Despite California’s inferno, global wildfires are fizzling out

PARADISE, A SMALL Californian town, looks like hell. Some 80-90% of its homes have been incinerated by the state’s deadliest-ever wildfire, which so far has killed 48 people and left over 200 missing (see United States section). Measured by area burned, nine of California’s ten worst recorded fires have occurred since 2000.

President Donald Trump says that poor forest management is the sole cause of the blaze. Scientists beg to differ. John Abatzoglou and Park Williams, two academics, have shown that temperature and dryness exacerbate wildfires in the western United States. Without global warming, they reckon, only half as much woodland would have burned between 1984 and 2015.

America is not the only rich country in danger. Since 2016 Portugal and Greece have suffered their most lethal wildfires in history, killing over 200 people. One study found that if global temperatures reach 3°C above pre-industrial levels, the area burned in southern Europe would double.

Yet despite the attention paid to such disasters, their rising frequency in parts of the West is an exception to the global trend. Most wildfires occur in developing countries, where they are declining. According to Niels Andela of NASA, the world’s total area on fire fell by 24% from 1998 to 2015.

Two main reasons are agriculture and stronger property rights. Two-thirds of the world’s burned area is in Africa, a dry, hot continent where pastoralists have often used fire to clear land. Slash-and-burn methods remain common in parts of Asia as well. The growth of modern farming is helping to put blazes out: dividing land into pastures and fields breaks up terrain and makes it harder for infernos to spread. Settled people who have things to lose prefer fighting fires to starting them.

This trend is so robust that fire is expected to keep fizzling out. Across various scenarios of global warming and population growth, Wolfgang Knorr of Sweden’s Lund University finds that the fire-reducing impact of changing land use generally outweighs the effect of rising temperature.

This will save lives. Wildfires cause 330,000 premature deaths a year by spewing smoke, far more than by trapping victims. People moving onto fire-prone land put themselves at risk. But by keeping flames in check, they make the air more breathable for everyone else.