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Fifth National Climate Assessment - Read the Report

Investigating how ecosystems respond to climate warming


Scientists used SPRUCE (Spruce and Peatland Responses Under Changing Environments) experimental enclosures to record net carbon loss from warmed plots in the peatlands of Minnesota. Credit: Misha Krassovski, Oak Ridge National Laboratory/DOE.

Experimental warming of a peatland ecosystem showed a rapid shift towards net carbon loss to the atmosphere.

Peatlands cover only about 3 percent of Earth’s land surface but store around 30 percent of global soil carbon. As the climate warms, these carbon stocks are vulnerable to release into the atmosphere as the greenhouse gases carbon dioxide and methane, contributing to a cycle of further warming and carbon release. The SPRUCE (Spruce and Peatland Responses Under Changing Environments) experiment, a DOE and USDA Forest Service initiative, is a 10-year study involving warming of an intact Minnesota black spruce peatland ecosystem that aims to improve understanding of carbon cycle dynamics in these landscapes under future climate scenarios.

Results emerging from SPRUCE show that experimental warming causes peatlands to shift from net carbon accumulation to carbon sources faster than anticipated.1 This finding suggests that increased rates of global warming will have a significant impact on naturally stored carbon, with important feedbacks to the atmosphere that can drive further warming.


1 Hanson, Paul J.; Griffiths, Natalie A.; Iversen, Colleen M.; Norby, Richard J.; Sebestyen, Stephen D.; Phillips, Jana R.; Chanton, Jeffrey P.; Kolka, Randall K.; Malhotra, Avni; Oleheiser, Keith C.; Warren, Jeffrey M.; Shi, Xiaoying; Yang, Xiaojuan; Mao, Jiafu; Ricciuto, Daniel M. 2020. Rapid Net Carbon Loss From a Whole‐Ecosystem Warmed Peatland. AGU Advances. 1(3): e2020AV000163. ​​​18 p. https://doi.org/10.1029/2020av000163.