Heat waves, record high temperatures could be norm in U.S. by 2039

Heat waves and extremely high temperatures could become commonplace in the United States in the 30 years, according to a new study.

Stanford University climate scientists say that experiments using two dozen different climate models suggest that America’s going to get hotter more frequently, threatening both the agriculture industry and our very existence.

Writing in the journal Geophysical Research Letters, professor Noah Diffenbaugh concluded that the heat waves could stress vital crops such as corn, soybeans, cotton and wine grapes, leaving reduced yields.

A recent NASA report hinted at the same thing, concluding that the last 10 years, from January 2000 to December 2009, was the warmest on record.

In the study, researchers projected what could happen in the U.S. if increased carbon dioxide emissions raised the Earth’s temperature by 1.8 degrees Fahrenheit (or approx. 1 degree Celsius) between 2010 and 2039.

A few points about such a scenario:

• The mean global temperature in 30 years would be 3.6°F (or 2°C) hotter than observed in the preindustrial era of the mid-1800s.
• It’s well within reason, according to the International Panel on Climate Change. Climate scientists and policymakers have targeted a temperature increase of double that as the maximum threshold before significant environmental damage occurs.

But the researchers’ conclusions indicate that a 2°C threshold may be too high to avoid adverse conditions.

Analyzing temperature data for the continental United States from 1951 to 1999, the researchers recorded the longest heat waves and hottest seasons on record in the second half of the 20th century, then fed them into their many climate forecasting models, including one high-resolution model called the RegCM3.

The results of their projections:

• An intense heat wave is likely to occur as many as five times between 2020 and 2029 in the U.S., specifically in the western and central part of the country.
• The 2030s were projected to be even hotter.
• A dramatic spike in extreme seasonal temperatures were forecast during the current decade. In other words, record highs and lows were forecast to recur more regularly.
• From 2030 to 2039, most areas of Utah, Colorado, Arizona and New Mexico could endure at least seven seasons as intense as the hottest season on record between 1951 to 1999.
• In the 2030s, the hottest daily temperatures of the year between 1980 to 1999 are likely to occur at least twice as often across most of the United States.

But pure temperature isn’t the problem — it’s humidity, too. By the 2030s, the researchers say most of the U.S. will endure “persistent, drier conditions” as a result of more greenhouse gases in the atmosphere.

As residents of the southwestern U.S. can attest, that means more droughts and wildfires.

“It’s up to the policymakers to decide the most appropriate action,” Diffenbaugh said in a statement. “But our results suggest that limiting global warming to 2 degrees Celsius does not guarantee that there won’t be damaging impacts from climate change.”

The study is the product of two years of research and is co-authored by Oak Ridge National Laboratory researcher Moetasim Ashfaq. It was funded by the U.S. Department of Energy and the National Science Foundation.

Photo: Detail of “Resistance.” iDip/Flickr