Global warming and land use change are bringing peatlands, the largest carbon reservoirs on the planet, to the brink of collapse. Several scientific studies have confirmed the progressive destruction of peat bogs in the Amazon and permafrost in northern Europe and Western Siberia. Although they only cover less than 4% of the earth’s surface, these ecosystems store half of the Earth’s carbon, more than the biomass of all existing forests. So that if its content were released, the amount of carbon on the planet would double and the consequences would be disastrous.
The peat bog is a type of acid wetland in which a large amount of organic matter accumulates in the form of peat. They are like sponges of moss and vegetation that have accumulated over thousands of years without completely decomposing, in an environment saturated with water. They account for 50% of the world’s wetlands and can be found on all five continents.
These ecosystems are highly vulnerable to human intervention and are at risk of disappearing.: In Europe, Asia and America peats are drained to generate more land for agriculture and forestry. The problem is that when they are drained and the peat decomposes, carbon is released into the atmosphere.
The Food and Agriculture Organization (FAO) of the United Nations calculates that due to the drainage of peatlands (15% of all existing ones in the world have already been drained) about a gigaton of greenhouse gas emissions are being released each year.
fire prone areas
An international scientific team has carried out a study focused on the Peruvian Amazon and has verified that the change in land use is causing the loss of large areas of peat bogs, which is associated with substantial greenhouse gas emissions (GHG).
The researchers, who have just published their study in the journal ‘Nature Geoscience’, call for the design of effective policies for the conservation and restoration of peat bogs, an objective for which location maps and carbon storage of these tropical ecosystems are vital.
In the Peruvian Amazon alone, peat bogs occupy more than previously believed, between 62,000 and 67,000 square kilometers, double that of Catalonia (32,113 square kilometers), and store some 5,400 million tons of carbon. It is double what was previously calculated and as much as all the forests in Peru, but concentrated in only 5% of the land area of the country.
The research, directed by the Universities of Edinburgh and Saint Andrews and with the participation of scientists from the Peruvian Amazon Research Institute in Peru, has confirmed increasing areas of deforestation and CO2 emissions associated with peat decomposition due to conversion to mining, urban areas and agriculture.
The study’s authors suggest tailored monitoring, protection and sustainable management of tropical peatlands “to prevent further degradation and CO2 emissions.”
Drained peatland areas are prone to fire, which can lead to a large and rapid increase in emissions. In recognition of these threats, Peru has passed legislation that for the first time mandates the explicit protection of its peatlands for climate change mitigation.
Very pessimistic climate projections
“Peatlands store half of all the soil carbon on the planet, but they are vulnerable to human pressures. It is important for all of us to know where they are so we can protect them and help mitigate climate change. There is still a lot to learn”, says Ian Lawson, leader of the international project.
But permafrost peatlands are also close to the climate tipping point. The frozen peatlands in these areas of Europe and western Siberia store up to 39.5 billion tons of carbon, twice the amount stored in European forests as a whole.
A study led by the University of Leeds and published last March used the latest generation of climate models to examine the possible future climates of these regions and the possible impact on their permafrost peatlands.
The projections are very pessimistic: Even with the greatest efforts to reduce global carbon emissions and limit global warming, by 2040 northern European climates will no longer be cold and dry enough to support peat permafrost..
Nonetheless, strong action to cut emissions could help preserve suitable climates for permafrost peatlands in northern Western Siberia, a landscape that contains 13.9 billion metric tons of peat carbon.
The study, published in ‘Nature Climate Changand‘, emphasizes the importance of socioeconomic policies aimed at reducing emissions and mitigating climate change and its role in determining the rate and extent of thawing of permafrost peatlands.
“We must not throw in the towel”
“Our study shows that these fragile ecosystems are on the edge of the precipice and even moderate mitigation leads to widespread loss of climates suitable for peat permafrost by the end of the century”, indicates Richard Fewster, researcher at the Leeds School of Geography and lead author of the study.
Fewster, however, left a door of hope open: “That doesn’t mean we should throw in the towel.. The speed and extent to which suitable weather is lost could be limited, and even partially reversed, by strong climate change mitigation policies”.
“The magnitude of 21st century climate change is likely to outweigh any protection that the insulating properties of peat soils may provide,” he adds.
The large amounts of carbon stored in the permafrost soils of peatlands are particularly threatened by rapid climate change. When permafrost thaws, organic matter begins to break down, releasing greenhouse gases like carbon dioxide and methane, which increase global temperatures and potentially accelerate global climate change.
Amazon Peatlands Study: https://www.nature.com/articles/s41561-022-00923-4
Permafrost Peatlands Study: https://www.nature.com/articles/s41558-022-01296-7
Environment section contact: email@example.com