The latest research shows rapid and dramatic increase in tree loss from fires around the world, much of which can be attributed to climate change. Such loss through forest fires will only contribute to the growth in atmospheric emissions the world is attempting to manage.
The data shows a global trend in forest loss due to fire from 2001 to 2019, driven by near-uniform increases across the tropics, subtropical, and temperate Australia, and boreal Eurasia.
The doubling of tree loss in two decades suggests a problem that cannot be managed by fire protection services, only by critically curbing climate change.
The rapid increase in forest fire loss potentially undermines the role of permanence for tree-related carbon offsets – critical to their use in offsetting emissions.
Data composed into detailed maps of forest fire loss over a 20-year period to 2020 shows the accelerating effects of climate change in sparking and sustaining fires across the globe, especially in the northern regions of Russia, Canada and the US. Trees are burning at roughly twice the rate they were twenty years ago and climate change is accelerating that trend.
Climate change and human-induced destruction
Deforestation in the Amazon in the first half of 2022 was 80% greater than in the first half of 2018, with new research finding that this equates to roughly 1,500 square miles, an area five times the size of New York City. Yet while focus remains on the drivers of man-made deforestation, there has been less focus on the extent of global tree loss from fire.
The results of a recent University of Maryland study Global Trends of Forest Loss Due to Fire From 2001 to 2019 show the first 30 metre resolution satellite based map of tree loss due to fire. The new ‘tree cover loss from fires’ data builds on the existing annual tree cover loss data from UMD by providing additional context on where fires are driving loss.
The World Resources Institute (WRI) used the data to calculate that forest fires now result in 3 million more hectares of tree cover loss per year compared to 2001 — an area roughly the size of Belgium. That represents a quarter of all tree loss over the period – but even more worrying was the fact that a third of all that loss took place in 2021.
It suggests that with the phenomenon driven principally by climate change and human-induced destruction, the only way to arrest the problem is by halting climate change and stopping deforestation.
Global Forest Watch has explained the carbon feedback loop of forest fires. Extreme heat waves are estimated to be 5x more likely than they were 150 years ago and they are expected to continue to increase in frequency. As the temperature warms, the trees dry out and present an environment ripe for larger, more frequent fires. This in turn leads to higher emissions which contributes to climate change, higher temperatures and more forest fires.
Mapping of global forest fire loss data has been put together over an almost 20 year period of 2001-2019
For the first time researchers have been able to map to a 30 –m resolution forest loss, enabling it to be established whether the trees were standing before or previously slashed such as in slash and burn practice. Fires erupting with standing trees are likely down to climate change or intentional illegal burning.
Analysis of Landsat satellite images with higher resolution techniques has produced a clearer insight into the types of forest fire globally enabling a picture to emerge of the extent and cause of destruction and the threat to remaining forests.
In tropics deforestation makes forests vulnerable to unchecked fire spread
The study points out how in boreal forests, fires are a part of the ecosystem dynamics, while in the humid tropics, fires are largely human-induced and lead to forest degradation.
An increasing trend of forest loss due to fire is observed in primary tropical forests of Latin America and Africa.
With more severe and extreme weather events this trend can only increase, leading to more climate feedbacks and long-term ecosystem damage. Clearing land for agriculture is the principal reason forests are burnt in the tropics but it tears the integrity of the ecosystem, allowing drying to take hold and fires to spread from purposefully selected ones.
Boreal forests in Eurasia pose grave threat to increasing climate change
But the greatest area of land to have been lost to forest fire, about half the total global increase, were boreal forests, especially in Russia, and in Canada and the US. Global Forest Watch analysed the data and reported that these three countries combined lost 7.8 million hectares or 84% of all fire-related loss in 2021.
This is attributed to the fact that northern high-latitude regions are warming at a faster rate than the rest of the planet, laying the ground for longer and more severe fire seasons.
The carbon emissions released on top of the removal of the primary source of carbon sinks are cause for serious concern especially as the result – the lack of forest and soil to produce moisture and absorb carbon – exacerbates the problem and creates a negative feedback loop.
The soils in boreal forests store especially high concentrations of carbon, known as deep soil carbon, as carbon is stored deep within the soil and locked into permafrost. Fast warming in the region is thawing out the permafrost which will drive further increases in atmospheric emissions.
In 2021 in Russia, 5.4 million hectares of forest was burnt, the most recorded in the last 20 years and a 31% increase over 2020. Prolonged heatwaves, like with many other fires, was responsible.
Study highlights precariousness of forest carbon offsets
Most carbon offsets are tree based/ forest projects. Not only is the integrity of these projects extremely hard to ensure as they may shift deforestation elsewhere, forests across the world are becoming highly vulnerable to fire risk.