Extreme climate sparks record boreal wildfires and carbon surge in 2023

While human activities, such as the burning of fossil fuels, are the primary contributors to the increase in atmospheric CO2 levels, large-scale wildfires can exacerbate this situation. In years with extensive and severe wildfires, additional carbon emissions can significantly perturb global carbon budgets, thereby impeding existing endeavors to mitigate climate change. Notably, a recent investigation reported a notable surge in carbon emissions originating from boreal forests in 2021,2 reaching an estimated 0.48 gigatons of carbon (Gt C). However, this record proved temporary. Figure 1 shows that by September 2023, the carbon emissions of boreal forests exhibited an unprecedented increase, primarily attributed to the Canadian boreal region, reaching 0.86 Gt C. The consequences extend beyond geographical borders, as wildfires occurring hundreds of kilometers away resulted in the worst air quality in New York and Chicago. The increasing severity of boreal forest wildfires is accompanied by growing public concern, suggesting the potential proximity to or crossing of a critical tipping point in the ecological functioning of boreal forests.