Legacy effects from historical environmental changes dominate future

Legacy effects from historical environmental changes dominate future terrestrial carbon uptake Andreas Krause 1, Almut Arneth 2, Anja Rammig 1 1 Technical University of Munich, TUM School of Life Sciences Weihenstephan, 85354 Freising, Germany 2 Institute of Meteorology and Climate Research, Atmospheric Environmental Research, Karlsruhe Institute of Technology, 82467 Garmisch-Partenkirchen, Germany Climate change • Ecosystem carbon storage depends on environmental conditions • However, ecosystems adapt only slowly to environmental changes carbon Land-use change CO 2 fertilization Wood harvest Nitrogen deposition and fertilization How important are legacy effects from historical environmental changes for future terrestrial carbon cycling?

The ecosystem model LPJ-GUESS Environmental drivers • LPJ-GUESS simulates ecosystem carbon storage in response to changing environmental conditions • Simulation period 1901 -2099 (SSP 5 -85 scenario for the future) • 0. 5° spatial resolution • 21 sensitivity experiments in which environmental drivers were fixed constant for specific time periods (1901 -2015 or 2015 -2099) • This allows for quantifying the effects of historical vs. future environmental changes on future terrestrial carbon cycling • Isolating the contributions of individual drivers is also possible

Results +126 Gt C +16 Gt C For individual contributions of specific environmental drivers (e. g. climate change) to these effects see Krause et al. (submitted) • Legacy effects from historical environmental changes will dominate terrestrial carbon cycling at least for the next three decades • Even by the end of the century, legacy effects are still much larger than effects from future environmental changes

Take-home message Legacy effects persist for many decades after environmental changes occurred and need to be considered when interpreting changes in terrestrial carbon stocks and estimating carbon uptake potentials! Questions and feedback in the live chat or to andy. krause@tum. de Group homepage: https: //www. lsai. wzw. tum. de/en/home/ Twitter: @LSAI_TUM