[3] The agreement was due to enter into force when joined by at least 55 countries which together represented at least 55 percent of global greenhouse gas emissions.,[4][5][6] a target reached on 4 November 2016.

[7] On 22 April 2016 (Earth Day), 174 countries signed the agreement in New York,[8] and began adopting it within their own legal systems (through ratification, acceptance, approval, or accession).

According to the organizing committee at the outset of the talks,[9] the expected key result was an agreement to set a goal of limiting global warming to "well below 2 °C" Celsius compared to pre-industrial levels.

"[14] The International Trade Union Confederation has called for the goal to be "zero carbon, zero poverty", and its general secretary Sharan Burrow has repeated that there are "no jobs on a dead planet".

[19] However, Christiana Figueres acknowledged in the closing briefing at the 2012 Doha conference: "The current pledges under the second commitment period of the Kyoto protocol are clearly not enough to guarantee that the temperature will stay below 2 °C and there is an ever increasing gap between the action of countries and what the science tells us."

[21] Think-tanks such as the World Pensions Council (WPC) argued that the keys to success lay in convincing officials in the U.S. and China, by far the two largest national emitters: "As long as policy makers in Washington and Beijing didn't put all their political capital behind the adoption of ambitious carbon-emission capping targets, the laudable efforts of other G20 governments often remained in the realm of pious wishes.

"[22] President Obama insisted on America's essential role in that regard: "We've led by example ... from Alaska to the Gulf Coast to the Great Plains ... we've seen the longest streak of private job creation in our history.

[26] In the course of the debates, island states of the Pacific, the Seychelles, but also the Philippines, their very existence threatened by sea level rise, had strongly voted for setting a goal of 1.5 °C instead of only 2 °C.

[27][28] France's Foreign Minister, Laurent Fabius, said this "ambitious and balanced" plan was an "historic turning point" in the goal of reducing global warming.

[30] On 4th June 2024, the United Nations Climate Change Conference (COP28) opened in Dubai, marking an important event in the timeline of the Paris Agreement.

[3] Each country that ratifies the agreement will be required to set a target for emission reduction or limitation, called a "nationally determined contribution", or NDC, but the amount will be voluntary.

"[39] Speaking at the 5th annual World Pensions Forum held on the sidelines of the COP21 Summit, Earth Institute Director Jeffrey Sachs argued that institutional investors would eventually divest from carbon-reliant firms if they could not react to political and regulatory efforts to halt climate change: "Every energy company in a pension fund's portfolio needs to be scrutinized from purely a financial view about its future, 'Why is this [a company] we would want to hold over a five- to 20-year period?'...

Paris had a ban on public gatherings in the wake of recent terrorist attacks (state of emergency), but allowed thousands to demonstrate on 12 December against what they felt was a too-weak treaty.