The USDA updates its national climate change assessment every four years with the next due to be finalized later this year after public comment.

While the broad acceptance that base climate change is occurring has become general and not very controversial, the degree to which the change occurring is natural or recently man-made has divided along mostly political lines rather than science.

The science viewpoint is heavily weighted toward the primary triggering contribution coming from human activity on the planet. A recent study of 11,000 years of world temperatures showed that they made a dramatic U-turn as man-accelerated, green-house gas emissions 250 years ago.

Natural cycles suggested that the world was ready for a turn to more volatile weather anyway so not all of the floods, droughts, and other extreme weather phenomenon occurring are attributable entirely to global climate change, but the science is pretty much unrefutable at this point that it is contributing to the natural cycle.

The recent Penn State University study showed that the world was actually ready for a turn toward a cooler trend when man caused a hockey stick change to a warmer climate.

The USDA is trying to ascertain what this means toward crop production. Using the warmer model, the USDA said the growing season will lengthen by 20 to 40 days by the end of the century and the number of frost days will be reduced in much of the U.S.

This will impact a number of things including the lifecycle of crop pests.

A phone call received by a Canadian subscriber last year asked if one could harvest corn with a grain platform. He went on to explain that they always plant 60 acres of corn as fall grazing for cattle.

This year, however, the corn looked so good he thought it would yield 150 bushels per acre and would be worth combining; but no one near him had a corn head. Combines are used to harvest wheat, barley and oats.

My thought was that this was a sign of climate change. Dr. Elwynn Taylor, Iowa State University’s climatologist, recently said, “Climate change is having some impact on the growing season lengthening growing days further north.

“Minnesota corn yields are increasing at 12.5 percent of the U.S. trendline. They are growing more corn in Canada.

“I was told by a Monsanto research Ph.d. that they are putting a new test farm in Manitoba working on 85-day corn. They are focusing more of their research to grow corn in the NCB and Canada.”

Taylor said that climate change is favoring farms north of U.S. Highway 3 and west of I-35.

USDA went on in its climate assessment, “We’re obviously worried about higher temperatures and their effects on cropping systems, moisture. But there are a variety of implications.

“Especially over the next 20 to 30 years, there will be a mix of consequences for agriculture. One is we expect longer growing seasons. For some crops, ranges within the United States will expand. Also, the effects on rainfall won’t be evenly distributed across the country. Some regions will see an increase in rainfall and moisture availability.”

Concerning livestock the climate report said the effects are a function of temperature.

“Again, you see two types of impacts,” the report said. “One is the negative effects of low winter temperatures. In the summer, there will be greater heat stress and with that comes with losses in production and sometimes mortality.”

I have never been one to believe that the politics would be overcome to bring about the global consensus necessary to do the painful things required to eliminate the human contribution to climate change, so the focus was going to have to be put on adaptation and mitigation.

Things like selling Canadians corn heads as they contribute to corn production are easy fixes. Adapting corn hybrids so they can continue to grow corn in the extreme southern heat is a less favorable change.

How hard we try to reduce greenhouse gas emissions is up to consensus of the public, but adaptation will be forced on us.

The political impasse is evidenced by Republicans appointing chairman of the house science committee members who supplant science reasoning with ideology.

That includes their opposition to biofuel.

David Kruse is president of CommStock Investments Inc., author and producer of The CommStock Report, an ag commentary and market analysis available daily by radio and by subscription on DTN/FarmDayta and the Internet.