Emissions of the most common greenhouse gas could dip this year, according to new figures released at the UN's climate change summit.
It would be the first time that carbon dioxide pollution has fallen during a period of strong global economic growth.
Projections from the University of East Anglia (UEA) and the Global Carbon Project suggest emissions will drop by 0.6% this year.
Prof Corinne Le Quere, director of the UEA's Tyndall Centre, said much of the decline was due to China, which tops the emissions league table, reducing the amount of coal it burns. Emissions there are expected to drop by almost 4% this year.
"Whether a slower growth in global emissions will be sustained depends on the use of coal in China and elsewhere, and where new energy will come from," she said.
"In 2014, more than half of new energy needs in China were met from renewable sources such as hydro, nuclear, wind, and solar power."
Emissions in the EU and US are also projected to fall in 2015. But they are rising steeply in India, as the country builds more coal power stations to fuel it's economic expansion.
Nevertheless, the findings raise hopes that emissions are nearing a peak - and that carbon dioxide pollution can be 'de-coupled' from future economic growth.
Emissions have been rising by 2-3% a year since 2000. But last year production slowed to just 0.6% and that downward trend has continue into 2015, according to figures published in the journal Nature Climate Change.
Global economic growth rose by 3% in both 2014 and 2015.
Prof Le Quere said: "It looks like the trajectory of global emissions might have changed temporarily. It is unlikely that emissions have peaked for good. This is because energy needs for growing economies still rely primarily on coal, and emissions decreases in some industrial countries are still modest at best.
"Global emissions need to decrease to near zero to achieve climate stabilisation. We are still emitting massive amounts of CO2 annually - around 36bn tonnes from fossil fuels and industry alone. There is a long way to near-zero emissions."
Government ministers from around the globe are meeting in Paris to negotiate a deal to cut carbon emissions to zero by the end of the century, in an attempt to cap the rise in the average global temperature to 2 degrees.
Prof David Reay, Professor of Carbon Management at the University of Edinburgh, said: "Be in no doubt, there is a long, long way still to go.
"To stay within the 2 degrees global warming target, emissions can't just stall. They need to fall.
"Whether 2015 is the year we truly turn the corner on global emissions or is just a blip in the upward march towards dangerous climate change now depends on Paris."
Tim Osborn, a climate researcher at UEA, said: "Lower-than-expected CO2 emissions in 2015 are welcome, but 2015 emissions are still higher than in every year up to 2013 and CO2 is still accumulating in the atmosphere because we are adding it (through our emissions) more quickly than natural processes are able to remove it from the atmosphere and store it in the oceans and forests."