Limiting overshoot - Navigating exceedance of 1.5°C and pathways towards return

The report explores the risks and impacts associated with higher levels of warming, the mitigation pathways needed to limit peak warming and enable temperatures to decline, and how adaptation and development approaches must respond to changing conditions along an overshoot, peak and decline pathway.

Key messages emerging from the report include:

1. Despite some progress on addressing climate change, global temperature rise is set to cross 1.5°C above pre-industrial levels, likely within the next few years. There are no good outcomes in remaining above 1.5°C.
2. Following an ‘overshoot, peak and decline’ pathway is the best remaining option to bring temperatures to or below 1.5°C by the end of the century, which remains the goal, and adapt to unavoidable impacts.
3. Rapid, collective and global action is vital: lower peak warming and shorter exceedance duration will reduce risks and impacts, make efforts to help communities cope less difficult and less expensive, and increase the chances of bringing temperatures back down.
4. Equity and justice must form the core of strategies to protect the vulnerable, create a just transition and secure a liveable future for coming generations.
5. Mitigation and adaptation are interconnected and mutually reinforcing. They must advance together, while being responsive to emerging risks.
6. Carbon Dioxide Removal (CDR) – the process of removing carbon from the air and storing it through afforestation or other means – will be needed in addition to, not instead of, sustained reductions in greenhouse gas emissions, but these methods come with risks and trade-offs that limit their potential and need to be carefully governed.
7. A return to or below 1.5 is uncertain. Even if a return to below 1.5°C is secured, many nations and communities will face irreversible losses and permanently changed conditions. This raises issues of justice, power and political legitimacy, which will require new, inclusive governance arrangements.