Satellite images have revealed a dramatic increase in the harvested forest area in Europe after 2015, according to a new study by the European Commission published on 1 July in the journal Nature (1). This could threaten the EU’s ambitious goal of reaching climate neutrality by 2050 and highlights potential problems with current forest management strategies.
The researchers from the European Commission Joint Research Centre in Italy analysed satellite data from the Global Forest Change database containing measurements of the amount of forest cover and area of trees cut down between 2004 and 2018 across 26 countries in the European Union.
Between 2016 and 2018, the harvested forest area across Europe was almost 50 per cent higher and the estimated annual levels of harvested biomass were almost 70 per cent higher compared to the preceding five years. The findings indicate that more trees were harvested in a relatively short period of time, accounting for natural cycles and the impact of events, such as forest fires, which cause less than 10 per cent variation each year.
While the study itself cannot prove the causal links, several possible drivers have been proposed. The recent surge in harvesting in Europe is likely due – at least, in part – to increased demand for wood burned as fuel or for timber-based products. However, more research is still needed to ensure Europe’s forests are indeed being sustainably managed and that there are no underlying problems in the EU’s conservation strategies.
Increases in harvesting were most striking in Scandanavian and Eastern European countries. More than half of the total observed increase in harvested forest area was in Sweden (22 per cent) and Finland (29 per cent). Both countries are highly dependent on forestry-related industries. Latvia and Estonia also showed marked increases, and similar trends were found in France and Portugal, albeit less pronounced.
Less forest cover means less CO2 captured from the atmosphere and stored in trees, which will reduce the ability of European forests to act as a carbon sink. Moreover, if some of the harvested trees are burned or allowed to rot, they will release more stored carbon back into the atmosphere.
Lead author Guido Ceccherini told the Guardian: “The forests continue to remain a carbon sink, but less than before. Even if part of the harvested biomass carbon is used in long-lasting wood products, possibly replacing more energy-intensive materials such as steel or cement, most of it will return to the atmosphere as CO2 in a short period of time, [from] months to a few years.”
Interestingly, the total area of European forest is, in fact, expanding. Overall forest cover across the continent has increased in the past five years. But is this parallel growth enough to offset the losses?
The researchers note that new growth is not as efficient in taking up CO2 as older trees. Furthermore, depending on the type of forest, it could take decades for carbon stocks in harvested areas to return to prior levels. Ceccherini explained: “Until the carbon stock in harvested areas returns to previous levels, which takes several decades, depending on the type of forest, an increase in harvest is therefore equivalent to an increase in carbon dioxide emissions to the atmosphere.”
In other words, the dramatic shift in harvested forest area might mean even more emissions reductions are necessary – forests currently offset around 10 per cent of the EU’s greenhouse gas emissions. Therefore, the authors urge the EU to consider increased harvesting in designing future climate mitigation goals.
(1) Ceccherini, G. et al. Abrupt increase in harvested forest area over Europe after 2015. Nature (2020). DOI: 10.1038/s41586-020-2438-y