Meanwhile... Siberia is experiencing unusual heat

Meanwhile in Siberia, temperatures rose to a record high of 30°C last May. And this unusual heat feeds another fear as the Arctic fire season begins…

Transcript

00:00Russia has just experienced its warmest winter on record. The trend has continued through

00:19March, April and May with some places in Siberia experiencing temperatures 10 to 20 degrees

00:25Celsius above average. Without significant rainfall this can increase the likelihood

00:39of fires due to the high temperatures drying out both the vegetation at the surface but

00:45also the soil. The carbon emitted from these wildfires is re-sequestered when the vegetation

01:11grows back as part of a natural carbon neutral cycle. However, an increasing frequency and

01:18severity of fires in the Arctic might lead to permanent changes in these ecosystems where

01:24we could see the replacement of forests with shrubs or grasses. The carbon lost in the

01:29fires may not be re-sequestered in the near future. It's very difficult to predict what

01:34will happen this summer, although the unusual warm temperatures in Siberia so far this year

01:39will have led to an abundance of dry vegetation and that will certainly be ready to burn

01:44if there were to be a source of ignitions. They've been well documented in places like

02:01Alaska. In the summer a large and intense fire might ignite underground fuels. This

02:08could be in the form of the roots of dead trees or it could be the soil itself. The

02:12fire can slowly smoulder through the winter underneath the snow and in the spring when

02:18the snow is melted and the surface vegetation is dry, the smouldering underground fire might

02:23re-emerge and spread through the surface vegetation. The snow is now melting in the Arctic and

02:31so now is the time to be looking out for these potential zombie fires. The fires in

02:47the Amazon are used to clear land for agriculture. It's the same story with these Arctic fires

02:53as well and in Arctic regions. While some fires are started by lightning strikes, many

02:58are also ignited by people for clearing the land. If these fires have ignited the peat

03:16soils, the carbon lost from these fires has taken thousands of years to accumulate in

03:22the soil and this is something that cannot be reversed within the timescales of concern

03:26for climate change. Like in many other countries, restrictions need to be placed on when people

03:31should be allowed to burn their land. This can reduce the number of ignitions and the

03:36potential for accidental wildfires spreading out of control. For fires that are started

03:41naturally by lightning, there's very little we can do about these fires apart from taking

03:46measures to halt human-caused climate change that is responsible for global warming and

03:51this of course is a much longer term effort and what we do now will influence the fire

03:57activity that we will experience in 30 or 40 years time.