Climate Change and Corn in North Dakota

Over the past year-and-a-half, the mainstream media has taken note of increasing corn production in North Dakota since the early 2000s. And, of course, climate change is trotted out as the cause (i.e., the supposed warming is leading to more favorable growing conditions), but -- as is far too often the case -- much of the journalism is lacking a complete characterization of what is going on.

We can start with this quote from a story that appeared in The Bismarck Tribune last November: According to studies by North Dakota State Climatologist and North Dakota Agricultural Weather Network Director Adnan Akyuz, the average annual temperature in North Dakota has increased by 0.27 degrees in the last 10 years. Because of the temperature increase, the length of the growing season has increased 17.5 days in the last century. The average annual temperature in North Dakota most certainly has not increased by 0.27 degrees in the last 10 years. The regression between 2003 and 2012 is massively non-significant (p-value=0.9; almost a perfect non-correlation), and from 2004 to 2013 the correlation was actually negative (i.e., cooling) but still highly non-significant. In other words, there has been absolutely no trend in North Dakota's average annual temperature over the past decade. At the Wall Street Journal -- which has been getting progressively wobblier on critical assessments of climate change -- there were also some odd claims regarding North Dakota's temperature trend in an article from mid-2013:

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Warmer temperatures -- which give corn plants more days to mature -- have helped make it more practical to plant the crop in North Dakota. In the past 100 years, the state's average temperature has risen 2.7 degrees, lengthening the growing season by an average 1.2 days per decade, said Adnan Akyuz, the state's climatologist.

This doesn't appear to be accurate, either. According to the NOAA database, the 1913-2012 trend (aka, "the past 100 years") -- remembering that 2013 annual data wasn't available when this WSJ story was written -- in North Dakota's average temperature is only 2.2°F. Akyuz's claimed trend is almost 25 percent higher than the actual trend. And Akyuz's basic math on the length of the growing season doesn't add up. In the first story, we read that "the length of the growing season has increased 17.5 days in the last century" while the second story states that "in the past 100 years, the state's average temperature has risen 2.7 degrees, lengthening the growing season by an average 1.2 days per decade." Multiply 1.2 by ten (i.e., ten decades in 100 years) and you get 12, not 17.5. Who knows what is going on with this apparent 50 percent difference in the rate of change for the growing season during the past century, both sourced from the same individual just a few months apart. But there are also critical details that this over-simplified climate reporting omits. Since the late 1960s, there has been no significant trend in North Dakota's average temperature, and over the past 30 years the correlation has turned negative towards cooling. So, yes, North Dakota is warmer now than it was a century ago, but the past five decades have seen no change in its average temperature, and the past three decades hint at a possible cooling trend. How does this square with anthropogenic climate change supposedly leading to the massive increase in corn production for the state over the past decade? Even the agricultural trade publications can't get the information about corn and North Dakota correct. The Farm and Ranch Guide reported the following last October:

"The corn industry's impact on North Dakota's economy has grown substantially over the past 40 years, in which the state's corn cropland has increased 8 percent."

Rather than just an 8 percent increase in "the state's corn cropland" over the past 40 years, the increase was 562 percent -- from 0.54 million acres in 1973 to 3.6 million acres in 2012. And when we look at the corn area planted in North Dakota each year dating back to 1926, it becomes abundantly clear that climate change has effectively nothing to do with the recent increase. This finding gets reinforced by the fact that changes in average annual temperatures aren't particularly useful for assessing crop production of annual plants such as corn. Growing season average temperatures are a far more useful indicator. The May through November period is the typical growing season for corn in North Dakota. There hasn't been a significant trend in the state's average temperature during the corn growing season over the past century, or since 1970, or over the past 30 years. Even worse for those attempting to put forward the climate change argument as an explanation for North Dakota's recent rapid rise in corn production is the simple fact that growing degree days haven't exhibited any significant trend over the past century for any of the state's climate regions in the NOAA-NWS database -- and no significant trends over the past three decades, either. It seems that every time there is a change in something, it must be due to climate change. A consistent climate change narrative has been spun all throughout the media for many years now, and most of it is entirely incorrect. So what has led to North Dakota's increasing corn acreage since 2002? Money, and advancements in agricultural technology. This is the correct causal link, and the information is out there if you look hard enough for it -- often hidden behind some climate change related babbling. Here are some quotes from the media articles I've cited already that explain what is really going on:

• "advancements in biotechnology and high corn prices are pushing the nation's Corn Belt northward"
• "hardier seeds are enabling farmers to grow corn in areas once deemed inhospitable to the crop"
• "Corn prices are about double historical norms, driven by food demand in China and other fast-growing countries, as well as the rise of U.S. ethanol production. Farmer Steve Fritel planted more corn than wheat for the first time this spring. 'Wheat is profitable; corn is just more profitable,' said the 58-year-old, who farms about 4,000 acres near Rugby with his son Brad."
• "Excluding labor and management costs, farmers here in north-central North Dakota will earn about $126 per acre in profit from corn this year, about double the expected return of $65 an acre for wheat, said Dwight Aakre, an extension economist at North Dakota State University."
• "Corn is a higher grossing crop than either soybeans or wheat. In 2008, corn created $464/acre of cropland, which is $95/acre more than the second highest crop in wheat, and $192/acre more than soybeans."
• "Researchers have developed corn varieties that mature faster and need less moisture, alleviating concern about the region's relatively short growing season and variable precipitation."

Now just remove the climate change related discussions surrounding these quotes in each story and we have a more accurate picture of what is happening with corn production in North Dakota.