The Finnish company Hiiliporssi Oy (the Carbon Exchange) promises that restoring peatlands will have a beneficial effect on the climate. A study by Luke (the Natural Resources Institute Finland), on the other hand, found that peatland restoration contributes to global warming. Both claims are true, but they are assessed over different time periods.
Founded by the Finnish Association for Nature Conservation and now operating independently, Hiiliporssi Oy raises money to restore drained peatlands, promising climate benefits as well.
A recent Luke study found that restoring forested mires to open habitat will warm the climate over a period of up to a hundred years.
Reading this, it would seem that the promises made by Hiiliporssi Oy contradict the latest research. According to Risto Sulkava, the company's peatland expert, there is no contradiction, because the two are talking about two different time periods.
Luke looked at the fast-cycling carbon bound up in trees. It moves cyclically between plants and the atmosphere over a period ranging from a single year to a few centuries. The carbon captured in trees therefore does not reduce the amount of carbon in the atmosphere, because the same quantity of wood decomposes or burns just as it grows – over a century or longer.
Carbon that is transferred into peat, by contrast, is removed from the atmosphere and cools the planet. The carbon held in peat is on its way from the atmosphere, through plants and the peat layer, into the earth's crust. In this long cycle the carbon remains locked away for thousands or millions of years.
Methane emissions are a short-term problem
Risto Sulkava acknowledges that the peatland restoration process releases methane, which warms the atmosphere, but argues that this should only be regarded as a problem for the first few years after restoration. Methane is a short-lived greenhouse gas that is released and breaks down in equal measure after the first ten years.
According to Sulkava, methane emissions can be reduced if, when the ditches are filled in, the groundwater level is not allowed to rise as far as the surface of the moss layer, with the water remaining 5-15 cm below it.
“In that case the symbiotic bacteria living in the moss cells take up the methane and use it for their own life processes.”
Sulkava also points to the carbon that ends up in water bodies. In his words, greenhouse gas calculations do not include the impact on water bodies that are drained and from which large amounts of humus, organic matter and nutrients leach away. Finnish lakes release far more methane than Canadian lakes, the professor noted.
In the view of Paavo Ojanen (one of the authors of the Luke peatland restoration study at the Natural Resources Institute Finland), there is no substantial contradiction between the institute's research and the claims made by Hiiliporssi Oy.
“The carbon that enters the water is included in the greenhouse gas calculations, on the assumption that most of the carbon from water bodies reaches the atmosphere. The effect of the type of land use on methane emissions is, however, very difficult to assess.”
About Hiiliporssi Oy
Hiiliporssi Oy (the Carbon Exchange) is an independent limited liability company set up by the Finnish Association for Nature Conservation, which collects funding from businesses and other organisations for peatland restoration.
Risto Sulkava is the chair of the company's board and Heikki Susiluoma is its chief executive; both have served as chairs of the Finnish Association for Nature Conservation.
The company's turnover in 2021 was 7,000 euros, rising the following year to 141,000 euros. According to the most recent financial statements, its turnover has fallen to 55,000 euros.