Climate-linked increasing vegetation fires in global high mountains

The spatiotemporal variability of vegetation fires is essential for understanding changes in the climate and ecosystem in mountainous regions. MODIS Collection 6 active fire products indicate that the area burned by vegetation fires declined globally from over 4.27 million km(2) to less than 3.52 million km(2) annually during 2001-2021. In contrast, global high mountains higher than 3000 m have experienced an overall increase in their burned area and suffered record-breaking wildfires from August to December 2020. Although high mountains accounted for less than 0.03% of the global burned area during 2001-2021, this proportion had more than tripled by 2020. This unprecedented wildfire record in 2020 could be mainly caused by favorable fire weather conditions such as low relative humidity, low soil water and high temperature.