The pact has strong international support but whether or not it will be effectively implemented remains to be seen.
The Paris climate change agreement aiming to tackle climate change officially came into effect on Friday, increasing the pressure on countries to execute plans to limit global warming by cutting greenhouse gas emissions.
The agreement initially struck in December 2015, with the approval of nearly 200 countries, is considered to be the most complex global treaty since the Marrakesh (trade) Agreement, signed in 1994.
"This is a moment to celebrate. It is also a moment to look ahead with sober assessment and renewed will over the task ahead," climate chief of UN Patricia Espinosa said in a statement.
The ratification of the agreement was quickly done, which is seen as an indication of the strong international support it has, but there are still around 100 countries that have yet to ratify it.
The threshold for entry into force of the agreement was achieved on the 5th of October, with the participation of the 55 nations accounting to more than 55 percent of the greenhouse gas emissions.
"In a short time – and centainly in the next 15 years – we need to see unpredecented reductions in greenhouse gas emissions and unequalled efforts to build socities that can resist rising climate impacts," Espinosa said.
The Paris Agreement seeks to limit the rise in average world temperatures to as low as 1.5 degrees Celsius.
However, according to a recent annual report of UN Environment, the analysed countries' current pledges for emission cuts were insufficient.
The next round of UN climate talks will being on Monday in Marrakesh, Morocco, where participating countries willl try to find ways to adhere to the agreement and work out the rules.
Environmental campaign groups, as well as some businesses, investors and academics said the meeting must keep up the spirit of international support for climate action.
"Even with the commitments made in Paris and encouraging action on the ground, we will not meet our aspiration of limiting warming to 1.5 degrees unless we move faster and at the scale that is needed," World Bank Group President Jim Yong Kim said.