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Is Another Dust Bowl in Our Future?

by LuAnn Rolling, District Conservationist

In Northeast Iowa we have been blessed with timely rain this summer, but a large portion of the United States has not been so lucky. According to a recent article in Mother Jones rising temperatures and worsening droughts caused by global warming are making some scientists ask if we are headed for another Dust Bowl. The article shares some developments that climate “experts” say are pointing to that scenario:

• In a 2018 National Climate Assessment, U.S. scientists warned that under current warming scenarios, temperatures in the southern Great Plains could increase by 3.6 to 5.1 F by 2050, compared to the 1976-2005 average. The region is projected to be hit by dozens more days with temperatures above 100 F.

• The Ogallala Aquifer - which makes up most of the High Plains Aquifer System and supplies the water for 30-46% of irrigated land in some Great Plains states - has been steadily overdrawn in recent decades. Some estimates show the aquifer could be 70% depleted within 50 years. Mother Jones reported that during the 3-year period between 2011 and 2013, the aquifer lost nearly as much water as it did between 1980 and 1995.

Data shows that both drought and heat are becoming more common - and perhaps increasing the feedback effects between them. In a recent study in Nature, researchers found that greenhouse gas emissions have made a period of Dust Bowl-like heatwaves more than two-and-a-half times more likely compared to the 1930s.

When the soil contains a lot of moisture, incoming energy from the sun gets absorbed by the water as it turns from a liquid into a gas. But when the soil contains little water, that energy is converted directly into heat. The result is that droughts lead to more severe heatwaves, and those heatwaves in turn lead to drier conditions.

Ben Cook, a climate scientist at the NASA Goddard Institute for Space Studies, says the same goes for drought. “What we’re seeing in a lot of regions is this kind of amplified evaporation effect that’s making it easier to get into drought, a little bit harder to get out of drought, and making the droughts themselves a bit more intense than they would have been in a colder world.”

According to the Fourth National Climate Assessment, Volume II: Impacts, Risks and Adaptation in the United States, rising temperatures, extreme heat, drought, wildfire on rangelands, and heavy downpours are expected to increasingly disrupt agricultural productivity in the United States. This Climate Assessment says increases in temperatures during the growing season in the Midwest are projected to be the largest contributing factor to declines in the productivity of U.S. agriculture.

Numerous adaptation strategies are available to cope with adverse impacts of climate variability and change on agricultural production. These include altering what is produced, modifying the inputs used for production, adopting new technologies, and adjusting management strategies. These strategies include fairly common practices, such as no-till, cover crops and crop rotations that include small grains and forages.

There is some progress in adapting these technologies. No-till wasn’t around as a practice during the 1930s, but today the U.S. has more than 100 million acres of no-till. Cover crop acres have more than doubled in the last 5 years to 15 million, the 2017 Census of Ag shows. Every producer can contribute, either positively or negatively, to the effects their practices have on climate change. We can all work together to try to avoid another dust bowl.