President Obama hailed the approval of a far-reaching global climate accord to limit greenhouse gas emissions adopted Saturday in Paris, in a statement from the White House Cabinet Room Saturday afternoon.

Praising the pact as a ‘turning point for the world,’ Obama commended leaders from more than 190 countries for working together “to show what is possible when the world stands as one.”

Leaders of the many nations involved had been negotiating the pact for four years after earlier attempts to reach such a deal failed.

Loud applause shook the large Paris conference hall where the talks were being held after French Foreign Minister Laurent Fabius gaveled final approval of the agreement earlier in the day. Some delegates started crying. Others embraced.

“In short, this agreement will mean less of pollution that threatens our planet. Full implementation of this agreement and will pave the way for more progress in stages over the years. It sends a powerful signal: a low carbon future, in clean energy at a scale we have never seen before.” Obama said.

The pact, known as “the Paris agreement,” is supposed to take effect in 2020 and strives to limit global temperature rise even more, to 1.5 degrees Celsius.

Sky News reported that countries most vulnerable to climate change had lobbied for the 1.5C limit while big polluters such as China, India and Saudi Arabia preferred 2C.

In his remarks, Obama also hit back at critics and “skeptics [who] said these actions would kill jobs.”

“Instead…we have driven our economic output to all-time highs in nearly two decades.”

“All countries have a role to play in climate change, wind and solar [energy] …creating a new and steady stream of middle class jobs,” Obama said.

Responding to the climate pact’s approval, Senate Majority Leader Mitch McConnell, R-Ky., called its goals “unattainable,” and slammed Obama’s claims about what the international deal would achieve:

“The President is making promises he can’t keep, writing checks he can’t cash, and stepping over the middle class to take credit for an ‘agreement’ that is subject to being shredded in 13 months,” the Senate’s top Republican, and a staunch Obama critic, said in a statement released following the speech.

Secretary of State John Kerry praised the new accord as a "victory for all of the planet and for future generations."

Kerry told fellow negotiators Saturday in Paris that "it will help the world prepare for the impacts of climate change that are already here and also for those that we already know are on our way inevitably."

He added the pact would "prevent the worst most devastating consequences of climate change from ever happening."

The vote to adopt the agreement was held up for two hours because of a last-minute snag involving the U.S., the Associated Press reported, citing a Western diplomat as its source.

The diplomat said the U.S. wanted the word "shall" changed to "should" in a clause on emissions targets out of fears that it might require the Obama administration to seek approval from the Republican-controlled Senate.

Hours earlier, Fabius said the climate talks would be a “historic turning point” if delegates were to adopt the final draft as presented by the French government.

The deal on climate change will limit warming to “well below” 2 degrees Celsius (3.6 degrees Fahrenheit), Fabius said, according to Sky News.

“The world is holding its breath, it’s counting on all of us,” the minister added.

In the pact, the countries pledge to limit the amount of greenhouse gases emitted by human activity to the same levels that trees, soil and oceans can absorb naturally, beginning at some point between 2050 and 2100.

In practical terms, achieving that goal means the world would have to stop emitting greenhouse gases -- most of which come from the burning of oil, coal and gas for energy -- altogether in the next half-century, scientists said. That's because the less we pollute, the less pollution nature absorbs.

Achieving such a reduction in emissions would involve a complete transformation of how people get energy, and many activists worry that despite the pledges, countries are not ready to make such profound and costly changes.

The deal now needs to be ratified by individual governments -- at least 55 countries representing at least 55 percent of global emissions -- before taking effect.

Negotiators had a few hours to analyze the draft before the vote to adopt it took place. French President Francois Hollande, who joined the meeting Saturday to underscore the deal’s importance, urged approval.

“The decisive agreement for the plant is here and now,” Hollande said. “France calls upon you to adopt the first universal agreement on climate.”

An air of optimism surrounded the negotiations late Friday that had been missing only hours earlier.

"We are pretty much there," Egyptian Environment Minister Khaled Fahmy, the chairman of a bloc of African countries, told The Associated Press late Friday. "There have been tremendous developments in the last hours. We are very close."

A top climate scientist who was critical of draft negotiation texts on Friday has praised the final draft as being consistent with science.

John Schellnhuber, director of Germany's Potsdam Institute for Climate Research, says that "if agreed and implemented, this means bringing down greenhouse-gas emissions to net zero within a few decades."

He says the accord presented Saturday "is in line with the scientific evidence we presented of what would have to be done to limit climate risks such as weather extremes and sea-level rise. To stabilize our climate, CO2 emissions have to peak well before 2030 and should be eliminated as soon as possible after 2050."

The draft removes controversial terms like "climate neutrality" or "emissions neutrality" which had appeared in earlier drafts but were met with opposition from countries including China.

The deal marks the world’s first comprehensive climate agreement with all countries, not just wealthy ones, taking action to tackle global warming.

The agreement comes after more than two decades of U.N. efforts to persuade governments to work together to reduce the man-made emissions that scientists say are warming the planet. Melting glaciers, rising seas and expanding deserts linked to such climate change are threatening populations around the world, the Associated Press reported.

Activists held protests across Paris on Saturday, demanding even tougher limits and to call attention to populations threatened by climate change.

"This puts the fossil fuel industry on the wrong side of history," said Kumi Naidoo of Greenpeace. "This deal alone won't dig us out of the hole we're in."

The world has already warmed by about 1 degree Celsius since pre-industrial times, and poor low-lying nations have pushed to set a goal of limiting the rise to another half-degree on top of that.

Ben Strauss, a sea level researcher at Climate Central, said limiting warming to 1.5 degrees instead of 2 degrees could potentially cut in half the projected 280 million people whose houses will eventually be submerged by rising seas.

The previous emissions treaty, the 1997 Kyoto Protocol, included only rich countries and the U.S. never signed on. The last climate summit, in Copenhagen in 2009, ended in failure when countries couldn't agree on a binding emissions pact.

Fox News' Chad Pergram, Wes Barrett and the Associated Press contributed to this report.

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