Influence of CO2 emission rates on the stability of the thermohaline circulation

Thomas F. Stocker () and Andreas Schmittner
Additional contact information
Thomas F. Stocker: Climate and Environmental Physics, Physics Institute, University of Bern
Andreas Schmittner: Climate and Environmental Physics, Physics Institute, University of Bern

Nature, 1997, vol. 388, issue 6645, 862-865

Abstract: Abstract Present estimates of the future oceanic uptake of anthropogenic CO2 and calculations of CO2-emission scenarios1 are based on the assumption that the natural carbon cycle is in steady state. But it iswell known from palaeoclimate records2,3,4,5 and modelling studies6,7,8,9 that the climate system has more than one equilibrium state, and that perturbations can trigger transitions between them. Anticipated future changes in today's climate system due to human activities have the potential to weaken the thermohaline circulation of the North Atlantic Ocean10,11,12, which would greatly modify estimates of future oceanic CO2 uptake13. Here we use a simple coupled atmosphere–ocean climate model to show that the Atlantic thermohaline circulation is not only sensitive to the final atmospheric CO2 concentration attained, but also depends on the rate of change of the CO2 concentration in the atmosphere. A modelled increase to 750 parts per million by volume (p.p.m.v.) CO2 within 100 years (corresponding approximately to a continuation of today's growth rate) leads to a permanent shut-down of the thermohaline circulation. If the final atmospheric concentration of 750 p.p.m.v. CO2 is attained more slowly, the thermohaline circulation simply slows down. The reason for this rate-sensitive response of the climate system lies with the transfer of buoyancy in the form of heat and fresh water from the uppermost layers of the ocean into the deep waters below. This sensitivity of the simulated thermohaline circulation to the rate ofchange of atmospheric CO2 concentration has potentially important implications for the choice of future CO2-emission scenarios1.

Date: 1997
References: Add references at CitEc
Citations: View citations in EconPapers (22)

Downloads: (external link)
https://www.nature.com/articles/42224 Abstract (text/html)
Access to the full text of the articles in this series is restricted.

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:nat:nature:v:388:y:1997:i:6645:d:10.1038_42224

Ordering information: This journal article can be ordered from
https://www.nature.com/

DOI: 10.1038/42224

Access Statistics for this article

Nature is currently edited by Magdalena Skipper

More articles in Nature from Nature
Bibliographic data for series maintained by Sonal Shukla () and Springer Nature Abstracting and Indexing ().