The quantity 350 ppm has become an iconic number for the safe upper level of concentration of CO₂ in the atmosphere, promoted widely by environmentalists, scientists, and policymakers. But the simplistic focus on a single number, no matter how laudable for ease of communication, clouds the reality of the scientific complexity and the enormous political challenge of re-engineering the world’s energy supply.

Baker, D.J. 2011. Review of The Science and Politics of Global Climate Change: A Guide to the Debate (second edition), by A. Dessler and E.A. Parson. Oceanography 24(1):178–179, https://doi.org/10.5670/oceanog.2011.17.

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