Embedded Files
Future
Future
PDSI is Palmer Drought Severity Index, an indirect measure of soil moisture, relative to local baseline climate. SC means self-calibrating.
"The index is the difference between the amount of precipitation required to retain a normal water-balance level and the amount of actual precipitation."
Light blue (-4.0 to -5.0) is extremely wet, red (+4.0 to +5.0) is extremely dry.
These 10-year averages did not occur in the model results before 2000,
Baseline climate period is probably a 30-year period before 1965.
The maps display soil moisture, not precipitation. With the same amount of rain and more evaporation, soil moisture decreases.
Note that southern Europe is extremely dry by the 2060s and especially the 2090s, perhaps Saharan.
The USA is a lesser case of such dryness.
So are the much of the Amazon basin and the Andes, central America, southern Africa, and Australia.
Note also the increasing soil moisture around the Acrtic.
Extremely wet conditions prevail in Indonesia, India, equatorial east Africa, Ecuador, and southern New Zealand.
Aiguo Dai, Kevin Trenberth et al.
The two maps below are from IPCC 5, Technical Assessment (2013).
Human Warming Has Begun Era of Temperature-Dominated Droughts in US West 1124.rtf - Our observational analysis shows that, since around 2000, rising surface temperature and the resulting high evaporative demand have contributed more to drought
severity (62%) and coverage (66%) over the WUS than precipitation deficit. The unprecedented 2020–2022 western US drought exemplifies this shift in drought drivers. High evaporative demand accounted for 61% of its severity, compared to 39% from precipitation deficit.
Past
Past
Articles
Recent Droughts Are ‘Slow-Moving Global Catastrophe' - UN 0725.rtfWarming Accelerates Global Drought Severity 0625.rtfMulti-Year Droughts Are Worsening. Here’s Where They Have the Most Effects. 0125.rtfClimate Crisis ‘Wreaking Havoc’ on Earth’s Water Cycle 0125.rtf3:4 of Earth’s Land Got Drier in Recent Decades - UN 1224.rtfWhy Hydropower Is Failing This Nation — and Could Fail Others 1124.rtfWhy Future Droughts Will Not Be about Rain 1124.rtfExtreme Drought Areas Tripled in Size since 1980s 1024.rtfDrought Touches 1:4 of Humanity, Disrupting Lives Globally 0124.rtfUN Drought Report Highlights ‘Silent’ Threat to Warming Planet 1223.rtfExtreme Droughts by 2030 - Dai 0111 2.pdfExtreme Droughts by 2030 - Dai 0111.pdfVery Hot and Very Dry Conditions Have Doubled Worldwide 1118.rtfNo Rain for Decades - Stand by for the ‘Megadroughts’, Scientists Warn 0914.rtfGlobal Drought Threatens Water, Food Supplies. Get Used to It. 0914.rtfShrinking Aquifers in Drought-Stricken Areas 0613.rtfGlobal Drought a New Normal 1012.rtfExtreme Droughts by 2030 1010.rtf - This is a summary of the above study.50-Year Droughts Plague World's Breadbaskets 0309.rtfClimate Change Drives Water Shortages for Half the World 1108.rtfIncreasing Drought - Past & Future - Dai 0812.pdfArticles
Also available at https://journals.ametsoc.org/view/journals/hydr/5/6/jhm-386_1.xml for "A Global Dataset of Palmer Drought Severity Index for 1870–2002: Relationship with Soil Moisture and Effects of Surface Warming" in Journal of Hydrometeorology, December 1, 2004, pp. 1117-1130.
Also available at https://journals.ametsoc.org/view/journals/hydr/5/6/jhm-386_1.xml for "A Global Dataset of Palmer Drought Severity Index for 1870–2002: Relationship with Soil Moisture and Effects of Surface Warming" in Journal of Hydrometeorology, December 1, 2004, pp. 1117-1130.
Two key figures are excerpted below, with Dr. Fry's annotations.
The slide below summarizes what has been happening with water tables, as groundwater is used ever more to cope with droughts and supply irrigation water for the Green Revolution.
Section Map: Droughts, Deserts & Fires
Page updated
Google Sites
Report abuse