Decreasing causal impacts of El Niño-Southern Oscillation on future fire activities

Sci Total Environ. 2022 Jun 20:826:154031. doi: 10.1016/j.scitotenv.2022.154031. Epub 2022 Feb 24.

Abstract

Wildfires alter the composition and structure of ecosystems and result in huge economic costs. While future fires and ecosystems recovery might become increasingly challenging to manage under warming environment, further understanding of the main drivers of wildfires is necessary. The El Niño-Southern Oscillation (ENSO) is a major climate mode and is expected to affect global wildfires. Nevertheless, there is uncertainty regarding the causal impacts of ENSO on future fire activities at the global scale. Here we use model outputs from the Coupled Modeling Intercomparison Project Phase 6 to systematically evaluate the response of future fire activities (i.e., fire carbon emissions) to ENSO during the period 2015-2100 over different continents. Our results demonstrate that the impacts of ENSO on fires are found in the tropical and subtropical regions of Africa, Asia, Oceania, and America, while ENSO impacts over high latitude regions are very limited over Alaska and far eastern Europe. We showed that the role of ENSO on fire activities over subtropical regions might be more important than previously understood. High consistency between models is observed for the impacted regions. In historical experiment, the areas with significant ENSO effects on wildfires account for approximately 5.85% of land-area and this ratio decreases to approximately 5.39% and 2.92% of land-area in the future scenarios SSP2-4.5 and SSP5-8.5, respectively. These results imply a decrease in ENSO impacts on global fire activities in future projections compared to the historical period 1915-2000. This work might contribute to the ENSO-based forecasts of global fire activities.

Keywords: CMIP6; Causal effects; El Niño–Southern Oscillation; Fire carbon fluxes; Future projections; Wildfires.

MeSH terms

  • Africa
  • Asia
  • Ecosystem
  • El Nino-Southern Oscillation*
  • Wildfires*