Carbon Sinks, Ecosystems Destroyed When Needed Most
From the Amazon to the Arctic, the last forests around the world are burning. Fueled by climate change, the wildfires are compounding the problem of global warming.
Carbon emissions from global wildfires reached record levels in August, after extensive blazes in Russia, California and Canada. Forest fires pump out black smoke, carbon dioxide, methane, and other harmful gases and particles. These toxic plumes can stretch for thousands of miles across the atmosphere. Smoke from blazes in California and Western Canada reached across the Atlantic Ocean, while the plume from Eastern Russia circled the Arctic.
Global warming and climate change are causing most of the fires. The fires are making the dynamics of global warming worse in several ways. One of the least discussed ways is the fact that black carbon emitted by fires darkens snow and ice as it settles to the ground. The darker complexion absorbs more light, which generates heat on the surface of the snow and ice. The added heat causes the snow and ice to melt faster. The Arctic is warming three times faster than the rest of the planet. As snow and ice melts, it exposes more rock or ocean below, which attracts even more light and produces even more heat.
“It is one of the more important Arctic feedback loops,” said Thomas Smith, associate professor in environmental geography at the London School of Economics.
As the Arctic warms, fire poses a greater risk for regions such as Russia’s Sakha Republic, which lies partly inside the Arctic Circle. This summer, smoke from Russian wildfires crossed the North Pole to reach Greenland and Canada.
“We know that climate change is playing a very important role in the Arctic, increasing the frequency of the fires, the size of the fires, and the intensity,” said LSE’s Smith. “One problem is that if the fires come more frequently, then the forest will not regenerate.”
“The Arctic climate is full of amplifiers like this — from increasing humidity, reduced reflective snow cover, increased heat input into the atmosphere from a more exposed ocean surface,” said Jason Box, professor of glaciology at the Geological Survey of Denmark and Greenland. “The extra black carbon emitted from the increasing high-latitude wildfires is fundamentally one of those amplifiers that increase the pre-existing warming effect from elevated carbon dioxide.”
Scientists named this atmospheric circulation pattern the circum-Arctic wave (CAW), as a driver for enhancing the co-occurrence of heatwaves in Europe and wildfires in Siberia and subpolar North America. According to the WMO, we can expect to see forests in the northern hemisphere burn like they never have over the past 10,000 years.
Catastrophic fires have been burning across Africa, the Amazon Basin, Indonesia, North America, Siberia and beyond for years now. Reckless energy policies and land use are to blame. Reversing the damage won’t be easy.
Although wildfires are a natural occurrence within some forest ecosystems, fire seasons are becoming more extreme and widespread, even in tropical rainforests where fires are devastating. Hotter, drier weather caused by climate change and poor land management create conditions favorable for more frequent, larger and higher-intensity wildfires. The majority of the fires in the Amazon and Indonesia are manmade and intentional—the result of illegal deforestation and clearing of farmland. In most cases, rainforests are burned down deliberately to create room for cattle, soybeans and palm oil plantations.
Large-scale clearing disrupts the very processes that give the rainforest its name—the ability to absorb, store, and recycle water as rainfall. It also destroys critical habitat and a vital carbon sink. As the soil dries out and tree cover is lost, the tropical forest becomes a tinderbox.
“This is one of the most traumatic things you can do to an ecosystem,” explained Nigel Sizer, a program officer with the Rainforest Alliance. The rainforest has no natural defense against fire.
In Brazil, corruption makes things worse. Scientists, NGOs and global leaders agree that the crisis is a political one. Since 2005, Brazil fought deforestation through monitoring and alert systems. Since Jair Bolsonaro became president, he has opened the rainforest for exploitation.
This year, scientists announced that the southeastern part of the Amazon has become a net carbon producer—meaning that it is emitting more carbon than it absorbs. Without new policies in Brazil and Bolivia, the rainforest could rapidly reach a point of ecological collapse. If tree loss passes the 20-25 percent threshold, the entire basin would lose its capacity to absorb carbon dioxide. The land would progressively turn into dry savanna like the neighboring cerrado. As with the thawing of Arctic permafrost, this would release billions of tons of carbon into the atmosphere, accelerating global warming and triggering a vicious cycle of rising temperatures and more fires. The crisis in the Amazon has been a powerful reminder to the entire world that we absolutely must keep forests standing if we are to stand a chance at stabilizing our climate.
Experts say high population density has led to increasingly intensive use of natural resources, meaning the ecosystems have less and less time to recover. And the fires are also becoming more common.
“The main reason for this is the widespread use of shifting cultivation,” explains Winter. “Landowners and farmers [use fire to clear] their fields to quickly get rid of vegetation and make the soil fertile in the short term.”
Even some of the small fires set by farmers get out of control, leading to larger wildfires. In addition to the forest fires, conventional farming methods not only degrade land—which reduces crop productivity over time—but also devastates surrounding ecosystems. Farmers also must maintain or establish zones of natural vegetation—known as riparian buffers—along the edges of rivers and streams. These zones help prevent pollutants from entering the waterways, with the added bonus of providing habitat for local wildlife. Protecting waterways protects downstream ecosystems, and eventually, the ocean.
Conserving forests could cut as much carbon dioxide each year as getting rid of every car on the planet. The best strategy to keep our forests standing is the cultivation of sustainable forest economies. Forests, especially tropical forests, are a critical part of the global climate solution. Without their carbon-storing potential, we cannot keep the Earth’s warming in check. Natural climate solutions can help us achieve 37 percent of our target emissions reductions, according to the UN Intergovernmental Panel on Climate Change (IPCC). To halt deforestation, all companies must build ethical supply chains and advance sustainability policies.
“We know what needs to be done, what works and how we can achieve results,” said Inger Andersen, the UN Environment Programme’s executive director.
Forest Fire Facts:
- Nearly half of the world’s rainforests have been destroyed since the 1960s;
- Every day, about 81,000 hectares (200,000 acres) of rainforest — an area nearly 14 times the size of Manhattan — are burned around the world;
- About 36 football fields worth of trees are lost every minute due to deforestation.
- About 96 percent of global forest fires are caused by humans, according to WWF;
- About 8 billion tons of CO2 are released by forest fires every year (about half as much as the burning of coal around the globe);
- More than 27 million hectares of forest have been destroyed for paper and palm oil industries since 1990, in Indonesia; and
- Approximately 73,400 square miles of Amazon rainforest have been impacted by fires, affecting 95 percent of all Amazonian species and as many as 85 percent of species that are listed as threatened in the region, since 2001.
