Recognising the importance of unmanaged forests to mitigate climate change

The carbon stock in Europe’s forests is decreasing and the importance of protecting ‘unmanaged’ forests must be recognised in reversing this process. Scientific evidence suggests that ‘unmanaged’ forests have higher total biomass carbon stock than secondary forests being actively managed for commodity production or recently abandoned.

Following an opinion piece by by Schulze et al. (2020) we challenged a number of points raised that are either inaccurate or questionable.

Schulze et al.'s opinion compares differences in carbon storage between ‘unmanaged’ and ‘managed’ European forests, and they state, ‘(f)or unmanaged forests, the contribution to climate change mitigation through storage is very small or close to nil’. However, no evidence is cited to support this contention, which is inconsistent with several published empirical studies and theoretical analyses (Erb et al., 2017; Houghton & Nassikas, 2018; Lutz et al., 2018). In order to support effective climate policy, we are responding to identify some of the errors of omission in the Opinion.

Based on UNFCCC accounting rules, climate mitigation depends on the relative carbon stocks in the biosphere and atmosphere, not on sequestration rates as annual flows. In order to minimize the amount of carbon in the atmosphere, the cumulative carbon in trees and soils must be maximized (Mackey et al., 2020). The maximum carbon stored in forests occurs when forests are allowed to continue growing, a management practice called ‘proforestation’ (Moomaw et al., 2019). As the harvest rotation period is shortened, less carbon is stored in trees averaged over the harvest period intervals, leaving more in the atmosphere (Sterman, Siegel, & Rooney-Varga, 2018). Each harvest also releases additional biogenic and fossil fuel carbon emissions from the harvest process (Harris et al., 2016).


Article authors

Zoltan Kun

Zoltán Kun

Zoltán has expertise in forest management, protected area design and climate change mitigation in the temperate and boreal zone with particular attention to Europe.
Dominick Dellasala

Dominick DellaSalla

Dominick is Chief Scientist at Wild Heritage, and former President of the Society for Conservation Biology, North America Section and internationally renowned author of over 200 science papers on forest and fire ecology, conservation biology, endangered species management, and landscape ecology. .
Heather Keith

Heather Keith

Heather is a Senior Research Fellow at Griffith University. Her research is aimed at understanding the functioning of terrestrial ecosystems, particularly forests, to improve their management for conservation and climate change mitigation.
Cyril Kormos

Cyril Kormos

Cyril is Founder and Executive Director of Wild Heritage, a project of Earth Island Institute. He also serves as IUCN-WCPA Vice-Chair for World Heritage, is a member of IUCN’s World Heritage Panel and chairs the IUCN-WCPA World Heritage Network.
Bernard Mercer

Bernard Mercer

Bernard is an independent adviser to funders, NGOs and other organisations on environment issues, principally forests and other terrestrial ecosystems and their role within the climate challenge.

Additional authors

William R. Moomaw and Michal Wiezik


Kun Z., DellaSala D., Keith H., Kormos C., Mercer B., Moomaw W.R., Wiezik M., (2020), Recognizing the importance of unmanaged forests to mitigate climate change, GCB Bioenergy,