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Delays in US mitigation could rule out Paris targets

Nature Climate Change volume 7, pages 92–94 (2017)Cite this article

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Political upsets could stall coordinated international mitigation action, but emissions and investments over the next few years will have long-term consequences. Any delays to mitigation or cuts to renewable energy research by the US will likely render the 2 °C target unachievable if a global precedent is set.

On 4 November 2016 the Paris Agreement entered into force: the first global plan to limit climate change, a milestone after more than twenty years of difficult international negotiations. Days later the Republican candidate Donald Trump, who has stated that he would pull out of the Paris Agreement, was elected as the next US president. Much has been speculated about the future of the Paris Agreement since then, but quantitative analyses of the consequences of plausible scenarios in light of the election are worth considering. A naive assessment of a brief delay in US climate mitigation could conclude that the world would just reach its climate targets a few years later. This idea that 'if we don't fix it today, we'll fix it next year' works for many problems, like rebuilding infrastructure, but not for climate change: CO2 continues to accumulate, and warming is essentially proportional to the total accumulated emissions over time, rather than those in a given year (see ref. 1 for a review). Achieving a temperature target of below 2 °C or 1.5 °C as agreed in Paris therefore implies a fixed total amount of CO2 that can be emitted, often called the carbon budget. The sum of all future emissions depends on three factors: the timescale of carbon policy implementation, the aggressiveness of emissions reduction, and whether large scale removal of CO2 from the atmosphere can be deployed to compensate for emissions (or to pull us back if the budget is overspent). As we argue here, decisions by the new US administration may affect all of these.

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Figure 1: Delayed-action emissions pathways and their consequences for global temperatures.

Change history

  • 04 January 2017

    In a previous online version of the Commentary 'Delays in US mitigation could rule out Paris targets' the surname of the first author in ref. 1 was misspelt. This has been corrected in all versions of the Commentary.

References

  1. 1

    Knutti, R. & Rogelj, J. Climatic Change 133, 361–373 (2015).

    CAS  Article  Google Scholar 

  2. 2

    The Emissions Gap Report 2016 (UNEP, 2016).

  3. 3

    Jacques, C. A Trump Presidency Could Mean 3.4 Billion Tons More US Carbon Emissions than a Clinton One (luxresearch, 2016).

  4. 4

    Fuss, S. et al. Nat. Clim. Change 4, 850–853 (2014).

    CAS  Article  Google Scholar 

  5. 5

    Sanderson, B. M., O'Neill, B. C. & Tebaldi, C. Geophys. Res. Lett. 43, GL069563 (2016).

    Article  Google Scholar 

  6. 6

    Shared Socioeconomic Pathways Version 1.1 (Science for Global Insight, accessed 15 November 2016); http://go.nature.com/2iepr2x

  7. 7

    Rogelj, J. et al. Nat. Clim. Change 6, 245–252 (2016).

    Article  Google Scholar 

  8. 8

    Solomon, S., Plattner, G.-K., Knutti, R. & Friedlingstein, P. Proc. Natl Acad. Sci. USA 106, 1704–1709 (2009).

    CAS  Article  Google Scholar 

  9. 9

    Matthews, H. D. & Solomon, S. Science 340, 438–439 (2013).

    CAS  Article  Google Scholar 

  10. 10

    Rogelj, J., McCollum, D. L., Reisinger, A., Meinshausen, M. & Riahi, K. Nature 493, 79–83 (2013).

    Article  Google Scholar 

Download references

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Affiliations

  1. The National Center for Atmospheric Research, 1850 Table Mesa Drive, Boulder, 80305, Colorado, USA

    Benjamin M. Sanderson & Reto Knutti

  2. Institute for Atmospheric and Climate Science, ETH Zurich, Zurich, CH-8092, Switzerland

    Reto Knutti

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  1. Benjamin M. Sanderson
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  2. Reto Knutti
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Correspondence to Benjamin M. Sanderson.

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Sanderson, B., Knutti, R. Delays in US mitigation could rule out Paris targets. Nature Clim Change 7, 92–94 (2017). https://doi.org/10.1038/nclimate3193

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