A significant new study indicates that carbon dioxide emissions from wildfires have increased by 60% worldwide since 2001, with some of the most climate-sensitive northern boreal forests seeing nearly a threefold increase.
A significant new study indicates that carbon dioxide (CO2) emissions from wildfires have increased by 60% worldwide since 2001, with some of the most climate-sensitive northern boreal forests seeing nearly a threefold increase.
Conducted by the University of East Anglia (UEA) and published today in Science, the research categorized various regions of the world into ‘pyromes’—areas where patterns of forest fires are influenced by similar environmental, human, and climatic factors—highlighting the primary drivers behind the recent rise in forest fire occurrences.
This study is among the first to examine the contrasts between forest fires and non-forest fires on a global scale, revealing that in one of the largest pyromes, which includes boreal forests in Eurasia and North America, emissions from fires nearly tripled between 2001 and 2023.
Widespread increases were also observed across extratropical forests, contributing an additional half a billion tonnes of CO2 emissions each year, with the center of emissions shifting from tropical forests to extratropical areas.
The rise in emissions is associated with an increase in weather conditions that favor fires, such as hot and dry weather during heatwaves and droughts, along with greater forest growth generating more fuel for vegetation. These trends are accelerated by rapid warming in northern high latitudes, occurring at twice the global average rate.
The study highlights a troubling uptick not only in the area affected by wildfires over the past two decades but also in their intensity. The rate of carbon combustion related to fire severity, which measures how much carbon is emitted per unit of area burned, has surged by nearly 50% in forests worldwide from 2001 to 2023.
This research involved an international collective of scientists from the UK, the Netherlands, the US, Brazil, and Spain, who caution that to prevent further spread of forest fires, it’s crucial to address the main contributors to climate change, such as emissions from fossil fuels.
Dr. Matthew Jones, the lead author from the Tyndall Centre for Climate Change Research at UEA, remarked, “The rise in both the reach and intensity of forest fires has caused a substantial increase in global carbon emissions from these fires. Considerable changes in the patterns of global fires are taking place, influenced mainly by the growing impacts of climate change in boreal forests.”
“To safeguard essential forest ecosystems from the escalating danger of wildfires, we need to mitigate global warming, which emphasizes the urgency of making considerable strides towards achieving net zero emissions.”
Risks to Carbon Storage
Forests play a critical role in global carbon storage, as their growth aids in absorbing CO2 from the atmosphere, thereby mitigating global warming. They are vital for achieving international climate commitments, with reforestation and afforestation projects being implemented to absorb carbon and offset emissions from hard-to-reduce sectors like aviation and specific industries.
The effectiveness of these initiatives depends on the long-term storage of carbon in forests, and wildfires pose a significant threat to this. Extratropical fires are now emitting half a billion tonnes more CO2 than they did two decades ago, and the lasting impact will depend on how forests recover. Increasingly widespread and severe wildfires indicate that emissions are outpacing the carbon captured during post-fire recovery.
Dr. Jones, an independent research fellow with NERC, stated, “The rapid rise in emissions from extratropical forest fires signals the increasing vulnerability of forests and poses a considerable challenge to global climate change targets.”
“We know that forests struggle to recover after severe fires, thus there is significant interest in understanding how the observed increases in fire severity will affect carbon storage in forests over the coming years. This calls for our close attention.”
Rising Wildfire Effects Hidden Until Now
Notably, the increase in emissions from wildfires contrasts with the decreased burning in the world’s tropical savannas during the same timeframe. Previous research has shown that, since 2001, the total area burned by all fires (both forest and non-forest) globally decreased by 25%, mainly due to this decline.
The recent findings are significant because wildfires tend to burn more fiercely and release larger amounts of harmful smoke into the atmosphere than savanna grassland fires, posing serious risks to nearby populations and even those far away who suffer from poor air quality due to smoke exposure.
The authors argue that this study dispels the idea that a decreasing total annual area burned globally equates to reduced wildfire impacts.
“So far, the reduction in burning within typically fire-prone savannas and grasslands has hidden the substantial increases in forest fire area and severity, which have serious implications for society and the environment,” said Dr. Jones. “Our research shows that fires are increasingly occurring in areas where we least want them—forests, where they pose the greatest threat to people and essential carbon stores.”
Wildfire Management
Utilizing machine learning has been crucial to gaining new insights into the shifting global landscape of wildfires. It was applied to categorize the world’s forest ecoregions into 12 different pyromes, enabling researchers to differentiate the effects of climate change from other factors like land use.
This knowledge also provides valuable insights on which strategies may be most effective in mitigating wildfires and safeguarding forests. Dr. Jones emphasized, “Significant funding is necessary to support strategic forest management programs, engage stakeholders, and inform the public, reflecting a meaningful transition from largely reactive fire management to a more proactive approach.”
“For instance, we need to determine priority areas for management and fire breaks based on active monitoring of forest productivity, especially in the extratropics. Managing fuel loads in areas where they could pose the greatest danger during fire-prone weather is essential for reducing the severity and impact of fires when they do occur.” The study received support from various funders, including the UK Natural Environment Research Council (NERC), the European Commission Horizon 2020 program, and the European Space Agency.
The study was supported by various funders, including the UK Natural Environment Research Council (NERC), the European Commission Horizon 2020 program, and the European Space Agency.
