In a paper published in Nature Climate Change this week, Sander Veraverbeke from the Vrije University in the Netherlands found that lightning ignitions were responsible for a record number of fires in the Northwest Territories and Alaska during 2014 and 2015. A unique feature of these fire extremes was their close proximity to northern treeline. Sander was also able to demonstrate that lightning ignitions were linked to summer temperatures over the past decade, and that lightning explained a considerable amount of the year-to-year variability in burned area and fire emissions in these regions. Although it has been well recognized that warmer temperatures increase the amount of burning and also likely increase the severity of fires, the link between climate and lightning was a novel element of Sander’s study. The study also describes the potential for a positive feedback loop in which climate warming allows lightning to move farther north, sparking fires in arctic tundra. An increase in arctic fire, in turn, may allow trees to migrate northward faster, which will further enhance atmospheric heating and lightning ignition in a positive feedback loop. This amplification loop is important because arctic tundra covers vast reservoirs of permafrost carbon that may become vulnerable once fires consume moss layers on the surface that act to insulate frozen carbon from climate warming. Coverage on the study included news reports in Scientific American and National Geographic. Sander is a former UCI project scientist, and co-authors on the study include UCI Ph.D. student Elizabeth Wiggins and former Ph.D. student Brendan Rogers.