Ensemble reconstruction constraints on the global carbon cycle sensitivity to climate

Autoren

David C Frank
Jan Esper
Christoph C Raible
Ulf Büntgen
Valerie Trouet
Benjamin Stocker
Fortunat Joos

DOI

10.1038/nature08769

eISSN

1476-4687

ISSN

0028-0836

Ausgabe der Veröffentlichung

7280

Zeitschrift

Nature

Sprache

en

Online publication date

2010

Paginierung

527 - 530

Datum der Veröffentlichung

2010

Status

Published

Herausgeber

Springer Science and Business Media LLC

Herausgeber URL

http://dx.doi.org/10.1038/nature08769

Datum der Datenerfassung

2023

Titel

Ensemble reconstruction constraints on the global carbon cycle sensitivity to climate

Ausgabe der Zeitschrift

463

Datenquelle: Crossref

Abstract

The processes controlling the carbon flux and carbon storage of the atmosphere, ocean and terrestrial biosphere are temperature sensitive and are likely to provide a positive feedback leading to amplified anthropogenic warming. Owing to this feedback, at timescales ranging from interannual to the 20-100-kyr cycles of Earth's orbital variations, warming of the climate system causes a net release of CO(2) into the atmosphere; this in turn amplifies warming. But the magnitude of the climate sensitivity of the global carbon cycle (termed gamma), and thus of its positive feedback strength, is under debate, giving rise to large uncertainties in global warming projections. Here we quantify the median gamma as 7.7 p.p.m.v. CO(2) per degrees C warming, with a likely range of 1.7-21.4 p.p.m.v. CO(2) per degrees C. Sensitivity experiments exclude significant influence of pre-industrial land-use change on these estimates. Our results, based on the coupling of a probabilistic approach with an ensemble of proxy-based temperature reconstructions and pre-industrial CO(2) data from three ice cores, provide robust constraints for gamma on the policy-relevant multi-decadal to centennial timescales. By using an ensemble of >200,000 members, quantification of gamma is not only improved, but also likelihoods can be assigned, thereby providing a benchmark for future model simulations. Although uncertainties do not at present allow exclusion of gamma calculated from any of ten coupled carbon-climate models, we find that gamma is about twice as likely to fall in the lowermost than in the uppermost quartile of their range. Our results are incompatibly lower (P < 0.05) than recent pre-industrial empirical estimates of approximately 40 p.p.m.v. CO(2) per degrees C (refs 6, 7), and correspondingly suggest approximately 80% less potential amplification of ongoing global warming.

Addresses

Swiss Federal Research Institute WSL, Zürcherstrasse 111, CH-8903 Birmensdorf, Switzerland. david.frank@wsl.ch

Autoren

David C Frank
Jan Esper
Christoph C Raible
Ulf Büntgen
Valerie Trouet
Benjamin Stocker
Fortunat Joos

DOI

10.1038/nature08769

eISSN

1476-4687

Externe Identifier

PubMed Identifier: 20110999

Open access

false

ISSN

0028-0836

Ausgabe der Veröffentlichung

7280

Zeitschrift

Nature

Schlüsselwörter

Carbon Dioxide
Carbon
Temperature
Ice
Models, Theoretical
Time Factors
Climate Change

Sprache

eng

Medium

Print

Paginierung

527 - 530

Datum der Veröffentlichung

2010

Status

Published

Datum der Datenerfassung

2010

Titel

Ensemble reconstruction constraints on the global carbon cycle sensitivity to climate.

Sub types

Research Support, Non-U.S. Gov't
Journal Article

Ausgabe der Zeitschrift

463

Datenquelle: Europe PubMed Central

Abstract

The processes controlling the carbon flux and carbon storage of the atmosphere, ocean and terrestrial biosphere are temperature sensitive and are likely to provide a positive feedback leading to amplified anthropogenic warming. Owing to this feedback, at timescales ranging from interannual to the 20-100-kyr cycles of Earth's orbital variations, warming of the climate system causes a net release of CO(2) into the atmosphere; this in turn amplifies warming. But the magnitude of the climate sensitivity of the global carbon cycle (termed gamma), and thus of its positive feedback strength, is under debate, giving rise to large uncertainties in global warming projections. Here we quantify the median gamma as 7.7 p.p.m.v. CO(2) per degrees C warming, with a likely range of 1.7-21.4 p.p.m.v. CO(2) per degrees C. Sensitivity experiments exclude significant influence of pre-industrial land-use change on these estimates. Our results, based on the coupling of a probabilistic approach with an ensemble of proxy-based temperature reconstructions and pre-industrial CO(2) data from three ice cores, provide robust constraints for gamma on the policy-relevant multi-decadal to centennial timescales. By using an ensemble of >200,000 members, quantification of gamma is not only improved, but also likelihoods can be assigned, thereby providing a benchmark for future model simulations. Although uncertainties do not at present allow exclusion of gamma calculated from any of ten coupled carbon-climate models, we find that gamma is about twice as likely to fall in the lowermost than in the uppermost quartile of their range. Our results are incompatibly lower (P < 0.05) than recent pre-industrial empirical estimates of approximately 40 p.p.m.v. CO(2) per degrees C (refs 6, 7), and correspondingly suggest approximately 80% less potential amplification of ongoing global warming.

Date of acceptance

2009

Autoren

David C Frank
Jan Esper
Christoph C Raible
Ulf Büntgen
Valerie Trouet
Benjamin Stocker
Fortunat Joos

Autoren-URL

https://www.ncbi.nlm.nih.gov/pubmed/20110999

DOI

10.1038/nature08769

eISSN

1476-4687

Ausgabe der Veröffentlichung

7280

Zeitschrift

Nature

Schlüsselwörter

Carbon
Carbon Dioxide
Climate Change
Ice
Models, Theoretical
Temperature
Time Factors

Sprache

eng

Country

England

Paginierung

527 - 530

PII

nature08769

Datum der Veröffentlichung

2010

Status

Published

Datum, an dem der Datensatz öffentlich gemacht wurde

2010

Titel

Ensemble reconstruction constraints on the global carbon cycle sensitivity to climate.

Sub types

Journal Article
Research Support, Non-U.S. Gov't

Ausgabe der Zeitschrift

463

Datenquelle: PubMed

Ensemble reconstruction constraints on the global carbon cycle sensitivity to climate

Werkzeuge