Deforestation fires are major contributors to global emissions, but blazes in carbon-rich terrain may be adding far more greenhouse gases than previously thought.
In 2019 and 2020, blazes in Brazilian and Indonesian forests were responsible for between 3 and 7% of the planet’s greenhouse gas emissions (GHG). Now a new study published in Frontiers in Climate shows well up to 60% of that impact is likely to have been caused by peatland fires, a significant increase on prior estimates.
Overall, during the period the research focused on, wildfires across the world contributed 10-15% of total GHG output. Many of these occurred in carbon-rich peatlands. This type of environment is found in 180 countries, and can store at least twice the quantity of carbon as any other vegetation, effectively representing the world’s largest carbon sink.
When this burns, CO2 is released along with other gases such as carbon monoxide and methane. The storage capability is also significantly reduced by many activities that support human development, with around 15% of all peatlands now thought to be irreversibly damaged or experiencing extreme degradation as a result of interference by people. The combined effect is that less emissions can be trapped, while some peatlands have become major sources of pollution themselves.
Measuring overall damage to the atmosphere caused by peatland fires is notoriously difficult. Primarily, blazes occur underground, making detection through satellite difficult. Adding to the problem, thick plumes of smoke generated further limit the ability to see what is happening on the ground. By using data based only on real-time measurements, most studies therefore offer a skewed picture of the extent of the impact.
‘Monitoring and measurement challenges in peatlands lead to an underestimation of the true impact of deforestation fires. Since these estimates form the basis of the policy response from national governments, it results in inadequate attention to forest and peatland protection as part of climate crisis mitigation efforts,’ said Dr. Ramanan Krishnamoorti, of the University of Houston, author of the study, which now calls for better mapping of peatlands and associated fires, and regular pre and post-fire ground work.
In related news, new research suggests around 43million people in the western US suffered the impact of harmful air pollution on a single day in 2020 due to wildfires.