Glacier retreat dominates surface warming by land cover change in Switzerland

Between 1985 and 2018, 12% of Switzerland’s area changed its land cover, with significant impacts on land surface temperatures. Similar to other industrialized countries, settlements have grown, mostly at the expense of farmland, resulting in additional heating due to vegetation loss and surface sealing. Landsat-derived LST trends at 100 m spatial resolution show that the strongest warming from land cover change is associated with glacial retreat. Over the last four decades, ice loss has led to an average warming rate of 0.05 K/yr relative to surfaces with stable ice cover. Although land cover changes associated with the concurrent expansion of vegetation result in relative surface cooling, this is insufficient to counter the warming caused by ice retreat. The combination of relative surface cooling and warming due to land cover changes that occur in response to climate warming may contribute to the observed phenomenon of elevation-dependent warming. Furthermore, surface warming near the retreating ice is likely to affect the microclimate, possibly accelerating glacier retreat and promoting heat propagation to greater depths, which may lead to permafrost thawing and destabilization of steep rocky slopes.