Wild guess

Despite being a significant source of greenhouse gases, wildfire emissions remain underestimated

- ROHINI KRISHNAMURTHY

IF THE area that gets affected by wildfires each year were considered a country, it would be the second largest emitter of carbon dioxide (CO2), surpassed only by China. In 2023, wildfires globally released 7,330 million tonnes of CO₂, according to the EU's Copernicus Atmosphere Monitoring Service (CAMS). This is significantly higher than the 6,000 million tonnes of greenhouse gases (CO, and other gases) emitted by the US in 2022 (see 'Big emitters', p18).

This year, as many as 11 countries have reported wildfires as of May 15. In Canada, home to 9 percent of the world's forests, significant fires were reported as early as May 9, leading to evacuation orders in several towns in British Columbia and Alberta provinces. By mid-May, an estimated 55 million tonnes of CO2 (MtCO2) had already been released into the atmosphere from these fires, according to CAMS. The May 2024 North American Seasonal Fire Assessment and Outlook, issued by government agencies in the US, Canada and Mexico, highlights that the current warm, dry, and windy conditions could trigger additional wildfires.

This raises concerns that the 2024 Canadian wildfires could follow the path of the record-breaking 2023 event, which destroyed 18.4 million hectares an area bigger than Greece and released 1,760 MtCO2.

The actual wildfire emissions could be even higher because calculating them is challenging and "probably underestimated," says Cynthia Whaley, a researcher at Environment and Climate Change Canada, a government department that coordinates the country's environmental policies.