dramatic sunset over drought land

The U.S. Environmental Protection Agency (EPA) brought back its Climate Change Indicator’s platform last week. The agency’s post, titled “Climate Change Indicators: Drought,” shows there is no cause for alarm that climate change is increasing drought. The data cited and graphed by EPA shows no trend towards greater numbers of droughts or droughts of greater severity. They say,

“Average drought conditions across the nation have varied over time,” writes EPA. “The 1930s and 1950s saw the most widespread droughts, while the last 50 years have generally been wetter than average [see the figure below]. Over the entire period … the overall trend has been toward wetter conditions.”

This chart shows annual values of the Palmer Drought Severity Index, averaged over the entire area of the contiguous 48 states. Positive values represent wetter-than-average conditions, while negative values represent drier-than-average conditions. A value between -2 and -3 indicates moderate drought, -3 to -4 is severe drought, and -4 or below indicates extreme drought. The thicker line is a nine-year weighted average. Data source: NOAA, 20217 Web update: April 2021

EPA’s drought climate change indicator confirms what other sources of data have shown. As reported in Climate at a Glance: Drought, for example, the United Nations Intergovernmental Panel on Climate Change (IPCC) reports with “high confidence” that precipitation has increased over mid-latitude land areas of the Northern Hemisphere (including the United States) during the past 70 years. IPCC also has “low confidence” about any negative precipitation trends occurring globally.

Moreover, the U.S. National Oceanic and Atmospheric Administration reports America is currently is undergoing its longest period in recorded history with less than 40 percent of the country experiencing “very dry” conditions. Also, the United States in 2017 – and then again in 2019 – registered its smallest percentage of land area experiencing drought.

Figure 1: Percentage of United States experiencing “very wet” (in green) and “very dry” (in yellow) conditions. Source: National Oceanic and Atmospheric Administration: https://www.ncdc.noaa.gov/temp-and-precip/uspa/wet-dry/0.

Because drought is a primary climate component that would affect wildfires, it is not surprising to find real-world data show the number of wildfires and acres burned have fallen in recent decades, as well.

EPA’s Climate Change Indicators document discussing drought examines the ups and downs in dryness in different locations in different years across the United States. The only conclusion one can draw from the document and the data about drought in the United States is that the modest warming of the past 150 years has produced no measurable change in the incidences or severity of drought.

H. Sterling Burnett, Ph.D. is managing editor of Environment & Climate News and a research fellow for environment and energy policy at The Heartland Institute. Burnett worked at the National Center for Policy Analysis for 18 years, most recently as a senior fellow in charge of NCPA’s environmental policy program. He has held various positions in professional and public policy organizations, including serving as a member of the Environment and Natural Resources Task Force in the Texas Comptroller’s e-Texas commission.

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