Heat Wave 2012 - What's Behind It?
August 5, 2012

Is Climate Change Responsible For Record-Breaking June Heat?

redOrbit Staff & Wire Reports - Your Universe Online

More than half of the contiguous states in the US were experiencing drought by early July 2012, and over 170 all-time American heat records were tied or surpassed during the month of June, according to new research released by NASA scientists on Friday.

Many of the record highs experienced during the sixth month of the year surpassed records originally set during the months of July and August, which historically have been hotter than June, Dauna Coulter reported in an August 3 piece entitled "The Summer of 2012 -- Too Hot to Handle?".

Furthermore, she said that the percentage of states experiencing drought was the highest ever recorded in the 12-year history of the US Drought Monitor, and more than 1.3 million acres of American land had been "scorched" by fires in June. Coulter said that the mild winter of 2011 is partly to blame for the scorching summer of 2012.

"799 daytime heat records were broken in the first five days of January in the US," NOAA National Climatic Data Center (NDCD) climate scientist Jake Crouch said. "Last year's was the fourth warmest winter since 1895. And it was dry, with a dearth of snowfall in many places. During most of this past winter and spring, a positive North Atlantic Oscillation pressure pattern kept the jet stream further north and the US warmer and drier than normal."

Naturally, greenhouse gases and global warming are at the core of the issue. NASA climatologist Bill Patzert told Coulter that carbon dioxide levels have increased 43% since the 19th century, and that Americans are emitting six times as much carbon from fossil fuel as they were half a decade ago. In fact, he says that CO2 levels are at their highest levels in more than 400,000 years, and that this (and methane) is responsible for causing Earth's atmosphere to retain more heat than other gases.

"The atmosphere becomes a heat source itself, radiating heat back onto the Earth. 85 to 90% of that heat is absorbed by the oceans, because water has a high heat capacity," Patzert said. "So the oceans expand and rise. Global sea levels have risen 8 inches over the past 130 years, and the average surface temperature of the entire earth has increased 1.6 °F. These facts are unequivocal proof of global warming."

However, he notes that those findings are "not necessarily" evidence of global climate change, adding, "We've always had extreme weather. US history is written in great natural calamities -- tornadoes, hurricanes, heat waves, droughts, floods. Global warming is happening, but it would be irresponsible to say that this heat wave and all these broken records are due to global warming from human causes. It's just not that simple."