Modelling future parasite range expansion with warming climate
We used a series of climate-based models to predict the change in parasite range with temperature. First, we extracted monthly values for minimum temperature and maximum temperature for the year 2021-2040 for four Himalayan sites. We used Madhmaheshwar as a nearby site (30°38′13″N 79°12′58″E) as an alternative to Shokharakh due to non-availability of data.
We used data from eight global climate models available on WorldClim (www.worldclim.org) . These global climate models (GCM) are BCC-CSM2-MR, CNRM-CM6-1, CNRM-ESM2-1, CanESM5, IPSL-CM6A-LR, MIROC-ES2L, MIROC6, MRI-ESM2-0. We extracted temperature data for the year 2021-2040 at a spatial resolution of 2.5 minutes to estimate the effect of future climate change on malaria transmission. A set of scenarios have been chosen to provide a range of distinct end of century climate change outcomes by the energy modelling community, which mainly deals with greenhouse gas emission scenarios driven by different socioeconomic assumptions. We considered the shared socioeconomic pathway SSP2-4.5, which provides one scenario for global emissions, consistent with certain assumptions about how socio-economic trends might evolve in the future. We selected SSP2-4.5 because it represents a “middle of the road” scenario i.e., the world follows a path in which social, economic, and technological trends do not shift markedly from historical patterns.
To extract the minimum temperature and maximum temperature for the year 2021-2040 values, we use the GIS software QGIS (https://www.qgis.org). We compute the average of predicted monthly mean temperature across all eight GCM models.