How will rising CO2 affect vegetation in the Sahel? Sebastian Bathiany, Martin Claussen, Victor Brovkin Max Planck Institute for Meteorology
Petit-Maire, 1990: Sahel
Plants need food and water CO2 (physiological)
Plants need food and water CO2 (physiological) Climate (most important: rainfall)
Model description MPI-ESM-LR HadGEM2-ES MIROC-ESM
21st century Change in vegetation cover fraction (abs. %)
21st century Change in vegetation cover fraction (abs. %)
21st century 22-23rd century Change in vegetation cover fraction (abs. %)
Separation of effects Radphys Rad Phys Experiment Plants see climate change Plants see CO2 change Radphys Rad Phys
Separation of effects Radphys Rad Phys Change in vegetation cover fraction (abs. %)
Separation of effects Radphys Rad Phys Change in vegetation cover fraction (abs. %)
Separation of effects Radphys Rad Phys Change in vegetation cover fraction (abs. %)
Plants need food and water CO2 (physiological) Climate (most important: precipitation)
Darker surface warms…
but transpiration cools…
vegFrac [abs %]
vegFrac [abs %]
Summary Vegetation cover change in the Sahel depends on the time horizon. Reasons for vegetation cover change are different in each model. Uncertain effects oppose each other. In the Sahel, vegetation expansion could cool. High resolution is necessary.