Dust Climate Indicator

Guarding against future “Dust Bowl”

National Climate Assessment (NCA)

Background:

During the Great Depression, the United States experienced one of the worst environmental catastrophes, the Dust Bowl in 1930s. An extended drought, coupled with high winds and poor land management, led to numerous large dust storms in the Central Plains. These storms striped farms of topsoil, buried houses, and forced millions to migrate to cities and the West Coast. Will we see another Dust Bowl in our lifetime?

Our research team, which includes scientists with George Mason University, University of Texas, NASA, National Oceanic and Atmospheric Administration (NOAA), and US Department of Agriculture (USDA), has recently been supported by NASA and other federal agencies to develop a new climate indicator to answer this question.

Although the severity of the 1930s drought was exceptional, climate models have robustly predicted even more extreme drought conditions in the coming decades. It has been argued that precipitation shift, greater evaporation, less snow/ice and earlier spring, all powered by warming, will amplify the effects of natural climatic variations (e.g., the El Niño-La Niña cycle). As a result, intensified seasonal or decade-long droughts can lead to “dust-bowlification” rather than “desertification” in the Americas.

Figure 1. Buried machinery in barn lot in Dallas, South Dakota during the Dust Bowl (USDA).

There are multiple lines of evidence suggesting that the western United States has already become dustier in the past decades. Regardless of decreased anthropogenic aerosol emissions, soil dust in rainwater and snow deposition is on the rise. This upturning trend is a reversal to the decline reported in 1980s. Meanwhile, the Center for Diseases Control and Prevention (CDC) has reported a sharp increase in valley fever (Coccidioidomycosis), an infection caused by inhalation of a soil-dwelling fungus. The incidence rate of valley fever has increased by eight-fold from 1998 in 2011 in the regions frequented by dust storms.

This new NASA project has an ambitious goal to build a broad consensus of the dust trends, so that a baseline can be developed to watch for future dust anomaly. The scientists will use satellite sensors, ground monitors, and computer models to reveal not only the long-term trend, but also the climate forces behind it. The team, the GMU Center for Spatial Information Science and System, includes dust scientists from University of Texas, NASA, National Oceanic and Atmospheric Administration (NOAA) and US Department of Agriculture (USDA).

This research is expected to provide important information for climate adaptation for a variety of user communities, including agriculture and soil conservation, air quality, public health, transportation and real estate investment in the impacted sectors. This project will initially focus on supporting the USDA and the soil conservation community, as USDA is the nation’s leading force to combat and mitigate climate-related soil erosion. In the U.S., the loss of topsoil has been estimated to cost $125B per year.