Despite increasing in surface area, European forests store less carbon than they did 250 years ago, leaving a carbon debt of 3.1 petagrams of carbon (11.4 billion tonnes of CO2), a recently published article in Science Magazine claims.
Between 1750 and 1850, Europe’s forests grew in area by 196,000 km2. Yet size isn’t everything. The article indicates that, although Europe now has more forests, these are far from their potential carbon-carrying capacity. It queries whether European forest management practices are fit for fighting global warming, and suggests the carbon debt comes from two main factors.
First, replacing broad-leaved forests with coniferous forests that do not lose their needles in winter darkens the landscape, meaning less of the sun’s radiation is reflected. Second, increasing management in forests leads to a lower carbon stock in living biomass, coarse woody debris, litter and soil.
The article comes at an interesting time: European policymakers are due to publish a decision on LULUCF (Land Use Land Use Change and Forestry) as part of the climate and energy package for the period 2021 - 30. The article has a key message for the LULUCF debate: simply encouraging afforestation is not enough to increase the role that European forests play in tackling climate change; managing forests in such a way that allows them to recuperate lost carbon is also critical.
The EU is also currently consulting on sustainable bioenergy policy that is relevant for ensuring forests are fit to mitigate climate change. The renewable energy sector is one of the causes for the declining forest sink that is projected between 2020 and 2030.
Sustainable bioenergy criteria could help limit the pressure on the EU’s sink if they ensured that wood is used in a resource-efficient manner, i.e., only burned as a last resort after it has been used elsewhere in the value chain, thus genuinely contributing to mitigating climate change.
The criteria must also ensure that bioenergy demand does not lead to reduced levels of , coarse woody debris and litter in forests, which, as Science Magazine indicates, significantly decrease forests’ overall carbon storage and mitigation capacity.
Image: Liga Eglite via Flickr