The Paris Agreement is a landmark international treaty adopted at the 2015 United Nations Climate Change Conference (COP21) in which 195 countries agreed to a framework for reducing greenhouse gas emissions and limiting the global temperature rise to well below 2 degrees Celsius above pre-industrial levels, while pursuing efforts to limit warming to 1.5 degrees.
To achieve these targets, the Agreement operates on a five-year cycle of increasingly ambitious climate action. Every five years, each participating nation must submit an updated individual plan, known as a Nationally Determined Contribution (NDC), detailing exactly how it will cut emissions and adapt to climate change. While the treaty legally obligates countries to report their progress transparently, the actual emission targets are set voluntarily, creating a system of global peer pressure rather than enforceable international penalties.
Although the Agreement originally emphasized keeping warming well below 2 degrees Celsius, subsequent climate science has driven an urgent global focus on the stricter 1.5-degree target. A landmark 2018 report by the Intergovernmental Panel on Climate Change (IPCC), the United Nations body that assesses climate science, found that allowing global warming to reach 2 degrees, instead of limiting it to 1.5, would expose hundreds of millions more people to extreme heatwaves, accelerate sea-level rise and lead to the near-total loss of the world's tropical coral reefs. As a result, international climate discussions increasingly frame 1.5 degrees as critical for vulnerable island nations and coastal communities.
Despite these warnings, a significant gap remains between international commitments and real-world action. Nations have struggled to meet their targets due to economic pressures, political shifts and the complex dynamics of international financial support for developing countries. For example, the United States, the world's second-largest greenhouse gas emitter, officially withdrew from the agreement on January 27, 2026, following an executive order signed by President Donald Trump.
Additionally, many rapidly developing countries argue they must rely on inexpensive fossil fuels to lift their populations out of poverty, while discussions over climate funding remain a point of tension between wealthier and poorer nations. Although developed countries finally met and surpassed their baseline pledge of $100 billion annually in 2022, international negotiations have shifted toward an ambitious new global framework to triple climate finance to $300 billion per year by 2035.
Because the agreement relies primarily on transparency and peer pressure rather than enforceable penalties, its success ultimately depends on whether the remaining countries strengthen their commitments over time and follow through on them.