The History of International Climate Agreements

Climate change is a global challenge requiring long-term collaboration on both national and international levels. While international negotiations can be slow and cumbersome, they establish an important framework for global climate protection and emissions reduction.

The timeline in the infographics highlights the most important global and European events in climate policy. It begins with the First World Climate Conference in 1979 and extends to the European Climate Law and annual Conferences of Parties (COPs), where world leaders meet to negotiate further progress following the Paris Agreement.

What is IPCC and how does it work?

The Intergovernmental Panel on Climate Change (IPCC) is a body of experts from 195 countries who review the latest research and publish comprehensive Assessment Reports roughly every six to seven years. Rather than conducting new research, the IPCC synthesizes the most reliable scientific findings to provide a robust evidence base for policymakers. These reports describe current trends and provide critical data on mitigation (reducing emissions) and adaptation (adjusting to change). Most modern climate strategies, including those of the EU, are informed by the IPCC’s conclusions.

What is the Paris Agreement and why is it important?

Adopted in 2015, the Paris Agreement has achieved near-universal adoption. While almost every nation has signed and ratified the treaty (the only exceptions are Iran, Libya, and Yemen), the United States occupies a unique position, having withdrawn in 2020, rejoined in 2021, and withdrawn again in early 2026.

The long-term goal of the agreement is to keep the rise in global average temperature to well below 2 °C above pre-industrial levels and pursue efforts to limit the increase to 1.5 °C (See also: How Much Is the Planet Warming?.). While many experts now consider the 1.5 °C target out of reach, the 2 °C target can still be achieved. Every tenth of a degree of warming prevented is vital for climatic stability, the health of ecosystems, and for the livelihoods of those who depend on them (See also: Climate Tipping Points.).

The agreement is a legally binding international treaty. Under its framework, each country is required to develop its own climate action plan with specific targets for emissions reduction and adaptation. These plans must be updated every five years with increasing ambition, aiming for global Net Zero emissions in the second half of this century.

When the first round of targets was submitted to the UN in 2015, it was estimated that if all were fully implemented, the temperature increase would be only limited to about 3-3.5 °C above pre-industrial levels by 2100. As of the end of 2025, if all updated targets were implemented, the projected temperature increase dropped to about 2.3-2.5 °C according to UNEP.¹ Over the ten years since the Paris Agreement, projected warming has fallen significantly – but both ambition and implementation still fall short of its ultimate goals. (See also: Future Warming Estimates.).

Footnotes

1. See in detail United Nations Environmental Programme. (2025). Emissions Gap Report 2025. DOI: 10.59117/20.500.11822/48854. ↩