The secret to climate smart forestry
Managed forests with high growth are better for the climate than unmanaged forests. This is the conclusion of an analysis by researchers at the Swedish University of Agricultural Sciences (SLU) within the framework of the Future Forest research programme.
Manage the forest, increase forest growth and use the forest raw material to manufacture products that can replace those that damage the climate. This is an effective way of getting the best climate benefit from our forests, according to Tomas Lundmark, professor at SLU and participant in Future Forest.
Tomas Lundmark adds that, in their study, the SLU researchers have not only analysed how much carbon is stored in forests and land. To place the climate-related role of forestry in a wider context, the researchers also calculated the climate effects that the products from the managed forests generate. The impact is significant, since many such products and fuels replace fossil-based or more energy-intensive alternatives. Today’s forestry already has a major beneficial effect on the climate. If we didn’t have access to all the forest’s products, emissions of carbon dioxide in Sweden would be substantially higher than they are at this time.
“It’s important for us to reduce our reliance on oil, coal and natural gas as quickly as possible. The forest can help in many ways, not least by delivering more raw material for climate-smart products such as bio-based fuels, wood for construction and packaging for food,” says Tomas.
The researchers also analysed what happens if you choose not to manage the forest, and leave it to grow freely instead. In the short term this may help to slow the rising levels of carbon dioxide in the atmosphere due to all the carbon storage that occurs in the growing forest. There is, however, a limit to how long this beneficial effect can last. When the forest reaches a certain age, the growth tails off and so does the carbon storage effect. Old and dense forest that is left to its own devices also risks being hit by storms and fires, which leads to significant carbon emissions.
Holmen's forests capture 4 350 000 tonnes carbon dioxide every year.
Tomas Lundmark emphasises that, whether one chooses a strategy of storing carbon in the forest or using forest raw material to replace fossil carbon and so reduce net emissions of carbon dioxide, the growth of the forest is the critical factor. The higher the growth, the greater the potential benefits for the climate.
“If we started managing our forests in a way that boosted growth by 40–50 per cent and used the greater supply of raw material cleverly, Sweden could actually achieve net carbon emissions of zero in the future. Such an increase in growth is not unrealistic over the long term, but it would require clearer forest policy objectives than the ones we have today,” says Tomas.
“Holmen makes a positive contribution to the climate”
The study by the SLU researchers shows that Sweden’s forests, forestry and forest industry play a vital role when it comes to the climate. And Erik Normark, head of R&D at Holmen Skog, is positive that the climate benefit could be even greater in the future.
Holmen’s forests capture over 600 000 tonnes of carbon dioxide per year through their growth. In a broad study of the Group’s environmental impact, this positive effect has been added to the climate effects of the products and weighed against the emissions that occur during production.
“The calculations show that, overall, Holmen’s operations have a positive impact on the climate. This is because of the carbon dioxide that is captured and stored in our forests and in the sawn timber that is produced. The fact that our products replace others that are harmful to the environment is also a significant plus,” says Erik Normark.
Holmen aims to increase forest growth by 25 per cent by 2050, which will lead to even more carbon being captured and stored in the forest.
“Raising our ambitions for our regeneration work, using the best seedlings and creating vigorous young forest will allow even more carbon dioxide to be captured. Higher growth also means that the production of climate-smart forest products can be increased. These benefits for the climate would naturally be lost if we didn’t manage the forests,” concludes Erik.
Tomas Lundmark, professor at SLU and participant in Future Forests.
Erik Normark, head of R&D at Holmen Skog.
The trees constantly capture carbon dioxide, but how much depends on their age:
Seedlings and forest up to 20 years old As the trees grow, they absorb relatively little carbon dioxide.
Young and middle-aged forest 21– 80 years old This is when the trees grow at their fastest and absorb the most carbon dioxide.
Old forest (over 90 years old) Trees of this age see a drop in their growth rate and ability to capture carbon dioxide.
Source: 5 truths about paper and the environment