Title: Assessing terrestrial biogeochemical feedbacks in a strategically geoengineered climate

Abstract

Geoengineering by injecting sulfur dioxide (SO₂) into the lower stratosphere has been suggested to reduce anthropogenically induced warming. While impacts of such geoengineering on climate have been investigated in recent decades, few modeling studies have considered biogeochemical feedbacks resulting from such intervention. This study comprehensively characterizes responses and feedbacks of terrestrial ecosystems, from an ensemble of coupled high-resolution Earth system model climate change simulations, under the highest standard greenhouse gas scenario with an extreme geoengineering mitigation strategy. Under this strategy, temperature increases beyond 2020 levels due to elevated anthropogenic carbon dioxide (CO₂) were completely offset by the SO₂ injection. Carbon cycle feedbacks can alter the trajectory of atmospheric CO₂ levels by storing or releasing additional carbon on land and in the ocean, thus moderating or amplifying climate change. We assess terrestrial biogeochemical feedbacks to climate in response to geoengineering, using model output from the Stratospheric Aerosol Geoengineering Large Ensemble (GLENS) project. Results indicate terrestrial ecosystems become a stronger carbon sink globally because of lower ecosystem respiration and diminished disturbance effects under geoengineering. An additional 79 Pg C would be stored on land by the end of the twenty-first century, yielding as much as a 4% reduction in atmospheric CO₂ molemore » fraction without marine biogeochemical feedbacks, compared to the high greenhouse gas scenario without geoengineering.« less

Authors:

Yang, Cheng-En ;

• Search DOE PAGES for author "Yang, Cheng-En"
• Search DOE PAGES for ORCID "0000-0002-4069-4997"

Hoffman, Forrest M. ;

• Search DOE PAGES for author "Hoffman, Forrest M."
• Search DOE PAGES for ORCID "0000-0001-5802-4134"

Ricciuto, Daniel M. ;

• Search DOE PAGES for author "Ricciuto, Daniel M."
• Search DOE PAGES for ORCID "0000-0002-3668-3021"

Tilmes, Simone ;

• Search DOE PAGES for author "Tilmes, Simone"
• Search DOE PAGES for ORCID "0000-0002-6557-3569"

Xia, Lili ;

• Search DOE PAGES for author "Xia, Lili"
• Search DOE PAGES for ORCID "0000-0001-7821-9756"

MacMartin, Douglas G. ;

• Search DOE PAGES for author "MacMartin, Douglas G."
• Search DOE PAGES for ORCID "0000-0003-1987-9417"

Kravitz, Ben ;

• Search DOE PAGES for author "Kravitz, Ben"
• Search DOE PAGES for ORCID "0000-0001-6318-1150"

Richter, Jadwiga H. ;

• Search DOE PAGES for author "Richter, Jadwiga H."
• Search DOE PAGES for ORCID "0000-0001-7048-0781"

Mills, Michael ;

• Search DOE PAGES for author "Mills, Michael"
• Search DOE PAGES for ORCID "0000-0002-8054-1346"

Fu, Joshua S.

• Search DOE PAGES for author "Fu, Joshua S."
• Search DOE PAGES for ORCID "0000-0001-5464-9225"

Publication Date:

Wed Sep 30 00:00:00 EDT 2020

Research Org.:

Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

Sponsoring Org.:

USDOE Office of Science (SC), Biological and Environmental Research (BER); National Science Foundation (NSF)

OSTI Identifier:

1668885

Alternate Identifier(s):

OSTI ID: 1668886; OSTI ID: 1687359; OSTI ID: 1819624

Report Number(s):

PNNL-SA-152535
Journal ID: ISSN 1748-9326

Grant/Contract Number:  

RUBISCO SFA; TES SFA; AC05-00OR22725; AC05-76RL01830; CBET-1931641; AGS-1617844; 1852977

Resource Type:

Published Article

Journal Name:

Environmental Research Letters

Additional Journal Information:

Journal Name: Environmental Research Letters Journal Volume: 15 Journal Issue: 10; Journal ID: ISSN 1748-9326

Publisher:

IOP Publishing

Country of Publication:

United Kingdom

Language:

English

Subject:

54 ENVIRONMENTAL SCIENCES; geoengineering; carbon cycle; terrestrial biogeochemical feedbacks