According to a new study by National Center for Atmospheric Research (NCAR) scientist, Aiguo Dai, the United States along with many other heavily populated countries in the Western Hemisphere is looking at a growing threat of severe and extended drought in the years to come. The study reports that warming temperatures attributed to climate change will most likely cause increasingly dry conditions across much of the globe in the next 30 years. This drought may reach proportions in some areas by the end of this century that have rarely, if ever, been seen in modern times.
Dai used a compilation of 22 different computer climate models, a comprehensive index of drought conditions, and analyses of previously published studies ton conclude that much of the Western Hemisphere as well as large parts of Eurasia, Africa, and Australian are likely to experience extreme drought by 2030.
At the same, time higher-latitude areas from Alaska to Scandinavia will probably grow moister. Dai cautioned that the findings are based on the most up-to-date projections of greenhouse gas emissions. The future will depend on several factors, including actual emissions of greenhouse gases along with natural climate cycles such as El Niño.
The new findings are part of a longer review article in Wiley Interdisciplinary Reviews: Climate Change. NCAR’s sponsor, the National Science Foundation (NSF) supported the study.
In a press release from NSF dated October 19, Eric DeWeaver, program director in the organization’s Division of Atmospheric and Geospace Sciences which funds NCAR, said “This research does an excellent job of placing future warming-induced drought in the context of the historical drought record. The work argues credibly that the worst consequences of global warming may come in the form of reductions in water resources.”
In the same release Dai was quoted, saying, “We are facing the possibility of widespread drought in the coming decades, but this has yet to be fully recognized by both the public and the climate-change research community. If the projections in this study come even close to being realized, the consequences for society worldwide will be enormous.”
Countries that may face significant drought include:
- Most of Latin America including sections of Mexico and Brazil
- Regions that border the Mediterranean Sea
- Much of Southwest Asia
- Most of Africa and Australia, with especially dry conditions in parts of Africa
- Southeast Asia, particularly regions within China and neighboring countries
The areas where drought risk is expected to decrease during this century are much of Northern Europe, Russia, Canada, and Alaska.
A 2007 assessment by the Intergovernmental Panel on Climate Change (IPCC) showed that subtropical areas would probably have a decline in precipitation, with high-latitude areas getting more in the way of rainfall.
Dai’s previous studies have predicted that climate change may already be having a drying effect on parts of the world. In the new study, Dai posed a basic question: how will climate change affect future droughts?
Dai’s research, along with a common drought measure called the Palmer Drought Severity Index, shows that by the 2030s, regions in the U.S. and overseas could experience particularly severe conditions. There are, Dai admits, inconsistencies, both in global climate models and in how well the Palmer index actually captures the range of conditions that the future climate may produce.
Article by Julie Mitchell, appearing courtesy Celsias.
