The Sensitivity of Global Wildfires to Simulated Past, Present, and Future Lightning Frequency. Krause, A., Kloster, S., Wilkenskjeld, S., & Paeth, H. 119(3):312–322.
The Sensitivity of Global Wildfires to Simulated Past, Present, and Future Lightning Frequency [link]Paper  doi  abstract   bibtex   
In this study, components of the Max Planck Institute Earth System Model were used to explore how changes in lightning induced by climate change alter wildfire activity. To investigate how climate change alters global flash frequency, simulations with the atmospheric general circulation model ECHAM6 were performed for the time periods preindustrial, present-day, and three future scenarios. The effect of changes in lightning activity on fire occurrence was derived from simulations with the land surface vegetation model JSBACH. Global cloud-to-ground lightning activity decreased by 3.3\,% under preindustrial climate and increased by up to 21.3\,% for the RCP85 projection at the end of the century when compared to present-day, respectively. Relative changes were most pronounced in North America and northeastern Asia. Global burned area was little affected by these changes and only increased by up to 3.3\,% for RCP85. However, on the regional scale, significant changes occurred. For instance, burned area increases of over 100\,% were found in high-latitude regions, while also several regions were identified where burned area declined, such as parts of South America and Africa. [Excerpt: Conclusions] In this work we used components of the MPI-ESM to investigate the influence of climate change on global lightning activity and associated changes in burned area. We showed that ECHAM6, by using the parameterization of Price and Rind [1992], is able to simulate present-day global flash rates reasonably well, which is demonstrated by a correlation coefficient of 0.69 over land. Global annual total and CG lightning activity are projected to increase by 5, 13, and 31\,% and 3, 8, and 21\,% for the RCP26, RCP45, and RCP85 scenario, respectively, compared to PD. While absolute increases are greatest in the tropics, relative increases are most pronounced in northern North America and Asia. Flash frequencies over most maritime regions decrease with increasing temperatures. We found considerable changes in fire activity caused by changes in CG lightning frequency in many regions; however, these changes more or less even out on the global scale. The findings of Price and Rind [1994b] and Goldammer and Price [1998] that lightning-ignited fires will increase mostly in the tropics cannot be confirmed by our results, which show greatest increases in northern latitudes and a decline in many tropical areas. When we changed the forcing climate to RCP85, burned area increased by more than 44\,% for RCP85_PD and 49\,% for RCP85_RCP85 due to changes in fuel load, fuel moisture, and, for the latter, flash frequency. Thus, other impacts of climate change that control fire occurrence through changes in fuel availability and moisture on a global scale are significantly stronger than the lightning impact alone. In addition, our simulations also demonstrate that the impact of changing lightning activity on fire occurrence depends on the climate state. [] [...] While our study confirms that climate-induced changes in fuel availability and fuel moisture indeed outweigh the impact of changes in lightning ignitions on the global scale, we also show that changes in flash frequency significantly alter fire activity in many regions and should be accounted for in any future modeling studies dealing with burned area. [] However, our approach also suffers from several limitations. Lightning and fire are not completely understood, both processes are roughly parameterized in climate models and our ability to forecast lightning and fire in global warming scenarios is currently very limited [...]
@article{krauseSensitivityGlobalWildfires2014,
  title = {The Sensitivity of Global Wildfires to Simulated Past, Present, and Future Lightning Frequency},
  author = {Krause, Andreas and Kloster, Silvia and Wilkenskjeld, Stiig and Paeth, Heiko},
  date = {2014-03},
  journaltitle = {Journal of Geophysical Research: Biogeosciences},
  volume = {119},
  pages = {312--322},
  issn = {2169-8953},
  doi = {10.1002/2013jg002502},
  url = {http://mfkp.org/INRMM/article/14166881},
  abstract = {In this study, components of the Max Planck Institute Earth System Model were used to explore how changes in lightning induced by climate change alter wildfire activity. To investigate how climate change alters global flash frequency, simulations with the atmospheric general circulation model ECHAM6 were performed for the time periods preindustrial, present-day, and three future scenarios. The effect of changes in lightning activity on fire occurrence was derived from simulations with the land surface vegetation model JSBACH. Global cloud-to-ground lightning activity decreased by 3.3\,\% under preindustrial climate and increased by up to 21.3\,\% for the RCP85 projection at the end of the century when compared to present-day, respectively. Relative changes were most pronounced in North America and northeastern Asia. Global burned area was little affected by these changes and only increased by up to 3.3\,\% for RCP85. However, on the regional scale, significant changes occurred. For instance, burned area increases of over 100\,\% were found in high-latitude regions, while also several regions were identified where burned area declined, such as parts of South America and Africa.

[Excerpt: Conclusions]

In this work we used components of the MPI-ESM to investigate the influence of climate change on global lightning activity and associated changes in burned area. We showed that ECHAM6, by using the parameterization of Price and Rind [1992], is able to simulate present-day global flash rates reasonably well, which is demonstrated by a correlation coefficient of 0.69 over land. Global annual total and CG lightning activity are projected to increase by 5, 13, and 31\,\% and 3, 8, and 21\,\% for the RCP26, RCP45, and RCP85 scenario, respectively, compared to PD. While absolute increases are greatest in the tropics, relative increases are most pronounced in northern North America and Asia. Flash frequencies over most maritime regions decrease with increasing temperatures. We found considerable changes in fire activity caused by changes in CG lightning frequency in many regions; however, these changes more or less even out on the global scale. The findings of Price and Rind [1994b] and Goldammer and Price [1998] that lightning-ignited fires will increase mostly in the tropics cannot be confirmed by our results, which show greatest increases in northern latitudes and a decline in many tropical areas. When we changed the forcing climate to RCP85, burned area increased by more than 44\,\% for RCP85\_PD and 49\,\% for RCP85\_RCP85 due to changes in fuel load, fuel moisture, and, for the latter, flash frequency. Thus, other impacts of climate change that control fire occurrence through changes in fuel availability and moisture on a global scale are significantly stronger than the lightning impact alone. In addition, our simulations also demonstrate that the impact of changing lightning activity on fire occurrence depends on the climate state.

[] [...] While our study confirms that climate-induced changes in fuel availability and fuel moisture indeed outweigh the impact of changes in lightning ignitions on the global scale, we also show that changes in flash frequency significantly alter fire activity in many regions and should be accounted for in any future modeling studies dealing with burned area.

[] However, our approach also suffers from several limitations. Lightning and fire are not completely understood, both processes are roughly parameterized in climate models and our ability to forecast lightning and fire in global warming scenarios is currently very limited [...]},
  keywords = {*imported-from-citeulike-INRMM,~INRMM-MiD:c-14166881,~to-add-doi-URL,climate-change,global-scale,lightning,rcp26,rcp45,rcp85,vegetation,wildfires},
  number = {3}
}
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