Climate Change

Share |

Droughts and Heat Waves

August 17, 2011; 9:41 AM ET

The extreme drought across the southern U.S. Plains has certainly exasperated the intense heat the that has persisted through the summer. Did climate change play any role?

There is just not enough data to say for certain that climate change played a role in the unusual heat and drought across parts of the U.S. this year, but it is likely that it had a hand in it.

Scientists and computer models have consistently shown that as we continue to see an increase in greenhouse gases into the atmosphere the number of extreme heat waves will continue to grow. It has also been shown that severe drought will become more common in certain regions of the world.

Compare the two NASA images below. The first one shows where the worst drought conditions were over the U.S. in July. The brown areas indicate where there is much less green vegetation compared to normal. Green areas indicate where there was more green vegetation compared to normal.

The second image shows were the hottest temperatures compared to normal were located during the peak of the July heat wave. As you can see, the driest areas compared to normal are pretty much where the highest temperature anomalies are.

With little or no moisture in the ground, the drought acts as a positive feedback to the heat since the sun's energy can go almost 100% directly to heating the ground instead of initially having to evaporate water from the ground (normal situation), which has a cooling effect.

Also keep in mind, with less vegetation there is also a reduction in evaporation.

-----------

Speaking of July......

According to NOAA, July 2011 was the 7th warmest July on record for land/sea combined going back to 1880.

Here is an updated graph of all the July temperature anomalies going back to 1880 from NOAA.

The views expressed are those of the author and not necessarily those of AccuWeather, Inc. or AccuWeather.com

Comments

Comments left here should adhere to the AccuWeather.com Community Guidelines. Profanity, personal attacks, and spam will not be tolerated.

More Climate Change

  • Clouds are trending higher into the atmosphere

    July 11, 2016; 3:36 PM ET

    New research from the Scripps Institution of Oceanography at the University of California (San Diego) confirms what computer modeling had earlier predicted in regards to the impact of climate change on clouds and mid-latitude storm tracks.

About This Blog

Climate Change
In the AccuWeather.com Climate Change Blog, you will find links to the latest research, commentary by experts with various points of view on all aspects of global climate change.