Unprecedented Methane Emissions Drive the Amazon Toward Environmental Disaster
As global temperatures rise, methane released from thawing permafrost and warming tropical wetlands is accelerating climate change. However, mitigating these emissions is within our grasp. Addressing methane emissions offers our best opportunity to limit peak global temperatures in the coming decades, given that methane dissipates naturally from the atmosphere within about a decade. If we could eliminate all methane emissions from human activities, the concentration of this potent greenhouse gas could swiftly return to pre-industrial levels. Over the past two decades, humans have released over 3 billion tonnes of methane into the atmosphere. If we could suppress these emissions within the next 10 to 20 years, it would prevent an additional 0.5°C of warming. No other greenhouse gas offers such a powerful means of slowing the climate crisis.
Nevertheless, as the planet continues to warm, curbing emissions from human activities alone may not suffice. We might also need to address rising natural methane emissions, including those from warming tropical wetlands and thawing Arctic permafrost. The largest natural sources of methane emissions are tropical wetlands and seasonally flooded forests, like the Brazilian Amazon's Mamirauá Sustainable Development Reserve, which I recently visited. These emissions are expected to increase as temperatures rise. Tropical wetlands are particularly methane-rich because they are warm, wet (by nature), and low in oxygen—conditions that foster the growth of methane-producing microbes.
During my most recent trip to the Amazon last July, El Niño was gaining strength, and the tropical Atlantic was heating up. Ocean temperatures off Florida's coast approached a scalding 40°C (104°F), similar to the temperatures used to cook salmon, marking the highest surface ocean temperatures ever recorded. Warm waters in the tropical Atlantic often lead to droughts in the Amazon. While floating past trees during seasonal floods in the Mamirauá Reserve, Brazilian hydrologist Ayan Fleischmann, who directs climate research there, warned me of the impending drought. He noted that water levels hundreds of kilometers upriver in Tabatinga, Brazil, were already at record lows. Fleischmann's warning proved accurate, as by late September, the region was gripped by an unprecedented drought. Water levels in the Amazon system were the lowest in recorded history, and Brazil's Environment Minister, Marina Silva, remarked that the situation was a collision of two phenomena: the natural El Niño and human-induced climate change.
As temperatures around Mamirauá soared above 40°C, the absence of rain and clouds intensified the heat, cooking Amazon waters in the sun. In Lake Tefé, a gateway to the western Amazon, Fleischmann recorded water temperatures exceeding 40°C at depths of 3 to 6 feet. Speaking over Zoom a few days later, Fleischmann was distraught, recounting the horrifying sight of 70 river dolphin carcasses along the lake and a struggling dolphin swimming in circles. The combination of extreme heat and drought, along with over 7,000 fires raging across Amazonas state, had taken a severe toll. Traditional riverine communities, known as ribeirinhos, were also suffering, unable to reach hospitals or access food and water due to the low water levels.
Beyond tropical regions, Arctic tundra and peatlands also pose significant risks for methane emissions. Organic-rich peat accumulates in low-oxygen, waterlogged environments where microbial decomposition can't keep pace with new plant growth. Swedish scientist Gustaf Hugelius estimates that northern peatlands have stored at least 400 billion tonnes of carbon since the last ice age, equivalent to nearly half of all the carbon currently in our atmosphere. If permafrost thaws and Arctic and boreal soils warm, the carbon in peat could be released as carbon dioxide through peat fires or microbial decomposition. Alternatively, if the thawed peatlands become swampy, microbes could release much of the carbon as methane. Both scenarios would be devastating for the global climate, but the methane scenario would be catastrophic. It's likely that we'll experience a mix of both, with a slow start that may have already begun and will intensify over time.
In Finland, I recently participated in a peatland restoration project led by Tero Mustonen, co-founder and president of the Snowchange Cooperative. This global network of Indigenous cultures documents observations of the climate crisis across northern Canada, Scandinavia, Russia, and the US. Mustonen emphasized the critical role of snow and ice for life in the north, warning that climate change is hitting these regions harder than anywhere else, except possibly the Pacific. He recounted a journey along the East Siberian Sea coast, where he witnessed the massive melt of permafrost. "I saw collapsing permafrost walls and heard the coast slumping into the sea," he said, describing the unsettling experience of seeing ecosystems collapse over hundreds of miles. Determined to raise awareness of the crisis, Mustonen and Snowchange are not only sounding the alarm but also working to repair the damage.
A decade ago, the wetland I visited at Linnunsuo was an industrial wasteland, a legacy of peat mining for energy. Today, after extensive restoration efforts by Snowchange, the site has become a crucial stopover for more than 200 bird species during migrations. By flooding exposed peatland soils and adding limestone to reduce acidity, Snowchange has significantly reduced soil-based emissions, equivalent to taking 100,000 cars off the road each year. Their efforts illustrate how local landscapes and communities are adapting to the climate crisis, even as they acknowledge that these ecosystems will never return to their pre-industrial states.
What You Can Do: Cutting methane emissions can start at home. Replacing fossil gas with cleaner electric appliances and reducing beef and dairy consumption are effective steps. Heat pumps, for example, are two to three times more efficient than gas furnaces or boilers, making them a sensible choice for most homeowners, even in regions with relatively high electricity costs. I recently replaced my gas furnace and water heater with electric heat pump models, resulting in lower operating costs and zero greenhouse gas emissions when coupled with fossil-free electricity.
Gas stoves are another significant source of carbon dioxide and methane pollution. Studies in the US and UK have found that most methane emissions from gas stoves occur while they are off, due to leaky pipes and fittings. The steady release of methane from these sources is equivalent to the annual emissions of half a million cars. In addition to methane, burning gas indoors generates pollutants like carbon monoxide, benzene, and nitrogen oxides, which can linger at dangerous levels in homes.
Beyond changing how you cook, altering your diet can also reduce methane emissions. Cows, for example, emit a substantial amount of methane through burping and manure. Reducing beef and dairy consumption is another way to decrease your methane footprint and contribute to a healthier planet.