In order to limit the amount of global warming by 2020 to only 1.5 degrees Celsius, countries under the Paris Agreement may have to strengthen their carbon reduction pledges, a new study suggests. Researchers assessed remaining carbon budgets that are compatible with limiting warming to 1.5 °C by using a simple carbon-climate model, key properties of the climate system and the present-day climate state. Their estimations of remaining carbon budget—the amount of carbon dioxide emissions that can be released into the atmosphere while still limiting the human-induced warming to 1.5°C—suggest that Paris Agreement goals can be achieved as long as countries commit to reviewing and reducing carbon emission targets annually, as well as mitigating greenhouse gases other than carbon dioxide.


Gunnar Myhre, Cathrine Lund Myhre, Piers M. Forster & Keith P. Shine

Canadian author:

Damon Matthews, Climate Science, Mitigation and Impact Studies Lab, Concordia University, Montreal, QC, Email:

Corresponding author:

Richard Millar, University of Exeter and University of Oxford, UK, Email:

Original paper published in Nature on September 18, 2017.