Is July 2010 Heat Wave a Sign of Global Warming?

Updated 8/15/10July 2010 was the second warmest on record, according to a new NOAA report.

While July didn’t quite break the record, the first half of the year did. It was the hottest January to June since record-keeping began in 1880.

Is the extreme heat a sign of global warming?

Probably — at least in part — but it is not something that can be proved because short-term weather patterns are highly variable. In other words, near-record highs and near-record lows are the norm.

What’s not normal is that in the last decade, record highs occurred twice as often as record lows in the continental U.S., which shows a warming trend, as this National Center for Atmospheric Research video explains.

So, while the July record does not prove anything in itself, it contributes to the already overwhelming evidence that global warming is underway.

Another thing July 2010 did was show people living in hard-hit areas what global warming will increasingly feel like. For example, New York City, where I live, had 16 days over 90 degrees in July (the second most on record) and another 6 days over 90 in the following two weeks, for a total of 22 days with temperatures over 90 as of August 14th.

UCS's page showing projections for NYC
The NYC page on the Union of Concerned Scientists’ Climate Choices website

Compare this total to global warming projections for New York City by the Union of Concerned Scientists: an average of 23 days over 90 by 2039. That’s just one day more than we’ve had this year, and it’s still only mid-August.

While it will be some years before blistering heat like this becomes par for the course in New York and the many other parts of the U.S. and world that have been experiencing unusual heat waves, the summer of 2010 is a taste — and evidence — of things to come.


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One Response to Is July 2010 Heat Wave a Sign of Global Warming?

  1. Sid August 21, 2010 at 5:40 am #

    I’m still amused that we make huge assumptions based on 130 years of empirical data (which is somewhat accurate) when we know the planet has gone through huge climate swings over the course of 4 billion years.

    I’m not a global warming denier. But I am old enough to remember when in the 1970’s people were worried about global cooling. 40 years before the U.S. suffered droughts and temperatures that led to the dustbowl. A little over a hundred years before that Europe was in a mini-ice age.

    And we know that there were ice ages and very hot periods on and on before that.