The team from the University of Edinburgh BRE Centre for Fire Safety and Engineering studied 200 million-year-old fossils of burnt plants from East Greenland, during a period with high levels of CO2 in the atmosphere and a warmer climate.
The warm climate caused plants to evolve from having thick to narrow leaves, which helped prevent them from losing water. Laboratory experiments have shown plants of this shape to be more flammable, and therefore prone to wildfires.
The study sheds light on how climate-driven changes in vegetation can cause increases in the flammability of plants. The research may help understanding of whether or not plant life could become more flammable based on global warming estimates.
Dr Guillermo Rein, of the University of Edinburgh's School of Engineering, said: "This research brought together scientists from very different backgrounds, and doing so has given us insights into ancient wildfires that we might otherwise not have had."