One option floated by Trump administration officials vying to remain in the accord has been to weaken the USA target.
However, policy changes in China and India could soften that impact.
Various reports have stated that the Administration would like to make a decision about remaining in the Paris Agreement prior to the G-7 and G-20 summits in May. The negotiations also approved a draft 2018-19 budget for the United Nations climate change secretariat despite uncertainties about the USA contribution.
A State Department official said in an emailed statement that the Trump administration was "reviewing the United States' global climate change policies" and had no decisions to announce.
India and China are on track to do better on their respective pledges to cut greenhouse gas emissions under the Paris Accord, so much so that they may be able to compensate globally for the imminent failure of the U.S. to deliver because of President Donald Trump's rollback of mitigation measures initiated by his predecessor Barack Obama. Also, several U.S. states, including California and NY, remain committed to the targets of the Clean Power Plan and are even trying to exceed them.
The White House website describes Trump's climate plan this way.
"As long there is a chance to stop global warming at a level that lets humanity survive and thrive, we should seize it", CVF representative Emmanuel De Guzman, a climate commissioner from the Philippines, said on the sidelines of United Nations talks under way in Bonn.
Some in the Trump administration have suggested renegotiating the terms of USA participation.
But the real costs inherent in abiding by Paris, both in direct compliance costs and from costs ensuing from lost opportunity (those redirecting resources away from productive investments), are truly staggering.
"He is very open in repeating "our position is under review" but he is actively engaged and participating in the discussions and I think that his attitude has been appreciated".
"We moved on without the USA", said Gebru Jember Endalew of Ethiopia, who chairs the 48-nation group of least developed nations that are among those at risk from more heatwaves, floods and rising seas. The "rule book" the Bonn participants started work on is meant to guide countries in implementing the Paris Agreement's goals - what type of information to include in their emissions-curbing updates, for example. And India has pledged to boost its non-fossil fuel energy share to at least 40 percent by 2030.
Advancing efforts on the transparency framework, such as how to report national greenhouse gas emissions inventories, what information is necessary to track progress on countries' climate actions and what information should be provided on financial support, technology transfer and capacity-building. The new analysis suggests they will leap past that mark to a 42 to 45 percent cut in emissions intensity by 2030. Additionally, the country is implementing policies to boost renewable energy capacity and reduce coal imports, which CAT believes could "see a significant slowing down in the growth of Carbon dioxide emissions over the next decade".
But after years of taking the lead in talks for a global pact and making tough choices to lessen reliance on fossil fuels at home, the 28-member bloc's resolve now seems to be flagging, analysts say.
And China - the world's greatest consumer of coal and emitter of greenhouse gases - has now seen three consecutive years of declining coal consumption.
"The US role can not be filled by China", he said, "just like China's role can not be replaced by the United States". I would love for nothing more than India to truly lead global climate action. The UNFCCC Secretariat has requested nearly 59 million euros (US$65 million) for the two years - an increase of 9.7 per cent.
It is also planning for a non-coal future based on renewables.
United Nations top climate officials have called for the commitment of contracting parties to the Paris Agreement on Thursday.