Story · Europe map · about 4 min
Forests felled, burned and replanted
Satellites have mapped tree loss at 30 m since 2001. This tour uses the year slider on the tree cover layer, which starts from the trees standing in 2000 and takes away whatever was lost, to tell logging from fire, and to see what the picture cannot show.
The northern forests in 2000
In 2000 the layer shows how much of each 450 m block was covered by trees, counting only cover of 30% canopy or more: the dark green of Sweden, Finland and the Baltic states is nearly unbroken forest. Each later year shows what remains once the satellites’ record of loss up to that year is taken away. Drag the slider to watch it thin.
A fifth of the north counts as lost
By 2024 the layer counts 21% of Sweden’s 2000 tree cover as lost, 22% of Finland’s, 24% of Estonia’s and 27% of Latvia’s. Most of this is forestry: these forests are clear-felled and replanted on a cycle. But the layer cannot add the young trees back, so a forest that is being renewed looks permanently thinner than it is.
Portugal, the year of the fires
Portugal has the largest share counted as lost of any country in this tour: 55% of its 2000 tree cover by 2024. In 2017 alone it lost 7.6%, its worst year, and the blocks around Pedrógão Grande fell from an average of 53% tree-covered in 2016 to 25% in 2017. Some of Portugal’s loss is fire and some is plantation forestry cut and regrown; the layer cannot tell which.
Euboea, August 2021
Greece’s worst year in the record is 2021, when it lost 1.3% of its 2000 tree cover; by 2024 the total is 8.2%. Look at northern Euboea: blocks of about 450 m that stood at 91% to 98% tree cover in 2020 read 0% to 3% in 2021, the fire of August 2021. A fire is the clearest signal the layer gives, because the trees do not come back within the series.
Loss is not deforestation
Norway lost 8.5% and France 9.2% of their 2000 tree cover, less than half of Latvia’s share, yet nobody would call Latvia the more deforested country. Loss is not deforestation: the satellites record a stand being removed, and cannot say whether it grows back or becomes a field. Use the slider to find the sudden years, which are fires and storms, and read the slow thinning as forestry.
For classrooms and curious minds
Questions to talk about, alone or in a group.
- Sweden’s tree cover counts 21% as lost, yet its forests are not disappearing. What does the layer measure, and what can it not see?
- How can you tell a fire from forestry in the slider, and what else would you check before calling a loss deforestation?
Try it on the map: Switch on the tree cover layer and drag from 2016 to 2017 over central Portugal, then from 2020 to 2021 over northern Euboea. Then drag slowly over Sweden. What is different about the way the loss arrives?
The figures above are calculated from the datasets listed on Data & sources and are approximate: many map layers are modelled or interpolated. Read each layer’s caveats on the map.