Historical Progress

The 2015 Paris Agreement was negotiated six years after the failed climate talks in Copenhagen in 2009. High-level diplomatic efforts helped bridge deep political divides – especially among major economies with contrasting histories, emissions profiles, and levels of development – and sought to address the unique vulnerabilities of small island states, least developed countries and other affected nations.

The Paris Agreement aims to limit global warming to 1.5°C and reach net zero greenhouse gas emissions worldwide in the second half of this century. The 2025 International Court of Justice Advisory Opinion on climate change anchors the 1.5°C temperature limit as the central target of the Paris Agreement for all countries, noting they are obligated to work towards the highest possible ambition for their national determined contributions (NDCs).

With overshoot of 1.5°C likely by 2030 given the lack of action to date, it’s important to recognise that the 1.5°C limit remains the scientifically grounded and legally significant temperature goal. The 1.5°C limit emerged from post-Copenhagen negotiations, which found that the former 2°C goal was unsafe. Since 2015, the IPCC and a growing body of scientific research have reinforced the benefits and urgency of the 1.5°C threshold. It is now seen as a key planetary boundary beyond which extreme events and tipping points will become very dangerous.

Alongside the Paris Agreement’s net zero goal, the 1.5°C limit provides the scientific and technical basis to designing policies that will limit the magnitude and duration of any temporary overshoot of 1.5°C, while driving global emissions down to net zero as fast as possible.

The CAT has been tracking the impact of government targets and policy action against end-of-century global warming since Copenhagen in 2009. In line with the objectives of the Paris Agreement, countries submitted Nationally Determined Contributions (NDCs) and Long-Term Strategies (LTS) that should embody their “highest possible ambition” to align with the 1.5°C temperature limit.