UCL Institute for Sustainable Resources


Limiting global warming to 1.5 °C may still be possible, according to new study

20 September 2017

A new study, co-authored by UCL ISR's Prof Michael Grubb, suggests that the 1.5°C Paris climate target is still possible, if emission reductions begin immediately


A new study, co-authored by Prof Michael Grubb from the UCL Institute for Sustainable Resources, investigated the geophysical likelihood of limiting global warming to "well below 2°C above pre-industrial levels and pursuing efforts to limit the temperature increase to 1.5°C." 

Published on 18 September in the journal Nature Geoscience, the study has been widely covered in the press with articles in BBC News, The Guardian, and the Times, amongst others.

The paper concludes that the goal of the Paris Agreement on Climate Change, limiting the increase in global average temperatures above pre-industrial levels to 1.5°C, is not yet geophysically impossible, however it will likely require more ambitious emission reductions than those pledged so far.

The study used three approaches to evaluate the outstanding 'carbon budget' (the total amount of CO2 emissions compatible with a given global average warming) for 1.5°C: re-assessing the evidence provided by complex Earth System Models, new experiments with an intermediate-complexity model, and evaluating the implications of current ranges of uncertainty in climate system properties using a simple model. In all cases the level of emissions and warming to date were taken into account.

Co-author Professor Michael Grubb, says: “This paper shows that the Paris goals are within reach, but clarifies what the commitment to 'pursue efforts to limit the temperature increase to 1.5°C' really implies.

'Starting with the global review due next year, countries have to get out of coal and strengthen their existing targets so as to keep open the window to the Paris goals. The sooner global emissions start to fall, the lower the risk not only of major climatic disruption, but also of the economic disruption that could otherwise arise from the need for subsequent reductions at historically unprecedented rates, should near-term action remain inadequate.”

Read the full paper on the Nature Geoscience website. 

Media highlights 

Ambitious 1.5C Paris climate target is still possible, new analysis shows - The Guardian 

Limiting global warming to 1.5 °C may still be possible - Nature 

Global warming may be occurring more slowly than previously thought, study suggestsThe Independent

Paris climate aim 'still achievable - BBC News

Limiting Global Warming to 1.5 Degrees Celsius May Still Be Possible - Scientific American