climate change impacts agriculture in many ways with changes in temperature precipitation and climatic variability affecting the timing and length of growing seasons and yields and thereby exacerbating land degradation and contributing to water scarcity agrawala and fankhauser eds as a proxy the remotely sensed ndvi which has been shown to be related to biophysical variables that control vegetation productivity and land atmosphere fluxes is also used to estimate vegetation change bai and others for instance it is estimated that in southern africa yields could fall by up to per cent between and intergovernmental panel on climate change b and that by million additional people could be at risk of hunger as a direct consequence of climate change united nations development programme overview p they also impact landsurface albedo so as to engender adverse weather patterns university of east anglia overseas development group