From a Stanford University Study as described in Science Daily
Seasonal records
The Stanford team also forecast a dramatic spike in extreme seasonal temperatures during the current decade. Temperatures equaling the hottest season on record from 1951 to 1999 could occur four times between now and 2019 over much of the U.S., according to the researchers.
The 2020s and 2030s could be even hotter, particularly in the American West. From 2030 to 2039, most areas of Utah, Colorado, Arizona and New Mexico could endure at least seven seasons equally as intense as the hottest season ever recorded between 1951 and 1999, the researchers concluded.
"Frankly, I was expecting that we'd see large temperature increases later this century with higher greenhouse gas levels and global warming," Diffenbaugh said. "I did not expect to see anything this large within the next three decades. This was definitely a surprise."
The researchers also determined that the hottest daily temperatures of the year from 1980 to 1999 are likely to occur at least twice as often across much of the U.S. during the decade of the 2030s.
"By the decade of the 2030s, we see persistent, drier conditions over most of the U.S.," Diffenbaugh said. "Not only will the atmosphere heat up from more greenhouse gases, but we also expect changes in the precipitation and soil moisture that are very similar to what we see in hot, dry periods historically. In our results for the U.S., these conditions amplify the effects of rising greenhouse gas concentrations."
Besides harming human health and agriculture, these hot, dry conditions could lead to more droughts and wildfires in the near future, he said. And many of these climate change impacts could occur within the next two decades -- years before the planet is likely to reach the 2-degree C threshold targeted by some governments and climate experts, he added.
"It's up to the policymakers to decide the most appropriate action," Diffenbaugh said. "But our results suggest that limiting global warming to 2 degrees C does not guarantee that there won't be damaging impacts from climate change."
The GRL study was supported by the U.S. Department of Energy and the National Science Foundation. The high-resolution climate model simulations were generated and analyzed at Purdue University. GRL is a publication of the American Geophysical Union.
