CO2-driven Shift of a Tipping Point in Net Ecosystem Production

The possibility that terrestrial ecosystems as a whole may shift from a carbon sink to a carbon source is a major concern in climate change science. According to numerical experiments on Earth System Models, this is unlikely to happen in the near future. However, the transformation from a carbon sink to a carbon source seems much more likely in the case of some regions. Analyzing an ecosystem carbon cycle with a model of reduced complexity, we find that low sensitivity of regional actual evapotranspiration to global warming might be a distinctive feature of the regions which are relatively safe for allocation of the land-based carbon dioxide removal projects.