Current Climate Change Reports

, Volume 3, Issue 1, pp 69–77

Estimating Carbon Budgets for Ambitious Climate Targets

  • H. Damon Matthews
  • Jean-Sébastien Landry
  • Antti-Ilari Partanen
  • Myles Allen
  • Michael Eby
  • Piers M. Forster
  • Pierre Friedlingstein
  • Kirsten Zickfeld
Carbon Cycle and Climate (K Zickfeld, Section Editor)

DOI: 10.1007/s40641-017-0055-0

Cite this article as:
Matthews, H.D., Landry, JS., Partanen, AI. et al. Curr Clim Change Rep (2017) 3: 69. doi:10.1007/s40641-017-0055-0
Part of the following topical collections:
  1. Topical Collection on Carbon Cycle and Climate

Abstract

Carbon budgets, which define the total allowable CO2 emissions associated with a given global climate target, are a useful way of framing the climate mitigation challenge. In this paper, we review the geophysical basis for the idea of a carbon budget, showing how this concept emerges from a linear climate response to cumulative CO2 emissions. We then discuss the difference between a “CO2-only carbon budget” associated with a given level of CO2-induced warming and an “effective carbon budget” associated with a given level of warming caused by all human emissions. We present estimates for the CO2-only and effective carbon budgets for 1.5 and 2 °C, based on both model simulations and updated observational data. Finally, we discuss the key contributors to uncertainty in carbon budget estimates and suggest some implications of this uncertainty for decision-making. Based on the analysis presented here, we argue that while the CO2-only carbon budget is a robust upper bound on allowable emissions for a given climate target, the size of the effective carbon budget is dependent on the how quickly we are able to mitigate non-CO2 greenhouse gas and aerosol emissions. This suggests that climate mitigation efforts could benefit from being responsive to a changing effective carbon budget over time, as well as to potential new information that could narrow uncertainty associated with the climate response to CO2 emissions.

Keywords

Carbon Budgets Cumulative CO2 Emissions Climate Targets Climate Mitigation 

Copyright information

© Springer International Publishing AG 2017

Authors and Affiliations

  • H. Damon Matthews
    • 1
  • Jean-Sébastien Landry
    • 2
  • Antti-Ilari Partanen
    • 1
    • 3
  • Myles Allen
    • 4
  • Michael Eby
    • 5
  • Piers M. Forster
    • 6
  • Pierre Friedlingstein
    • 7
  • Kirsten Zickfeld
    • 5
  1. 1.Concordia UniversityMontrealCanada
  2. 2.Université de SherbrookeSherbrookeCanada
  3. 3.Finnish Meteorological InstituteHelsinkiFinland
  4. 4.Oxford UniversityOxfordUK
  5. 5.Simon Fraser UniversityVancouverCanada
  6. 6.Leeds UniversityLeedsUK
  7. 7.Exeter UniversityExeterUK