Climate Change Induced Corn-mageddon?
According to a new article at the Guardian, corn-mageddon could be just around the corner in the United States because of anthropogenic climate change:
"The days of 'king corn' could be numbered as climate change brings higher temperatures and water shortages to America's farmland, a new report warned on Wednesday...
The report amplifies warnings earlier this year from United Nations climate scientists and the National Climate Assessment that America's agricultural industry -- and specifically its corn crop -- was at risk from the high temperatures and water shortages anticipated under climate change...
Corn uses the most water for irrigation of any crop, and accounts for half of all fertiliser use. Some of that corn is raised in areas experiencing water shortages because of over-use and recurring droughts, such as California's Central Valley or the high plains states of Kansas and Nebraska...
Recent studies have found corn at high risk from the higher temperatures, changing rainfall patterns, and water shortages caused by climate change. Corn plants are especially sensitive to heatwaves and drought. A report in Science last month found that growers were having more trouble than initially expected in adapting to hotter and drier conditions.
The scientists said growers in the mid-west could lose as much as 15% of their yield within the next 50 years."
There is a lot of alarmism here that needs to be countered.
Droughts in the U.S. corn belt are becoming far less common and severe at a rapid rate. Here is the 60-month major drought index (the PDSI) for the American corn belt since 1895. Negative numbers and yellow bars indicate drought conditions, with more negative numbers signifying more intense droughts. Positive numbers and green bars represent wet (i.e., anti-drought) conditions, with more positive numbers indicating increasingly wet (anti-drought) conditions.
According to NOAA's own data, long-term drought has all but disappeared in the U.S. corn belt, and it is only getting wetter and wetter over time. And yes, that trend towards massively anti-drought conditions in the corn belt is also massively statistically significant.
We find the exact same highly statistically significant trends towards far less drought in the corn belt since the late 1800s when we look at the 48-month, 36-month, 24-month, annual, May-October, or summertime PDSI. It is absurd to suggest that droughts in the American corn belt are becoming more frequent or severe due to climate change. The exact opposite is taking place.
The corn belt as a whole isn't even getting warmer during the main portions of the growing season. There are no significant trends in summertime or May-October average temperatures since 1895 for this region. Annual, May-October, and summertime precipitation in the corn belt all have significant increasing trends since 1895.
All this appears to run completely contrary to the concerns noted in the Guardian's article and the reports it is founded upon.
The Guardian also expresses concern over current and future corn production in California. Corn production in California forms a negligible portion of the American corn crop. In 2013, total planted acres of corn in California only made up 0.6 percent of the US total. Corn for grain production in California during 2013 comprised only 0.2 percent of the nation's output. California could stop producing corn entirely and the United States overall production capacity wouldn't even notice.
Even Kansas contributed only 4.5 percent of the total planted acres in 2013 and 3.7 percent of corn for grain production. Regardless, here is the long-term drought trend in Kansas since 1895.
Just like the corn belt as a whole, long-term severe droughts in Kansas have all but disappeared and there most certainly is no trend since 1895 towards more frequent or severe drought conditions on a 60-month basis, nor on 48-month, 36-month, 24-month, annual, May-October, or summertime bases. Nor are there trends over the past 120 years in May-October or summertime average temperatures for the state. Annual, May-October, and summertime precipitation all show no hint of declining trends.
Moving on to Nebraska, there are no significant trends since 1895 in 60-, 48-, 36-, or 24-month drought indices for the state, nor at the annual, May-October, or summertime intervals, either. Neither are there significant trends for summertime or May-October average temperatures over this time frame, or for annual, May-October, or summertime precipitation.
As for corn yields, here are the national yields headed all the way back to 1866.
The last 11 years have produced the 10 highest national corn yields over this 148-year history. Even the drought year of 2012 provided the 20th highest yield on record. All of the top 20 all-time corn yields have taken place since 1992. Does that seem like indications of an impending climate change induced corn-pocalypse?
Of course, yields of corn must eventually stop increasing due to simple biological and physical limitations. It is simply impossible to yield an infinitely large number of bushels per acre. Unfortunately, when that inherent limit is reached, someone will undoubtedly try to blame the plateau on anthropogenic climate change.
Is the great American climate change induced corn-mageddon looming over the planet? Sure doesn't look like it.