By Patrick J. Michaels, Forbes

Almost every major American daily newspaper picked up an article published earlier this month by New York Times scribe Justin Gillis entitled “A Warming Planet Struggles to Feed Itself.”

How many times have we read, in the last 50 years, that this or that environmental apocalypse is going to starve the world?  I got my doctorate on the wings of one; at that time it was called “global cooling,” after a 1974 CIA report leaked to the Times said that rapidly cooling planetary temperatures could usher in an era of heightened global instability caused by food shortages.

In my lifetime there have been a large number of predicted nutritional apocalypses, caused by overpopulation, lack of biological diversity in our food supply, genetic engineering run amok, acid rain, too little ozone, too much ozone and, finally, global warming.  If there were futures on the end of the world, I’d go short.  The wrong bet won’t matter anyway.

Facts: Global surface temperature rose about three-fourths of a degree Celsius in the 20th century. U.S. corn yields quintupled.  Life expectancy doubled.  People got fat. Global warming didn’t cause all of this, but increased atmospheric carbon dioxide directly stimulated plant growth. Further, greenhouse warming takes place more in the winter, which lengthens growing seasons. With adequate water, plants then fix and yield more carbohydrate.

While doing my dissertation I learned a few things about world crops.  Serial adoption of new technologies produces a nearly constant increase in yields. Greater fertilizer application, improved response to fertilizer, better tractor technology, better tillage practices, old-fashioned genetic selection, and new-fashioned genetic engineering all conspire to raise yields, year after year.

Weather and climate have something to do with yields, too.  Seasonal rainfall can vary a lot from year-to-year. That’s “weather.” If dry years become dry decades (that’s “climate") farmers will switch from corn to grain sorghum, or, where possible, wheat. Breeders and scientists will continue to develop more water-efficient plants and agricultural technologies, such as no-till production.

Adaptation even applies to the home garden. The tomato variety “heat wave” sets fruit at higher temperatures than traditional cultivars.

However, Gillis claims that “[t]he rapid growth in farm output that defined the late 20th century has slowed” because of global warming.

His own figures show this is wrong. The increasing trend in world crop yields from 1960 to 1980 is exactly the same as from 1980 to 2010.  And per capita grain production is rising, not falling.

Gillis more rightly could have blamed any loss in per capita consumption on the stupid (I choose my words carefully) global warming policy that greens once touted: ethanol production from corn.

Even Al Gore now admits that corn-based ethanol produces more carbon dioxide than it saves.  But as a result of recent ethanol policy, we are the first nation in world history to burn up its food supply to please a political faction.

Indur Goklany, a much-published scholar on the consequences of global warming policies, recently calculated that in 2010 alone, diversion of grain to biofuels (like ethanol) caused nearly 200,000 excess deaths in the developing world because of increased prices.

Roger Pielke, Jr., another noteworthy student of global warming science and policy, concurs.  Regarding Gillis’ piece, he says: “The carbon dioxide-centric focus on the article provides a nice illustration of how an obsession with ‘global warming’ can serve to distract attention from factors that actually matter more for issues of human and environmental concern.”

Ever since people noticed how robust the increase of crop yields is, others have been saying that it must soon stop.  This “limits to growth” argument is as tired as a farmer at the end of harvest.  Two weeks ago, it was announced at the Global Wheat Rust Symposium that scientists are now producing “super varieties” of pathogen-resistant grain, which will tack another 15% onto yield.  As the new strain is adopted, it will continue the linear upward trend in wheat yield for at least another decade.

I continue to be amazed at how little the facts are checked on global warming, even when writing for the so-called newspapers of record.  Crop yields have increased at a constant rate despite changes in global temperature.  Per capita grain production is going up, and stupid policies - not global warming - are putting people’s food security at risk.

Patrick J. Michaels is Senior Fellow in Environmental Studies at the Cato Institute and author of Climate Coup: Global Warming’s Invasion of our Government and our Lives.