Student or educator? Sign up with your school email and get 6 months of Pro free.
Cited by 958

The DOI matches its Crossref record; 8 of the 8 references it cites were found in a registry or an index.

Target Atmospheric CO: Where Should Humanity Aim?

Open access
Hansen, James, Sato, Makiko, Kharecha, Pushker, Beerling, David, Berner, Robert, Masson-Delmotte, Valerie, Pagani, Mark, Raymo, Maureen, Royer, Dana L., Zachos, James C.·2008·The Open Atmospheric Science Journal

Abstract

Paleoclimate data show that climate sensitivity is ~3°C for doubled CO 2, including only fast feedback processes. Equilibrium sensitivity, including slower surface albedo feedbacks, is ~6°C for doubled CO 2 for the range of climate states between glacial conditions and ice-free Antarctica. Decreasing CO was the main cause of a cooling trend that began 50 million years ago, the planet being nearly ice-free until CO fell to 450 ± 100 ppm; barring prompt policy changes, that critical level will be passed, in the opposite direction, within decades. If humanity wishes to preserve a planet similar to that on which civilization developed and to which life on Earth is adapted, paleoclimate evidence and ongoing climate change suggest that CO 2 will need to be reduced from its current 385 ppm to at most 350 ppm, but likely less than that. The largest uncertainty in the target arises from possible changes of non-CO 2 forcings. An initial 350 ppm CO 2 target may be achievable by phasing out coal use except where CO 2 is captured and adopting agricultural and forestry practices that sequester carbon. If the present overshoot of this target CO 2 is not brief, there is a possibility of seeding irreversible catastrophic effects.

Overview

The claims and statistics of this paper haven’t been checked yet.

Run the check — free, no account needed. It reads the open-access text and checks the sources it cites.

A few free checks a day · papers already verified open instantly · results are public

Integrity signals

Registry

Crossref · 10.2174/1874282300802010217

Cites

8 of 8 references verified0 citation errors · 0 not checkable

Statistics

Verification

Claims the paper makes

The claims and statistics of this paper haven’t been checked yet.

Run the check — free, no account needed. It reads the open-access text and checks the sources it cites.

A few free checks a day · papers already verified open instantly · results are public

Self-check

Percentages, sums and reported differences re-computed from the paper’s own numbers.

The self-check needs the paper’s full text.

Citations

Cites

Show all 8 references

Cited by

See all 958

Metadata

Authors
Hansen, J., Sato, M., Kharecha, P., Beerling, D., Berner, R., Masson-Delmotte, V., Pagani, M., Raymo, M., Royer, D. L., & Zachos, J. C.
Venue
The Open Atmospheric Science Journal
Published
2008-10-31
Volume
2
Issue
1
Pages
217-231
ISSN
1874-2823 (ISSN-L)
OpenAlex
W2150186950
Cited by
958
References
8
FWCI
78.15
Type
journal article
Language
en
Open access
hybrid

About these checks

Registry, retraction, Cites and statistics results are computed, not judged, with one exception: a printed reference that no index lists is read once by a model before it counts as a citation error. Claims are extracted by a model and kept only when their quote appears verbatim in the text; each cited source is then checked, with a model’s help, for whether it says what the claim relies on. Those verdicts can be wrong — read the claim’s quote and the cited source before relying on one.

Statistics and arithmetic are recomputed, not judged.

Confidence bands are shown only for fields calibrated on our annotated test set. None is calibrated yet, so no band is shown.

What counts as a claim ›How we measure confidence ›How we check this ›

Are you an author, or do you see a problem with this page? Request a review

How to cite

Cite CoChat for the checks on this page, and the paper for its own findings.

This page
CoChat. (2026). Citation check: Target Atmospheric CO: Where Should Humanity Aim? https://app.cochat.ai/papers/10.2174/1874282300802010217
The paper
Hansen, J., Sato, M., Kharecha, P., Beerling, D., Berner, R., Masson-Delmotte, V., Pagani, M., Raymo, M., Royer, D. L., & Zachos, J. C. (2008). Target Atmospheric CO: Where Should Humanity Aim? The Open Atmospheric Science Journal. https://doi.org/10.2174/1874282300802010217

Data sources

Bibliographic data: Semantic Scholar, OpenAlex, Crossref.

Contains information from the Semantic Scholar Academic Graph Datasets, made available under the ODC Attribution License (ODC-BY 1.0).

Semantic Scholar’s data is described in: Kinney, R., et al. (2023). The Semantic Scholar Open Data Platform. arXiv:2301.10140.