Australia wildfires long-term effects could contribute to even more extreme weather events
The ongoing bush fires in Australia are forever changing the landscape of the country. In the months since the fires started, more than 26 million acres of land has been scorched, more than 5,900 buildings — including over 2,200 homes — have been destroyed, at least 27 people have lost their lives, and more than one billion animals have perished because of the flames. While the immediate impact of these fires has been devastating, the long-term effects of Australia's inferno could be even worse. As Australia burns, massive amounts of carbon dioxide are being pumped into the atmosphere — and the flames are destroying parts of the planet that would typically capture those gases and prevent them from heating the planet.
While humans have been pumping an unprecedented amount of carbon and other greenhouse gases into the atmosphere by burning fossil fuels, forests have been some of the planet's best defenders against this behavior. Forests and similar habitats — everything from the trees to the soil to vegetation — are often considered to be carbon sinks, absorbing more carbon than they release. According to the United Nations' Food and Agriculture Organization, about 20 percent of carbon in the earth's biosphere is stored in plants, while the remaining 80 percent takes hold in soil. In forests, that balance shifts to 30 percent in biomass like trees and vegetation while 70 percent remains in the soil.
Forests are some of our most effective tools for sequestering greenhouse gases, though we've made their jobs increasingly hard through deforestation and land degradation, to the point that some forests have lost their ability to hold carbon effectively. But when these areas burn, the results are doubly harmful. Not only do large areas that keep carbon from entering the atmosphere go up in flames, but the burning process itself pumps carbon into the atmosphere. Scientists estimate that over the last 20 years, wildfires have accounted for about eight billion tons of carbon dioxide per year being put into the atmosphere. That's about one-forth of the 32.5 billion tons of CO2 emissions in 2017, according to the International Energy Agency (IEA).
However, as Inside Climate News notes, scientists usually don't include wildfires in net emissions calculations because the emissions are offset by forest growth that occurs after the burn. As a result, most estimates suggest wildfires make up about five to 10 percent of annual carbon emissions. This has become a point of contention for some scientists who believe this model of calculation is out of date. According to the BCC, some experts believe that wild fires actually account for closer to 30 percent of carbon emissions each year — and expect that figure to climb as the planet continues to warm and produces conditions that result in more frequent burns.
According to estimates published by Wired, the Australia wildfires have already released more than 350 million tons of carbon into the atmosphere. The fires are expected to continue to burn for the next couple months at least, as Australia's summer season carries on. Given the levels of unprecedented heat that have already been experienced in the country, in addition to ongoing droughts that show no signs of stopping, it seems likely that the country will suffer from an unseasonably warm period that will serve to exacerbate the flames rather than help fight them. The resulting release of carbon will be hard to overcome.
According to a study published in Nature Geoscience last year, carbon released by wildfires like the ones happening in Australia can stick around in the atmosphere for centuries or even millennia. The reason: it takes a long time for the destroyed ecosystems to recover from the events. Typically, burns are a part of the natural cycle of a vegetated area. Fires occur, burn off the excess, and the area continues to grow, trapping the carbon released from the burn in the process. But with wildfires that rage out of control, the recovery period can take tens — if not hundreds — of years. It's also worth noting that while a typical burn results in the same vegetation returning, this doesn't always happen after a wildfire. It's harder to predict what kind of vegetation will take hold after a huge swath of land ends up scorched, according to Wired, which means the resulting ecosystem could have a considerably different make up — and carbon sequestering abilities — than what was there before. There is no tool for making up for what was lost, meaning the carbon released from the fire simply remains in the atmosphere, contributing to the warming of the planet until the ecosystem finally has time to rebuild itself.
That unchecked carbon pumped into the atmosphere will likely have adverse effects for the rest of the planet. While it's hard to say that climate change is responsible for any one weather event, it is not hard to see the increased global temperature — caused by human-made greenhouse gas emissions getting trapped in the atmosphere — is making some weather events worse. According to the Fourth National Climate Assessment (NCA4) produced by the U.S. Global Change Research Program (USGCRP), heat waves have gotten hotter and more common in recent decades. While cold days have gotten less common over the same period of time, they have also gotten more extreme, resulting in devastating weather events like the Polar Vortex. Similarly, the increase in global temperature has created conditions that make hurricanes more dangerous, allowing for faster wind speeds, heavier rains, and worse storm surges that result in more destruction. Wildfires burn longer due to heat and drought, also linked to climate change. Essentially, every weather event is intensified as the planet's temperature climbs so even if a storm isn't caused by climate change — as in, it wouldn't have happened at all without the temperature rise — it is made worse. Last year, Carbon Brief studied more than 230 extreme weather events and found as many as 68 percent of them were made more severe by human-caused climate change.
When fires like those burning in Australia occur, we shouldn't just look at them as a result of climate change — though they certainly are exacerbated by conditions that happen because of the global temperature rise. We should also view them as potential contributors to future extreme weather events. With every additional ton of carbon pumped into the atmosphere by the flames, we're also watching some of our best defenders against excess carbon go up in smoke. Protecting these areas rather than destroying them through deforestation would go a long way to help the planet's long-term health. Failing to do so could mean seeing these types of devastating, destructive forces more often.