TY - JOUR
T1 - Anthropogenic influence on the drivers of the Western Cape drought 2015-2017
AU - Otto, Friederike E.L.
AU - Wolski, Piotr
AU - Lehner, Flavio
AU - Tebaldi, Claudia
AU - Van Oldenborgh, Geert Jan
AU - Hogesteeger, Sanne
AU - Singh, Roop
AU - Holden, Petra
AU - Fučkar, Neven S.
AU - Odoulami, Romaric C.
AU - New, Mark
PY - 2018/11/29
Y1 - 2018/11/29
N2 - In the period 2015-2017, the Western Cape region has suffered from three consecutive years of below average rainfall - leading to a prolonged drought and acute water shortages, most prominently in the city of Cape Town. After testing that the precipitation deficit is the primary driver behind the reduced surface water availability, we undertake a multi-method attribution analysis for the meteorological drought, defined in terms of a deficit in the 3 years running mean precipitation averaged over the Western Cape area. The exact estimate of the return time of the event is sensitive to the number of stations whose data is incorporated in the analysis but the rarity of the event is unquestionable, with a return time of more than a hundred years. Synthesising the results from five different large model ensembles as well as observed data gives a significant increase by a factor of three (95% confidence interval 1.5-6) of such a drought to occur because of anthropogenic climate change. All the model results further suggest that this trend will continue with future global warming. These results are in line with physical understanding of the effect of climate change at these latitudes and highlights that measures to improve Cape Town's resilience to future droughts are an adaptation priority.
AB - In the period 2015-2017, the Western Cape region has suffered from three consecutive years of below average rainfall - leading to a prolonged drought and acute water shortages, most prominently in the city of Cape Town. After testing that the precipitation deficit is the primary driver behind the reduced surface water availability, we undertake a multi-method attribution analysis for the meteorological drought, defined in terms of a deficit in the 3 years running mean precipitation averaged over the Western Cape area. The exact estimate of the return time of the event is sensitive to the number of stations whose data is incorporated in the analysis but the rarity of the event is unquestionable, with a return time of more than a hundred years. Synthesising the results from five different large model ensembles as well as observed data gives a significant increase by a factor of three (95% confidence interval 1.5-6) of such a drought to occur because of anthropogenic climate change. All the model results further suggest that this trend will continue with future global warming. These results are in line with physical understanding of the effect of climate change at these latitudes and highlights that measures to improve Cape Town's resilience to future droughts are an adaptation priority.
KW - climate change
KW - drought
KW - extreme event attribution
UR - http://www.scopus.com/inward/record.url?scp=85060143864&partnerID=8YFLogxK
U2 - 10.1088/1748-9326/aae9f9
DO - 10.1088/1748-9326/aae9f9
M3 - Article
AN - SCOPUS:85060143864
VL - 13
JO - Environmental Research Letters
JF - Environmental Research Letters
SN - 1748-9326
IS - 12
M1 - 124010
ER -