SHELBY SHARES: As planet temperatures rise, Minnesota farmers watch soil vanish

Minnesota farmers have seen an increasing amount of their rich soil washed and blown away in recent years. As the planet gets hotter, and Minnesota gets warmer and wetter, soil erosion is critical problem. But farmers have part of the answer, and it is right outside their windows.
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The Minnesota Farmers Union gathered at the Arrowwood Resort in Alexandria to talk about agriculture last week. I was an invited speaker, but I also did a lot of listening.

Commodity and land prices are changing rural America, and nowhere is it more apparent than in Minnesota. But farmers around the world are facing a threat to their livelihoods, and to the globe’s ability to feed itself. Soil is disappearing.

That’s a serious problem because more than 99 percent of the food we eat comes from the soil. It is disappearing at a rate as much as 40 times faster than it can be replenished naturally.

It is disappearing because of erosion, by wind and water. It is drying out because the temperatures are increasing. David Pimentel, a professor of ecology at Cornell University, says soil erosion is the second-largest problem the world faces after population growth. He puts it bluntly when he says that a chunk of land the size of Indiana is rendered unproductive each year.

Europe calculates it differently. Based on research by Jared Diamond at UCLA, topsoil loss around the world is calculated to be near 25 million acres per year. One estimate suggests that a body of land 10 times the size of the United Kingdom can no longer produce food on it. That shocking finding was part of a report issued in November by the United Nations.

Minnesota farmers love the land but have been watching it being washed and blown away in increasing quantities in the last 20 years. There is a reason for that, scientists say.

No one disputes that the planet is warming. The increased temperatures cause landmasses, more than oceans, to give up more moisture to the atmosphere. Evapotranspiration is the technical term. The hydrological cycle is a closed loop. All the water that was ever here is still here. So where does the water from the land go? It ends up in the atmosphere as water vapor.

According to Kevin Trenberth, a lead scientist at the National Center for Atmospheric Research, as a result of warmer temperatures, there is about 4 percent more water vapor in the atmosphere. What goes up must come down. And climatologists have been warning for the last 30 years that when the water returns to earth as precipitation, it will come down as a deluge. All a farmer can do is watch his or her topsoil run off into the nearest drainage ditch.

The farmers gathered in Alexandria read the papers and listen to the radio news. They know that a recent national research project found Minnesota is heating up rapidly. BringMeThe News reported the story. Only two other states (Arizona and Michigan) are warming faster than Minnesota. Minnesotans do not want to be at the top of this list. Climatologists have been warning that Minnesota is going to get warmer and wetter in the coming decades. That is exactly the formula for soil erosion, and the farmers take it all very seriously.

The good news is while farmers face a dilemma, they also have part of the answer to turning the temperature problem around, and it is right outside their windows. Wind-generated electricity on their property, methane digesters for manure providing their natural gas needs, biofuel crops in the fields. There are predictions that farmers, who are heavily reliant on fossil diesel fuel, coal-generated electricity and natural gas heating, will grow and use their own renewable fuels to operate their farms. Less CO2 means less warming. Less warming means less flooding. Less flooding means less soil erosion and nutrient loss.

It sounds like an awfully large burden to place on the backs of farmers. But everyone knows that when you need some heavy lifting done, you go find a farmer to give you a hand.

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