the conversation: In regions too remote for the TV cameras, satellite images reveal vast fires covering thousands of square kilometres in smoke. This is what’s happening in Siberia, right now. by Stefan H. Doerr and Cristina Santin
'First, satellite data has long shown that Russian government statistics are substantial underestimations of actual ﬁre activity. Second, the annual area burned in boreal Asia (predominantly Siberia) is particularly variable, compared to the world’s other main vegetation zones. On average around 5m hectares have burned every year between 2001 and 2012, but this covered a range of more than than 15m in 2003 to less than 3m in 2005. The area burned so far this year in Siberia is well within that range, but then we’ve only just reached midsummer – the season is not yet over.
'Just like boreal Canada, temperatures in Siberia are increasing faster than in many other parts of the world and this trend is expected to continue. Rising temperatures lead to drier vegetation, to fuel the fires, and more lightning, which increases the risk of fire. A hotter climate also lengthens the season during which fires occur. These factors combined are expected to increase fire activity in this region.
'What is particularly worrying here is some of the fires in Siberia and other boreal regions affect peatlands which are gradually thawing thanks to global warming. This has a knock-on effect on the climate. When they burn deep into the ground peatland fires can release carbon that has accumulated over millennia and turn these peatlands from being net carbon sinks to long-term carbon emitters. So irrespective of discrepancies in reporting of fires in Siberia and the fact that fires are a natural feature of boreal forests, we can expect more fires and more associated greenhouse gas emissions in boreal regions in a warming world.'