Though temperatures have cooled somewhat in Australia, providing much-needed relief for the overworked and exhausted firefighters, provides some critical time to strengthen containment lines the firestorms have not stopped. They are predicted to intensify in the next few days as yet another heatwave will desiccate the soils, plants, and trees of Australia to tinder.
Many scientists now believe some of the planets forests may never recover. If the forests somehow can defy all odds in an increasingly warming world, it still may take burned forests around the globe decades to recover. Those are decades that we don’t have to save ourselves from the worst impacts of the climate crisis.
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.
“It’s likely the forests won’t be coming back as we know them.”
The Australian bushfires were exacerbated by two factors that have a “well-established” link to climate change: heat and dry conditions, says Stefan Rahmstorf, department head at the Potsdam Institute for Climate Impact Research in Germany and a lead author of the United Nations’ Intergovernmental Panel on Climate Change’s Fourth Assessment Report.
In recent years, Australia has experienced long-term dry conditions and exceptionally low rainfall. Scientists say that droughts in the country have gotten worse over recent decades. At the same time, the country has recorded record high temperatures; last summer was the hottest on record for the country.
“Due to enhanced evaporation in warmer temperatures, the vegetation and the soils dry out more quickly,” says Rahmstorf. “So even if the rainfall didn’t change, just the warming in itself would already cause a drying of vegetation and therefore increased fire risk.”
Australia: you have just experienced the future. pic.twitter.com/5H0ab4tMzJ
— Ed Hawkins (@ed_hawkins) January 6, 2020