GH010-11
Impact of an accelerated melting on Malaria distribution over Africa.

Monday, 14 December 2020: 10:30
Virtual
Alizée Chemison1, Adrian Mark Tompkins2, Dimitri Defrance3, Margaux Charra4, Guigone Camus1, Gilles Ramstein5 and Cyril Caminade6, (1)LSCE Laboratoire des Sciences du Climat et de l'Environnement, Gif-Sur-Yvette Cedex, France, (2)Abdus Salam International Center for Theoretical Physics, Trieste, Italy, (3)The Climate Data factory, Paris, France, (4)Laboratoire des Sciences du Climat et de l'Environnement, St Aubin, France, (5)Laboratoire des Sciences du Climat et de l'Environnement, Gif-Sur-Yvette Cedex, Paris, France, (6)University of Liverpool, Liverpool, United Kingdom
Abstract:
The investigation of climate tipping points and their potential impacts on populations is a critical issue. We know from the last deglaciation that melting of the ice sheets is strongly nonlinear. Iceberg debacle in Greenland, similar to past Heinrich's events, has large impacts on the oceanic circulation. Such rapid melting slows down the Atlantic Meridional Oceanic Circulation, causing a large-scale disruption of the atmospheric circulation and thus changing the global climate. These fast melting processes and their feedbacks on the climate system are not considered in current state of the art global climate model scenarios. In addition, their impact on health have not been investigated in great details to date. Induced changes in rainfall and temperature could have important consequences on health outcomes, particularly for vector-borne diseases.

We investigate the consequences of such an accelerated melting of the Greenland ice sheet on the distribution of malaria in Africa. A freshwater flux corresponding to a partial melting of Greenland (corresponding to different additional sea level rises e.g. +0.5, +1, +1.5, +3m) is superimposed to the standard IPCC RCP8.5 scenario. We then analyze the impact of such melting on malaria risk using an ensemble of mathematical malaria models.

Based on the standard RCP8.5 scenario, malaria transmission risk increases over altitude regions in East Africa while it slightly decreases over the warmest plains of West Africa at the end of the 21st century. This signal is related to an increase in temperature which favors malaria transmission over the cold East African plateau while it causes larger mortality in mosquitoes over warmer West Africa.

The additional effect of a rapid melting of Greenland reduces the simulated increase in malaria risk over East Africa seen in standard RCP8.5 simulations (additional cooling effect), while the simulated decrease in risk over West Africa is strongly amplified because of a severe drying signal. The African monsoon significantly shifts southward leading to a significant rainfall and malaria risk increase over Southern Africa.

Our findings demonstrate the large potential impact of a rapid sea-ice melting on potential malaria burden in Africa.

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