Recent Warming Has Resulted in Smaller Gains in net Carbon Uptake in Northern High Latitudes
Carbon balance of terrestrial ecosystems in the northern high latitudes is sensitive to climate change. Here we assess long-term changes in the sensitivity of the carbon balance to environmental changes, and using atmospheric observations show a declining sensitivity over time.
The results suggest that the current NHL carbon sink may become unsustainable as temperatures warm further. Current carbon cycle models do not represent the decrease temperature sensitivity.
We used atmospheric CO2 observations to find that the sensitivity of carbon drawdown to inter-annual temperature changes has trended toward less carbon uptake for a given amount of warming from 1974 to 2014. These results suggest that relatively warm springs now result in less carbon uptake. Similarly, relatively warm summers now result in greater carbon release.