A number of extra new research present that drought is rarer and extra extreme now than it was 1000’s of years in the past – cotton wool?
Reposted by TheNoTricksZone
By Kenneth Richard on June 14, 2021
Scientists continue to publish new drought reconstructions indicating that there have been far more frequent and severe droughts in the past several thousand years than anything seen in modern times.
A new study (Berg and McColl, 2021) points out that there have long been “qualitatively incorrect” estimates of the impact of modern and future warming on drought trends and the extent of arid areas, as atmospheric drought is “not an accurate indicator of future arid extent”. Consequently, the authors propose that “no global dry area expansion under greenhouse warming, contrary to previous claims based on atmospheric drought. “
In fact, droughts along the west coast of the United States are not being driven by rising greenhouse gas concentrations and warming, but “predominantly” [84%] driven by internal atmospheric variability “and cooling sea surface temperatures (Baek et al., 2021).
Image source: Baek et al., 2021
Many new drought reconstructions even show that modern times have not seen any increasing drought trends compared to the last few thousand years.
1. Zhu et al., 2021
“The periods 1931-1938 and 1909-1917 were the longest and heaviest rainy and dry periods.”
Image source: Zhu et al., 2021
2. Brice et al., 2021
“Despite its significant impact recently, the drought of the 2000s is only classified as the sixth driest course in the reconstruction of the CHU, is only half or less as long as the drought of the 18th year with snowpack below average) 50-75% less more serious than these others. “
“The extent of the 1950s drought in rebuilding the ESC is only 67% of the extent of the top-tier droughts in the same record, 1818-1834 and 1728-1744.”
“The 20th century has less frequent and long dry or wet periods. … Our results also agree with studies that document pre-instrumental droughts that were more intense or longer than the drought of the 20th century (Woodhouse and Overpeck, 1998, Novak, 2007). “
Image source: Brice et al., 2021
3rd Esper et al., 2021
“For the final reconstruction, the instrumental target data will be adjusted to enable realistic estimates of midsummer precipitation up to 729 CE. The reconstruction contains significantly more low-frequency variability than other high-resolution hydroclimate records from the eastern Mediterranean, including extended dry periods from 1,350 to 1,379 CE (39 ± 4.5 mm) and 913 to 942 (40 ± 8.4 mm) and wet periods from 862 to 891 (86 ± 11 mm) and 1,522 to 1,551 (80 ± 3.5 mm), based on the long-term mean of 61 mm. The most recent 30-year period from 1986 to 2015 is characterized by above-average June-July precipitation (73 ± 2 mm). “
Image source: Esper et al., 2021
4th Yadava et al., 2021
“1774 (SPEI -3.11) and 1787 (SPEI +2.13) are the driest and wettest years, respectively.”
“The five-year mean value of the reconstructed SPEI showed droughts in the years 1818–1822, 1798–1802, 1813–1817, 1793–1797, 1958–1962.”
Image source: Yadava et al., 2021
5. Kalisa et al., 2020
“The results showed that years of severe drought ranged from 1920-22, 1926-29, 1942-46 and 1947-51 with values of 2.2, 3.2, 3.4 and 2.6, respectively, while years with low drought severity from 1930-31 ranged, 1988-89 and 2001-02 with values of 0.2, 0.12 and 0.15, respectively. “
“The longest droughts occurred from 1926-29, 1937-41, 1942-46, 1947-51, 1952-56 and 1958-61 with values in years as 3, 4, 4, 4, 4 and 3 years, respectively the shortest droughts occurred in 1 year and ranged from 1930-31, 1964-65, 1979-80, 1981-82, 1983-84, 1988-89, 1991-92, 1993-94, 1996-97 and 2001- 02. “
Image source: Kalisa et al., 2020
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