Most plausible 2005-2040 emissions scenarios project less than 2.5 degrees C of warming by 2100 Journal Article uri icon



  • Emissions scenarios used by the Intergovernmental Panel on Climate Change (IPCC) are central to climate change research and policy. Here, we identify subsets of scenarios of the IPCC 5th (AR5) and forthcoming 6th (AR6) Assessment Reports that project 2005-2040 fossil-fuel CO2 emissions growth rates most consistently with observations from 2005-2020 and International Energy Agency (IEA) projections to 2040—71% of these scenarios project between 2 degrees C and 3 degrees C of warming by 2100, with a median of 2.2 degrees C. Though these IPCC scenarios do not represent all possible trajectories of future emissions and warming, and they assume continued mitigation progress, they do suggest the world is presently on a lower emissions trajectory than is often assumed. However, the scenarios also indicate that the world is still off track from limiting 21st-century warming to 1.5 degrees C.

publication date

  • March 23, 2021

has restriction

  • green

Date in CU Experts

  • March 24, 2021 11:42 AM

Full Author List

  • Pielke R; Burgess MG; Ritchie J

author count

  • 3

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