Aedes and Climate Change


Aedes and Climate Change

In a study by Ryan et al. 2019, researchers modeled the number of months populations would be at risk of exposure to Aedes aegypti and Aedes albopictus transmitted viruses given different climate change scenarios. Here is the author summary from paper “The established scientific consensus indicates that climate change will severely exacerbate the risk and burden of Aedes-transmitted viruses, including dengue, chikungunya, Zika, and other significant threats to global health security. Here, we show more subtle impacts of climate change on transmission, caused primarily by differences between the more heat-tolerant Aedes aegypti and the more heat-limited Ae. albopictus. Within the next century, nearly a billion people could face their first exposure to viral transmission from either mosquito in the worst-case scenario, mainly in Europe and high-elevation tropical and subtropical regions. However, while year-round transmission potential from Ae. aegypti is likely to expand (particularly in south Asia and sub-Saharan Africa), Ae. albopictus transmission potential is likely to decline substantially in the tropics, marking a global shift towards seasonal risk as the tropics eventually become too hot for transmission by Ae. albopictus. Complete mitigation of climate change to a pre-industrial baseline may protect almost a billion people from arbovirus range expansions; however, middle-of-the-road mitigation could produce the greatest expansion in the potential for viral transmission by Ae. albopictus. In any scenario, mitigating climate change would shift the projected burden of both dengue and chikungunya (and potentially other Aedes transmitted viruses) from higher-income regions back onto the tropics, where transmission might otherwise begin to decline due to rising temperatures.”

The two Aedes mosquito species under current climate prediction scenarios are shown here in interactive maps. The darkness of the color red is associated with more months of suitability for the mosquito species with 12 months being the highest and 1 month being the lowest. To interact with the maps please use the zoom tools or enter full screen mode for full functionality.

Raster datasets of Aedes spp. suitability were retrieved from Harvard Dataverse (Ryan 2019 Ae. aegypti and Ae. albopictus). The datasets were converted to polygons and exported as shapefiles in ArcMap (ver. 10.6.1). Shapefiles for months of suitability were added as layers and used to create interactive maps in Mapbox studio.

Aedes aegypti

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Display a map

Photo Credit: Phillip Boersch-Supan

Aedes albopictus

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Aedes albopictus suitability

Photo Credit: Phillip Boersch-Supan

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