Enhanced seasonal CO 2 exchange caused by amplified plant productivity in northern ecosystems

Abstract

Warming making bigger CO 2 swings The combined effects of climate change and vegetation dynamics at high northern latitudes have amplified the seasonal variation of atmospheric CO 2 concentrations over the past half century. Forkel et al. combined observations and models to show that climate warming has caused the photosynthetic uptake of carbon to increase faster than its respiratory release from the terrestrial biosphere. This has increased the difference from summer to winter, as well as the latitudinal gradient. Because of the physiological limitations to carbon uptake by terrestrial vegetation, this negative feedback to warming in the boreal north and Arctic cannot continue indefinitely. Science , this issue p. 696