Forests burn; that is normal and natural . Some trees even depend on fire for survival ! For example, some seeds will only sprout into plants in the presence of smoke . If there was no fire, then forests would become dominated by a few species, with much less variety . So fires themselves aren’t bad per se.
However, climate change is making fires more FREQUENT, STRONGER and LARGER [5,11,12]. For example, compared to the 1970s and 80s, fires in the Western USA are happening 5x as often, are covering 6x the area, and lasting almost 5x times as long [3,4]. Even though much of this forest is adapted to burning, this change in fire pattern means there is not enough time between fires for trees to recover . Even seeds that need smoke to grow can be ‘overburned’, meaning they cannot grow into trees .
Moreover, fires are happening in areas which are NOT adapted to frequent burning . In the summer of 2019, the amount of burning forest in and near the Arctic circle is higher than has been seen in at least 10,000 years . Many fires have been in areas with peat, which releases huge amounts of CO2 when it burns .
Why is there more fire? Climate change causes more severe droughts, meaning soil and plants are drier [15,8]. So, when lightning strikes or a person lights a flame, a fire starts much more easily . The current South American fires, however, are caused mostly by deliberate burning .
This is one reason why planting trees in not always the best solution. Trees we plant now will gradually take up CO2 temporarily, but they may then release it again if they burn in the future [13,14].
Can we reduce the impact of forest fires? Many fires are started by people – so careful use of hot objects, such as cigarettes, is important . Controlled burns can be used to prevent wood building up too much, meaning there is less fuel for a fire [6,8]. However, fires will likely continue to become more severe with climate change, causing loss of forests and the wildlife to which they are home , destruction of buildings, and billions of dollars in fire control and damage repair .
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