By Srirangam Sriram, Sriram's IAS, New Delhi.
A zombie fire is a fire that continues to burn underground and then reignites on the surface after a period of time. Embers deep in organic soils such as peatlands can spark into flames weeks, months and even years later. Scientists monitoring Alaska have seen a similar phenomenon. Since 2005, scientists on the ground in Alaska have identified 39 such "holdover fires", as they are also called.
What has caused the Zombie fires?
- There has been tremendous warmth in the Arctic that has led to a lot of drying, making the peat soils ripe to burn.
- Last year's massive blazes were fuelled by record heat. Parts of Siberia and Alaska were up to 10 degrees Celsius warmer than normal for weeks at a time.
- In June 2019 - the hottest on record, going back 150 years - the blazes are estimated to have released 50 million tonnes of CO2 into the atmosphere, equivalent to Sweden's annual emissions.
- Fire managers have noted increasing occurrences where fires survive the cold and wet boreal winter months by smoldering and re-emerged in the subsequent spring.
- The cumulative effect of last year's fire season in the Arctic may feed into the upcoming season and could lead to large-scale and long-term fires across the same region once again.
- The risk of wildfires increases with hot weather and low humidity, and Europe, in particular, has seen record temperatures for March and April this year.