Zero in on remaining carbon budget and decadal warming rates

ZERO IN Report 3

Our third ZERO IN report shows how the chances of global temperature rise staying within 1.5°C this century could range from around 75% to less than 30%, depending on how the climate system responds.

We therefore need to look at the range of temperature projections provided by climate models, rather than just single best estimates, when assessing our chances of keeping warming below a certain temperature. This doesn’t mean that it will be harder to stay within 1.5°C than we thought – instead, it shows that, alongside different emissions pathways, complex climate processes could lead us to different climate futures.

The overall message is that, instead of focusing on a single estimate of future temperature change, we need to prepare for a range of eventualities. The more we are aware of these eventualities, the better we can plan for what lies ahead.


About Constrain

The 2015 Paris Agreement sets out a global action plan to avoid dangerous climate change by limiting global warming to well below 2°C, whilst pursuing efforts to limit warming to 1.5°C. However, predicting how the climate will change over the next 20-50 years, as well as defining the emissions pathways that will set and keep the world on track, requires a better understanding of how several human and natural factors will affect the climate in coming decades. These include how atmospheric aerosols affect the Earth's radiation budget, and the roles of clouds and oceans in driving climate change.

The EU-funded CONSTRAIN project, a consortium of 14 European partners, is developing a better understanding of these variables, feeding them into climate models to reduce uncertainties, and creating improved climate projections for the next 20-50 years on regional as well as global scales. In doing so, CONSTRAIN will take full advantage of existing knowledge from the Sixth Phase of the Coupled Model Intercomparison Project (CMIP6) as well as other Horizon 2020 and European Research Council projects.