Key Takeaways:
- The United States is benefiting from fewer and less extreme drought events as the climate modestly warms.
- The United States set records in 2017 and 2019 for having its smallest percentage of land area experiencing drought conditions.1
- The United States is undergoing its longest period in recorded history with fewer than 40 percent of the country experiencing “very dry” conditions.
- The U.N. 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, while IPCC has “low confidence” about any negative trends globally.2
Short Summary: Real-world data show drought in the United States has become less frequent and severe as the climate has modestly warmed.
Moreover, the United Nations reports “low confidence” there are negative trends globally. Droughts have always occurred, and they always will. The available evidence shows the droughts that have occurred in recent years were not caused or worsened by global warming. Instead, global and U.S. drought data show recent droughts were less frequent and severe than the droughts of the early and mid-twentieth century.
The U.S. National Oceanic and Atmospheric Administration data displayed in Figure 1 show that the United States is undergoing its longest period in recorded history without at least 40 percent of the country experiencing “very dry” conditions.3 Further, it’s important to note that the peaks in drought displayed in Figure 1, occurring around 1900, 1930, 1954, and 1978, are much higher than those experienced in the United States in the twentieth and twenty-first centuries.
Figure 1. Percentage of the United States Experiencing ‘Very Wet’ or ‘Very Dry’ Conditions
References:
- Jonathan Erdman, “Drought Coverage in the Continental U.S. Drops to a 21st Century
Record Low,” weather.com, April 12, 2019, https://weather.com/news/climate/
news/2019-04-12-drought-record-low-coverage-continental-us-april-2019 - U.N. Intergovernmental Panel on Climate Change, “Impacts of 1.5°C of Global
Warming on Natural and Human Systems,” Chapter 3, Special Report on Global
Warming, 2019, p. 191, https://www.ipcc.ch/site/assets/uploads/sites/2/2019/06/
SR15_Chapter3_Low_Res.pdf - National Centers for Environmental Information, “U.S. Percentage Areas (Very Warm/
Cold, Very Wet/Dry),” U.S. National Oceanic and Atmospheric Administration, accessed
September 27, 2023, https://www.ncdc.noaa.gov/temp-and-precip/uspa/wet-dry/0
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Illustration of drought conditions. Image licensed from pexels.com.