The latest research shows a shocking 60 per cent rise in carbon dioxide emissions from wildfires since 2001, with emissions nearly trebling in the climate-vulnerable boreal forests of the northern hemisphere, spanning great expanses of Alaska, Canada, and Russia. Without addressing key contributors to climate change, including fossil fuel emissions, further escalation of forest fires cannot be avoided, the report asserts.
The global investigation was spearheaded by scientists at the University of East Anglia (UEA) and unveiled in the journal Science. The researchers categorised different global areas into “pyromes” – zones where similar environmental, human and climatic factors influence wildfire cycles.
One of the most significant pyromes covers Eurasian and North American boreal forests where fire emissions swelled almost threefold from 2001 to 2023. Predominantly located in cooler zones with permafrost, these forests comprise one of Earth’s largest undisturbed ecosystems. Huge amounts of carbon are stored in these forests’ trees, undergrowth, and soils.
In extratropical forests more generally, CO2 increases equated to an added half a billion tonnes of carbon annually, as the focus of emissions veered away from tropical forests.
These heightened emissions are associated with an increase in weather conditions conducive to wildfires, including hot, dry spells during heatwaves and droughts, as well as more rapid rates of forest growth generating additional plant fuels. Both of these trends are boosted by swift temperature rises in the northernmost latitudes, which are happening at double the global average pace, the report finds.
The research shows not just the growing area impacted by wildfires over the past two decades, but also the worsening intensity. The global rate of carbon combustion, marking the severity of fires based on how much carbon is emitted for each area burned, surged by almost 50 per cent in forests worldwide.
Dr Matthew Jones from the Tyndall Centre for Climate Change Research at UEA expressed concerns about the escalating percentages and severity of global forest fires, leading to a striking surge in carbon emissions worldwide. Furthermore, he pointed out noteworthy shifts in worldwide forest fire geography that can be attributed primarily to the escalating influence of climate change on boreal forests globally.
He underscores the urgency to keep global warming at bay and achieve rapid strides towards net zero emissions to protect vital forest ecosystems from the escalating threat of wildfires. Forests are pivotal globally for their carbon storage abilities, and their growth aids in extracting CO2 from the atmosphere, thereby curbing global warming rates. They also serve a vital function in achieving international climate targets through the implementation of afforestation and reforestation projects aimed at carbon extraction from the atmosphere and counterbalancing human emissions from difficult to control sectors like aviation and certain industries.
The success of such schemes hangs on the permanent storage of carbon in forests, which wildfires jeopardize. According to the study, an increase in widespread and severe forest fires indicates a disbalance between emissions and the carbon captured during post-fire recovery.
Dr Jones expressed a growing worry about the rising slope towards higher extratropical forest fire emissions. This trend signals a growing susceptibility of forests posing a major hurdle towards global targets to combat climate change. He emphasized the importance of closely monitoring how the observed rise in fire severity impacts carbon storage in forests in the coming years considering that forests recuperate poorly after severe fires.
Interestingly, an increase in carbon emissions from forest fires starkly contrasts with the reduced burning of tropical savannahs globally. Past studies have shown a one-fourth reduction in areas affected by all types of fires (both forest and non-forest) since 2001 due to this reason. The severity of forest fires leads to them releasing greater amounts of harmful smoke, posing a threat not only to communities near these fires but also to distant populations exposed to the poor air quality resulting from the smoke.