In recent months, the key story of international climate policy has been about how quickly countries – including India - will join the Paris agreement, and cross the legal threshold to bring it into force. And as of now, that seems very close to happening.
As soon as it does, though, People will start asking which if any of these countries are on track to do what they've already said they would under the agreement - namely, hit their voluntarily pledged targets to cut their emissions.
And unless the US does more, it will likely miss the emissions target aimed for in the landmark Paris Climate Agreement, says a new study released Monday.
Cutting the emissions of heat-trapping greenhouse gases such as carbon dioxide and methane from power plants and other sources is a key to reducing the impacts of man-made climate change.
Even if all current and proposed emission reduction plans are enacted, the US will still fall short by anywhere from 300 million to as many as 1.5 billion metric tons of greenhouse gas emissions per year, the study found.
"We will likely fall short without additional policies," said lead author Jeffrey Greenblatt of the Lawrence Berkeley National Laboratory.
The additional policies include President Obama's proposed Clean Power Plan - which would trim carbon emissions from coal power plants and other sources - would be a big step in the right direction, Greenblatt said. The plan, however, faces a potentially lengthy court challenge from 28 states and scores of companies and industry groups that begins Tuesday.
Obama formally entered the US into the Paris Agreement earlier this month, which commits the country to reducing emissions by 26 to 28 per cent of 2005 levels by 2025.
The study comes at a key point in US climate policy. Obama has said the US should be a global leader in fighting climate change - a promise that Hillary Clinton wants to continue but one that Donald Trump would likely shun.
Additionally, if Trump is elected, he said he will repeal the Clean Power Plan.
Karl Hausker, a policy analyst at the World Resources Institute who was not involved in the study, said its methodology and findings are credible. He said the next president will have to continue the policies begun by President Obama.
Though the study that came out Monday is solely focused on US emissions, its author said the US is key player in the global fight against climate change.
"It's true that other nations collectively emit much more than the US, but we are one of the world's biggest emitters, right behind China," said Greenblatt. "So reducing our emissions will have a material effect on global totals," he said. "Perhaps more important, however, is that our efforts to reduce emissions can motivate other countries to set similarly ambitious targets."