Opinion Columns & Blogs

Cold weather does not refute global warming

If you live in the U.S., you have been feeling insanely cold lately. The Weather Channel says that parts of the Midwest and Great Lakes region may experience “one of the longest sub-freezing spells on record for the month of November.” But the whole United States has been quite cold. In Washington, D.C., Tuesday night, a weather emergency was announced due to the expectation of extremely cold temperatures.

We’ve been through this drill before – last winter, actually. And it’s important to keep in mind that just because it is very cold in the U.S. doesn’t mean that you should question the overall warming trend for the planet. Weather shifts heat and cold around – we know that.

Note also that the global temperature anomaly is positive, not negative, and that the Arctic is especially warm, relative to baseline temperatures for 1979-2000.

Indeed, much evidence suggests that we may be experiencing this stark cold while en route to the warmest year in recorded history. Just recently we learned that October 2014 on a global level was the hottest October on record. And the National Oceanic and Atmospheric Administration has shown there is a very good chance of 2014 setting an overall temperature record.

All of that said, pointing this stuff out at the moment may be a losing battle. Despite the fact that weather and climate are not the same thing – climate is the statistical average of weather – extremely cold winters do appear to shift climate beliefs. A recent study by Tatyana Deryugina of the University of Illinois at Urbana-Champaign found that not only do abnormal weather fluctuations greatly affect people’s views of global warming, but that there’s an “asymmetry” here. “Colder days weaken beliefs in global warming much more than warmer days strengthen them,” noted the paper.

But the study also found that the size of the effect depends on how long the cold (or hot) spell lasts. So, keep your hopes up: Not only for a more normal winter to resume soon, but for not too many people to confuse weather and climate change in the meantime.