Deforestation-induced surface warming is influenced by the fragmentation and spatial extent of forest loss in Maritime Southeast Asia

Deforestation in the tropics causes warming which contributes to regional climate change. Forest loss occurs over a broad range of spatial scales, producing a variety of spatial patterns of cleared and forested land. Whether the spatial attributes of these patterns influence the resulting temperature change remains largely unknown. We adopted a differences-in-differences approach to analyse remotely-sensed forest loss and land surface temperature (LST) data in maritime Southeast Asia. We found that deforestation increased LST, as expected, but that the temperature increases were smaller when forest loss produced more fragmented landscapes in which non-forest and forest edges were heavily interlaced. Temperature increases were greater where the forest loss was more extensive. Warming also extended beyond the location of forest removal, so that forest loss increased temperatures in undisturbed locations up to 6 km away. Different spatial patterns of land clearing, for example, as might be produced by small-holder agriculture as opposed to large-scale deforestation, would therefore have different impacts on the local climate. Conserving forests within 4 km of farmland, urban areas or other sensitive environments may help to avoid temperature increases that reduce land productivity and worsen human health.