The Glasgow Climate Pact puts the world in its best position yet to tackle climate change, the Biden administration's special presidential envoy for climate, John Kerry, said Saturday.

“I really do believe that as a result of this decision, and as a result of the announcements that have been made over the course of the last two weeks, we are in fact closer than we have ever been before to avoiding climate chaos and securing cleaner air, a safer water and healthier planet,” Kerry said during a press conference at COP26.

He said Glasgow was never the finish line in the fight to stop climate change and anyone who thought COP26 would result in one decision to end the climate crisis doesn't understand the enormity of the problem.

“I would say that, you know, Paris built the arena and Glasgow starts the race. And tonight, the starting gun was fired,” Kerry said.

Even though Congress is struggling to pass legislation that would enable the country to meet President Biden’s climate goals, Kerry said he has faith this momentum to save the planet will continue.  

-ABC News' Stephanie Ebbs

On the heels of COP26 delivering the Glasgow Climate Pact, some environmentalists and activists are mildly praising world leaders for agreeing to phase out fossil fuels, while others called the summit a failure for not going far enough. 

"The #COP26 is over. Here’s a brief summary: Blah, blah, blah," teen climate activist Greta Thunberg tweeted, repeating a criticism she made early on. "But the real work continues outside these halls. And we will never give up, ever."

Ani Dasgupta, president and CEO of World Resources Institute, called the decision a strong foundation to build on, but the real test will be whether countries implement everything they promised in Glasgow and if developed countries will meet their financial commitments.

"The train is moving and all countries need to get on board," he said in a statement. "As attention shifts beyond COP26, it’s critical for everyone to step up their efforts and turn commitments into real action in ways that benefit all people."

The Nature Conservancy said that if Paris established the "scaffolding" of global climate action, Glasgow is the foundation -- but there’s a lot of heavy lifting still to be done.

“Despite suggestions to the contrary, I believe we can leave COP26 with some hope still intact," Nature Conservancy Director of International Climate Policy John Verdieck said in a statement. "It is imperative, as we look towards COP27 in Egypt and the threats facing its African neighbors, that on-the-ground implementation of proven climate strategies accelerates this year."

Jennifer Morgan, the executive director of Greenpeace, called the text "meek" and "weak" and said it could have been even weaker if it wasn’t for young people speaking out.

Rachel Cleetus, policy director and lead economist for climate and energy at the Union of Concerned Scientists, said countries ultimately failed to deliver everything they promised in the final document and specifically criticized the U.S.

“Richer countries -- including the United States -- had a chance to be climate champions, but instead evaded their historical responsibility and prioritized the profits of fossil fuel polluters over the needs of people on the frontlines of the climate crisis," she said in a statement.

Others said the COP26 decision doesn’t mean much if President Biden doesn’t take stronger action to end the use and development of fossil fuels in the U.S.

“We made it plain that President Biden can use the power of his pen to stop the toxic buildout in the Gulf and across the country. If we’re in code red, as Biden says we are, he’s got to act now to stop the crisis,” said John Beard, CEO of Port Arthur Community Action Network and a member of the Build Back Fossil Free coalition.

-ABC News' Stephanie Ebbs

COP26 has officially adopted the Glasgow Climate Pact, a 10-page document that lays out the groundwork for how the world will attempt to prevent the worst impacts of climate change.

Nearly 200 countries agreed on the importance of addressing climate change but deep divisions still remained about the future of fossil fuels and rich countries' reluctance to provide full-fledged financial support to countries more vulnerable to the impacts of climate change.

Representatives from several countries said the pact did not go far enough to address the climate crisis but they could not justify leaving Glasgow without any progress on the issue.

-ABC News' Stephanie Ebbs

Despite being the last stipulated date for the COP26, country representatives continue to work on finalizing the draft of the Glasgow deal. The negotiations are expected to continue into the night.

Countries continue to dispute who bears the financial burden of climate action and the deadlines for carbon emissions reductions. Some disagreements also took place over the semantics of the draft as representatives argued over whether "requests" or "urges" was a better fit when talking about climate goals.

The final day also witnessed walkouts and protests from climate activists around the world who claimed their voices were not being heard.

Crowds outside chanted: "Fighting for justice, and for liberation."

On his second day at COP26, Biden outlined the United States’ plan to join the world in its mission to reduce deforestation.

“Preserving forests and other ecosystems can and should play an important role in meeting our ambitious climate goals as part of the net-zero emissions strategy we all have,” Biden said.

The plan has four components: to incentivize restoration and conservation, to encourage private sector investment, to increase data collection and accountability and to meet a $9 billion U.S. funding goal through 2030 – subject to approval by Congress.

Biden hopes this plan will restore 200 million hectares of forest and other ecosystems by 2030.