An average of 3.5m square kilometres of land go up in smoke each year as a result of wildfires. Annual carbon dioxide released in these infernos can exceed half the emissions from humans burning fossil fuels.
A new study finds that the number of days wildfires are likely to burn each year is increasing as global temperatures rise.
Researchers estimate that between 1979 and 2013, the wildfire season has lengthened by an average of 19% for more than a quarter of the Earth’s vegetated surface.
Weather and wildfires
From the 600 fires that claimed more than 50 lives in Russia in 2010, to the series of major bushfires in Australia in 2013 that caused $9.4bn of damage, wildfires affect much of the world’s surface.
Wildfires play an important role in flammable ecosystems, such as forests, grasslands, savannas, and shrublands. They can be managed to disperse plants, clear forests and promote grazing, or suppressed to protect human lives and property.
Most wildfires are triggered by humans – as much as 90% in the US, for example – while natural causes include lightning and lava. But the weather is the biggest driver of how much area that wildfires actually burn. Temperature, humidity, rainfall and wind speed all play a role in providing the right conditions for a fire.
A new study, published in Nature Communications, finds that changes in these different weather variables are conspiring to increase the risks of wildfires.
Press link for more: Robert McSweeney | carbonbrief.org