Earlier this year, an important article by Pascual et al. was published in Science, one of the world’s most respected scientific journals. They compare Swedish primeval and natural forests with managed forests and conclude that if you add up all the carbon stored in the forest and its products – living vegetation, dead wood, soil, and in the harvested tree trunks – the primeval and natural forests store about 72% more carbon than the managed forest. The news reports were usually about the conclusion that “forestry has emitted more carbon dioxide than Sweden’s total fossil emissions since the industrial revolution”. But there are also other things to highlight in the researchers’ results: for example, how the calculations contradict the forest industries’ arguments that wood products in wooden houses and other products store carbon and that it would therefore be climate-smart to harvest and manage the forest
The article makes it clear that even if you add up the carbon in all dead wood in a managed forest with all the carbon stored in wood products from it, the sum is still lower than just the dead wood in the corresponding natural forest. And the dead wood is only 6% of the total carbon sequestration in a natural forest! The fact that the wood “lives on” as carbon in buildings and furniture does not compensate for even this small part, let alone for the much larger differences in soil carbon and living biomass between natural forests and managed forests, as the article describes.
According to the industry association Svebio’s calculations, which are in line with Protect the Forest’s own calculations, almost four-fifths of the harvested volume is turned into short-lived products, such as cartons, direct mail and biofuel. All of this is soon released back into the atmosphere: the fuel is burned, and the cartons become garbage that is burned and turned into carbon dioxide. But the researchers are conducting a thought experiment to the maximum advantage of the forest industry: assume that we in Sweden radically switched our entire wood product mix to long-lived products, such as particle board for house construction.
They then arrive at a clear limit for how much of the difference in stored carbon can be recovered through storage in long-lived wood products. With today’s product mix, Swedish wood products store 0.61 kg of carbon per square meter, which covers just under half of the difference in dead wood between natural forest and managed forest. But even in the researchers’ maximum scenario, where all the wood that today goes to paper and energy was instead used in long-lived materials, the storage would stop at 1.94 kg. This is enough to compensate for the carbon dioxide loss in dead wood when the natural forest was felled, but this is only about 20% of the total carbon difference between natural forest and managed forest. The rest consists of soil carbon and living biomass and thus cannot be stored in a building, as it is emitted during felling.
So while the forest industry claims that it is “climate-smart” to manage the forest as hard as possible, this article says that by far the most climate-smart thing is to leave our last remaining natural forests standing. Something that is of course also incomparably better for biodiversity.
This is a solid, well-conducted study whose results have already been cited by a dozen other researchers and have not met with any significant criticism from the scientific community. The study has been commented on in popular science contexts: Michael Gundale, professor at SLU’s Department of Forest Ecology and Management, argues in Research & Progress that the difference between natural forest and managed forest may be somewhat overestimated, especially in soil carbon, but does not question the study’s overall conclusions; Martin Forsius, research professor at the Finnish state institute SYKE, makes a similar assessment in the Finnish forest owner movement’s magazine. Björn Lindahl, professor of soil science at SLU, and Line Nybakken, professor at the Norwegian University of Life Sciences, assess the study as “well-done and convincing” and “important and impressive”, respectively.
Sources:
Pascual et al., Higher carbon storage in primary than secondary boreal forests in Sweden, Science 391, 1256 (19 March 2026), DOI: 10.1126/science.adz8554.
Old-growth forests store significantly more carbon than managed forests – Research & Progress, 19 March 2026 (Gundale, Lindahl)
How much more carbon is taken up by primeval forests – forskning.no, 28 March 2026 (Nybakken)
Hiili kertyy lahopuihin ja maaperään vanhoissa metsissä – Maaseudun Tulevaisuus, 10 April 2026 (Forsius)