Increasing impact of warm droughts on northern ecosystem productivity over recent decades

• Published in: Nature climate change Vol. 11; no. 9; pp. 772 - 779
• Main Authors: Gampe, David, Zscheischler, Jakob, Reichstein, Markus, O’Sullivan, Michael, Smith, William K., Sitch, Stephen, Buermann, Wolfgang
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 01-09-2021; Nature Publishing Group
• Subjects: 704/106/47; 704/106/694/2739; 704/47; Agricultural land; Carbon; Carbon sinks; Carbon uptake; Climate; Climate Change; Climate Change/Climate Change Impacts; Climatic extremes; Drought; Earth and Environmental Science; Ecosystems; Environment; Environmental Law/Policy/Ecojustice; Extreme weather; Food security; Grasslands; Growing season; Heat waves; Heatwaves; Primary production; Productivity; Uptake; Vulnerability
• ISSN: 1758-678X; 1758-6798
• DOI: 10.1038/s41558-021-01112-8

Climate extremes such as droughts and heatwaves have a large impact on terrestrial carbon uptake by reducing gross primary production (GPP). While the evidence for increasing frequency and intensity of climate extremes over the last decades is growing, potential systematic adverse shifts in GPP have not been assessed. Using observationally-constrained and process-based model data, we estimate that particularly northern midlatitude ecosystems experienced a +10.6% increase in negative GPP extremes in the period 2000–2016 compared to 1982–1998. We attribute this increase predominantly to a greater impact of warm droughts, in particular over northern temperate grasslands (+95.0% corresponding mean increase) and croplands (+84.0%), in and after the peak growing season. These results highlight the growing vulnerability of ecosystem productivity to warm droughts, implying increased adverse impacts of these climate extremes on terrestrial carbon sinks as well as a rising pressure on global food security.
The authors show increased negative extremes in gross primary productivity in northern midlatitude ecosystems, particularly over grasslands and croplands, attributed to impacts of warm droughts. This highlights the vulnerability of terrestrial carbon sinks and food security to increasing extreme events.