and there’s a high level of agreement among scientists that global warming has made it more likely that heat waves of this magnitude will occur.


  • BJ
  • Time to die?

  • John O.

    I am curious about one aspect of this debate.

    How does one differentiate the current weather and/or climate from, say, the “Dust Bowl” of 1930’s? To what extent can the two be compared?

  • BJ

    @John O. I am no expert, but from my limited understanding the dust bowl of the 1930’s was a regional thing – as opposed to global. And was partly caused from farming practice’s. Plowing under of grasslands that held the soil in place, for example.

  • Craig

    in july 1936 the average high temperature in Farmington, MN was 95.2 degrees. They recorded 12 days when the temperature reached 100 degrees or greater. From June 24 to June 30 the high temperature records for the Twin Cities occurred in either 1931 or 1934. Quite a few record highs for July in the Twin Cities occurred in 1936.