New paper finds extreme droughts were more common 200-300 years ago

A paper published today in Environmental Research Letters uses tree-ring proxies to reconstruct drought conditions of the American Southeast from 1665 to 2010. The authors find "The reconstruction shows that the recent droughts are not unprecedented over the last 346 years. Indeed, droughts of extended duration occurred more frequently between 1696 and 1820. Our results indicate that the era in which local and state water supply decisions were developed and the period of instrumental data upon which it is based are amongst the wettest since at least 1665."

Environmental Research Letters Volume 7 Number 1

N Pederson et al 2012 Environ. Res. Lett. 7 014034 doi:10.1088/1748-9326/7/1/014034

A long-term perspective on a modern drought in the American Southeast

N Pederson^1,2,8, A R Bell², T A Knight³, C Leland^1,4, N Malcomb^1,5, K J Anchukaitis², K Tackett¹, J Scheff¹, A Brice¹, B Catron¹, W Blozan⁶ and J Riddle⁷

Show affiliations

Tag this article Full text PDF (515 KB) Enhanced article HTML

AbstractReferencesSupplementary Data

Letter

The depth of the 2006–9 drought in the humid, southeastern US left several metropolitan areas with only a 60–120 day water supply. To put the region's recent drought variability in a long-term perspective, a dense and diverse tree-ring network—including the first records throughout the Apalachicola–Chattahoochee–Flint river basin—is used to reconstruct drought from 1665 to 2010 CE. The network accounts for up to 58.1% of the annual variance in warm-season drought during the 20th century and captures wet eras during the middle to late 20th century. The reconstruction shows that the recent droughts are not unprecedented over the last 346 years. Indeed, droughts of extended duration occurred more frequently between 1696 and 1820. Our results indicate that the era in which local and state water supply decisions were developed and the period of instrumental data upon which it is based are amongst the wettest since at least 1665. Given continued growth and subsequent industrial, agricultural and metropolitan demand throughout the southeast, insights from paleohydroclimate records suggest that the threat of water-related conflict in the region has potential to grow more intense in the decades to come.