Abstract
Lightning-induced fire is the primary disturbance agent in boreal forests. Recent large fire years have been linked to anomalously high numbers of lightning-caused fire starts, yet the mechanisms regulating the probability of lightning ignition remain uncertain and limit our ability to project future changes. Here, we investigated the influence of lightning properties, landscape characteristics, and fire weather on lightning ignition efficiency - the likelihood that a lightning strike starts a fire - in Alaska, United States of America, and Northwest Territories, Canada, between 2001 and 2018. We found that short-term fuel drying associated with fire weather was the main driver of lightning ignition efficiency. Lightning was also more likely to ignite a wildfire in denser, evergreen forest areas. Under a high greenhouse gas emissions scenario, we predicted that changes in vegetation and fire weather increase lightning ignition efficiency by 14 ± 9% in Alaska and 31 ± 28% in the Northwest Territories per 1 °C warming by end-of-century. The increases in lightning ignition efficiency, together with a projected doubling of lightning strikes, result in a 39%-65% increase in lightning-caused fire occurrence per 1 °C warming. This implies that years with many fires will occur more frequently in the future, thereby accelerating carbon losses from boreal forest ecosystems.
| Original language | English |
|---|---|
| Article number | 054008 |
| Pages (from-to) | 1-13 |
| Number of pages | 13 |
| Journal | Environmental Research Letters |
| Volume | 17 |
| Issue number | 5 |
| DOIs | |
| Publication status | Published - 19 Apr 2022 |
Bibliographical note
Funding Information:This work was carried out under the umbrella of the Netherlands Earth System Science Centre (NESSC). This project has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie, Grant Agreement No. 847504. We would like to thank Environment and Climate Change Canada and Vaisala for their generous permission to use Canadian Lightning Detection Network data. We acknowledge the World Climate Research Program’s Working Group on Coupled Modelling, which is responsible for the Climate Model Intercomparison Project, and we thank the climate modelling groups for producing and making their model output available. Thanks to S Bhattacharjee, kiddo, K Shastry, and W Buning for the freely available icons used. T D H wishes to thank J Steijn for discussion and improvement of the penalized ridge logistic regression and T A J Janssen for valuable input to the inclusion of ERA5 data.
Publisher Copyright:
© 2022 The Author(s). Published by IOP Publishing Ltd.
Funding
This work was carried out under the umbrella of the Netherlands Earth System Science Centre (NESSC). This project has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie, Grant Agreement No. 847504. We would like to thank Environment and Climate Change Canada and Vaisala for their generous permission to use Canadian Lightning Detection Network data. We acknowledge the World Climate Research Program’s Working Group on Coupled Modelling, which is responsible for the Climate Model Intercomparison Project, and we thank the climate modelling groups for producing and making their model output available. Thanks to S Bhattacharjee, kiddo, K Shastry, and W Buning for the freely available icons used. T D H wishes to thank J Steijn for discussion and improvement of the penalized ridge logistic regression and T A J Janssen for valuable input to the inclusion of ERA5 data.
| Funders | Funder number |
|---|---|
| Horizon 2020 Framework Programme | |
| H2020 Marie Skłodowska-Curie Actions | 847504 |
Keywords
- boreal forest fires
- climate feedback
- climate warming
- lightning ignition
- lightning ignition efficiency
