Hot Topics

 ©Sarah Depper, CC BY 2.0
©Sarah Depper, CC BY 2.0

Since 2009 over a hundred Small Island Developing States, Least Developed Countries and many others have been calling for limiting global temperature rise to below 1.5°C above pre-industrial levels. Placing the 1.5°C limit alongside the legally binding goal to hold global temperatures “well below 2°C above pre-industrial levels” in the Paris Agreement was a major victory for vulnerable countries. This page is an information pool for material around the 1.5°C temperature limit. It covers these questions:

  • Why 1.5°C? Science, impacts and risks
  • What will it take to limit warming to 1.5°C?
  • What are the emissions reduction targets and 1.5°C pathways?


17 Dec 2015
Turning up the heat: how the diplomatic push for 1.5°C unfolded in Paris
The inclusion of a 1.5°C temperature limit in the new Paris climate agreement was a major victory for the poorest countries and island nations who came to Paris saying they wanted the world to act.
By placing the 1.5°C limit alongside the legally binding goal to hold global temperatures “well below 2°C above pre-industrial levels”, the deal offered hope to the many who had begun to despair about the prospects of an ambitious enough global climate agreement ever being reached.

Why 1.5°C? Science, impacts and risks

1.5°C risks and feasibility – key points

This fact sheet provides key points on risks to ecosystems, food security and sustainable development associated with 1.5°C warming. It also provides responses to arguments commonly made against 1.5°C and provides the scientific evidence for each point made.

How hot is too hot?

This blog explains the process and outcomes of the Structured Expert Dialogue (SED). It summarises the SED key messages and discusses consequences for the negotiations process.

Is it possible to return warming to below 1.5˚C within this century?

This briefing comments on the feasibility of holding warming below 1.5°C within this century and provides information on selected climate risks at 1.5°C, 2°C and 4°C warming.

Climate Impacts at 1.5°C and 2°C – A Pacific Perspective

This is short summary the key climatic risks for the Pacific region at 1.5°C and 2°C warming.

Impacts of climate change on Pacific Islands – A Science Update

This briefing paper summarises the knowledge on impacts of climate change for the Pacific region.

More Hot Topics

The Paris Agreement has a double threshold of 55 countries and 55% of global emissions that must both be met before it enters into force and becomes legally binding. It opened for signature on 22 April 2016. Climate Analytics tracks the progress of ratification on this page.  
This page outlines the scientific, technical and economic feasibility of holding warming well below 2°C, and below 1.5°C by 2100. It addresses the consequences of limited climate action to date, it discusses implications for the negotiations on a new climate agreement in Paris, and it reviews some critical mitigation options, like decarbonization, renewables, bio-energy, carbon capture and storage, and the combination of the latter two – BECCS.  
2°C limit is too warm for many vulnerable systems and regions, and a 1.5°C limit would be significantly safer. Antarctic ice shelf loss comes from underneath.