In Australia’s burning forests, signs we’ve passed a global warming tipping point
As extreme wildfires burn across large swaths of Australia, scientists say we’re witnessing how global warming can push forest ecosystems past a point of no return.
Some of those forests won’t recover in today’s warmer climate, scientists say. They expect the same in other regions scarred by flames in recent years; in semi-arid areas like parts of the American West, the Mediterranean Basin and Australia, some post-fire forest landscapes will shift to brush or grassland.
More than 17 million acres have burned in Australia over the last three months amid record heat that has dried vegetation and pulled moisture from the land. Hundreds of millions of animals, including a large number of koalas, are believed to have perished in the infernos. The survivors will face drastically changed habitats. Water flows and vegetation will change, and carbon emissions will rise as burning trees release carbon and fewer living trees are left to pull CO2 out of the air and store it.
In many ways, it’s the definition of a tipping point, as ecosystems transform from one type into another.
The surge of large, destructive forest fires from the Arctic to the tropics just in the last few years has shocked even researchers who focus on forests and fires and who have warned of such tipping points for years.
The projections were seen as remote, “something that would happen much farther in the future,” said University of Arizona climate scientist David Breashers. “But it’s happening now. Nobody saw it coming this soon, even though it was like a freight train. [Continue reading…]