Despite ongoing discussion that drought is strong indicator of climate change, a federal study released this spring by the National Oceanic and Atmospheric Administration says last year's drought was not instigated by climate change, but by a reduction in moisture coming in from the Gulf of Mexico.
The report authors point to two specific reasons why they believe the drought is not related to climate change: rapid onset and unpredictability.
"The event did not appear to be just a progression or a continuation of the prior year’s record drought event that occurred over the southern Great Plains," the study says, noting that it developed suddenly with near normal previous precipitation during winter and spring. The near normal rainfall gave little forewarning of subsequent failed rains.
Conducted by NOAA's drought task force, the report says the drought could be characterized as a flash drought – an event that appears quickly and yields significant growing-season impacts.
"Neither ocean states nor human-induced climate change, factors that can provide long-lead predictability, appeared to play significant roles in causing severe rainfall deficits over the major corn producing regions of central Great Plains," the report says.
Natural variations in weather, including lack of moist Gulf of Mexico air infrequent summertime thunderstorms were the key causes behind the drought, they note.
Impacts of the drought were extreme, resulting in loss estimates in excess of $12 billion. Specifically, river commerce and agricultural production was halted, leading to long-term impacts.
Though much of the Corn Belt is now seeing a drought reprieve – with short-term weather patterns actually headed the other direction, towards rain and cool temps – the Great Plains is still suffering from lack of moisture.
But, after 2012, NOAA researchers say the drought has done nothing to deter U.S. corn and soybean plantings for 2013. The expected corn acreage, 97.3 million acres, would be the highest since 1936. The expected soybean acreage of 77.1 million acres would be the fourth-highest planted area on record. For 2013, cotton plantings are expected to total 10.0 million acres, down 19% from a year ago.
Click to read the report, An Interpretation of the Origins of the 2012 Central Great Plains Drought.