The Paris Agreement is an international treaty on climate change adopted on the 12th of December 2015 by 195 nations and the European Union. It sets a long-term goal of limiting global average temperature rise to well below 2 degrees Celsius above pre-industrial levels, with efforts to limit the increase to 1.5 degrees. Each participating country submits its own emissions reduction plan, called a nationally determined contribution, which must be updated every five years.
When did the Paris Agreement enter into force?
The Paris Agreement entered into force on the 4th of November 2016. It became effective after the European Union ratified it, giving the agreement enough parties to meet its threshold of 55 countries representing at least 55 percent of global greenhouse gas emissions.
How many countries have signed the Paris Agreement?
As of January 2026, 194 states and the European Union have signed the Paris Agreement, together representing over 98 percent of global greenhouse gas emissions. The three UNFCCC member states that have not ratified are Iran, Libya, and Yemen.
Why did the United States withdraw from the Paris Agreement?
The United States has withdrawn from the Paris Agreement twice. The first withdrawal, initiated by the Trump administration on the 4th of August 2017, took effect on the 4th of November 2020, with concerns about the agreement's legally binding nature and national sovereignty cited in public debate. The United States rejoined on the 20th of January 2021 under President Biden, then withdrew again under President Trump's executive order on the 20th of January 2025, with that withdrawal taking effect on the 27th of January 2026.
Is the Paris Agreement legally binding?
The Paris Agreement is a binding treaty, but its emissions targets are not legally enforceable. Each country sets its own nationally determined contributions, and there is no mechanism to compel a specific target or penalize failure to meet one. Only the reporting and review procedures carry legal force under international law.
Has the Paris Agreement been used in court cases?
Yes. The Paris Agreement has been used successfully in climate litigation. In 2019, the Dutch Supreme Court upheld a ruling requiring the Netherlands to maintain its emissions reduction targets, using the agreement's 2-degree target as part of the legal basis. In May 2021, the district court of The Hague ordered Royal Dutch Shell to cut its global emissions by 45 percent from 2019 levels by 2030, marking the first major application of the Paris Agreement against a corporation. In 2022, Brazil's Supreme Federal Court recognized the agreement as a human rights treaty that supersedes national law.