Predicted Chance That Global Warming Will Temporarily Exceed 1.5 °C

TitlePredicted Chance That Global Warming Will Temporarily Exceed 1.5 °C
Publication TypeJournal Article
Year of Publication2019
JournalGeophysical Research Letters
Volume45
Number21
Pages11,895-11,903
Date Published02/2019
Abstract

The Paris Agreement calls for efforts to limit anthropogenic global warming to less than 1.5 °C above preindustrial levels. However, natural internal variability may exacerbate anthropogenic warming to produce temporary excursions above 1.5 °C. Such excursions would not necessarily exceed the Paris Agreement, but would provide a warning that the threshold is being approached. Here we develop a new capability to predict the probability that global temperature will exceed 1.5 °C above preindustrial levels in the coming 5 years. For the period 2017 to 2021 we predict a 38% and 10% chance, respectively, of monthly or yearly temperatures exceeding 1.5 °C, with virtually no chance of the 5‐year mean being above the threshold. Our forecasts will be updated annually to provide policy makers with advanced warning of the evolving probability and duration of future warming events.

URLhttp://dx.doi.org/10.1029/2018gl079362
DOI10.1029/2018gl079362
Journal: Geophysical Research Letters
Number: 21
Volume: 45

The Paris Agreement calls for efforts to limit anthropogenic global warming to less than 1.5 °C above preindustrial levels. However, natural internal variability may exacerbate anthropogenic warming to produce temporary excursions above 1.5 °C. Such excursions would not necessarily exceed the Paris Agreement, but would provide a warning that the threshold is being approached. Here we develop a new capability to predict the probability that global temperature will exceed 1.5 °C above preindustrial levels in the coming 5 years. For the period 2017 to 2021 we predict a 38% and 10% chance, respectively, of monthly or yearly temperatures exceeding 1.5 °C, with virtually no chance of the 5‐year mean being above the threshold. Our forecasts will be updated annually to provide policy makers with advanced warning of the evolving probability and duration of future warming events.

DOI: 10.1029/2018gl079362
Year of Publication: 2019
Citation:
Smith, D, A Scaife, E Hawkins, R Bilbao, G Boer, M Caian, L Caron, G Danabasoglu, T Delworth, F Doblas-Reyes, R Doescher, N Dunstone, R Eade, L Hermanson, M Ishii, V Kharin, M Kimoto, T Koenigk, Y Kushnir, D Matei, G Meehl, M Menegoz, W Merryfield, T Mochizuki, W Müller, H Pohlmann, S Power, M Rixen, R Sospedra-Alfonso, M Tuma, K Wyser, X Yang, and S Yeager.  2019.  "Predicted Chance That Global Warming Will Temporarily Exceed 1.5 °C."  Geophysical Research Letters 45(21): 11895-11903, doi:10.1029/2018gl079362.