EGU21-13243
https://doi.org/10.5194/egusphere-egu21-13243
EGU General Assembly 2021
© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.

No “Abrupt increase in harvested forest area over Europe after 2015” – How the misuse of a satellite-based map led to completely wrong conclusions

Johannes Breidenbach1, David Ellison2,3,4, Hans Petersson2, Kari Korhonen5, Helena Henttonen5, Jörgen Wallerman2, Jonas Fridman2, Terje Gobakken6, Rasmus Astrup1, and Erik Næsset6
Johannes Breidenbach et al.
  • 1Division of Forestry and Forest Resources, NIBIO (Norwegian Institute of Bioeconomy Research), Ås, Norway
  • 2Department of Forest Resource Management, Swedish University of Agricultural Sciences, Umeå, Sweden
  • 3Land Systems and Sustainable Land Management Unit, Institute of Geography, University of Bern, Switzerland
  • 4Ellison Consulting, Baar, Switzerland
  • 5Natural Resources Institute Finland (Luke), Helsinki, Finland
  • 6Faculty of Environmental Sciences and Natural Resource Management, Norwegian University of Life Sciences, Ås, Norway

In a recent Nature article, the satellite-based Global Forest Change (GFC) map was used to estimate the yearly harvest area in each of the EU26-states over the period 2004 to 2018 (Ceccherini et al. 2020). Finland and Sweden were identified as the countries with the largest harvest increases and the biggest effect on the EU’s climate policy strategy. Here, we employ more than 45,000 field observations from the Finnish and Swedish national forest inventories as reference observations to analyze the accuracy of GFC data. We find that harvested area increases only marginally, if at all, after 2015. What did increase abruptly after 2015, however, was GFC’s sensitivity to detect harvested areas and thinnings.

The results of the Nature article are therefore a consequence of an inconsistent time series in GFC due to a change in the mapping algorithm or the sensor system and are thus both incorrect and misleading. The article is thus a good example for how wrong results based on satellite data can be, if no adequate estimators utilizing reference data are used.

 

References

Ceccherini, G. et al. Abrupt increase in harvested forest area over Europe after 2015. Nature 583, 72-77 (2020).

How to cite: Breidenbach, J., Ellison, D., Petersson, H., Korhonen, K., Henttonen, H., Wallerman, J., Fridman, J., Gobakken, T., Astrup, R., and Næsset, E.: No “Abrupt increase in harvested forest area over Europe after 2015” – How the misuse of a satellite-based map led to completely wrong conclusions, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-13243, https://doi.org/10.5194/egusphere-egu21-13243, 2021.

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