Data from the International Energy Agency (IEA) indicates that global emissions of carbon dioxide from the energy sector stalled in 2014.
It marks the first time in 40 years in which there was a halt or reduction in emissions of the greenhouse gas that was not tied to an economic downturn.
Chief economist Fatih Birol said: “This gives me even more hope that humankind will be able to work together to combat climate change, the most important threat facing us today”.
Global emissions of carbon dioxide stood at 32.3 billion tonnes in 2014, unchanged from the preceding year.
The preliminary IEA data suggests that efforts to mitigate climate change may be having a more pronounced effect on emissions than had previously been thought.
It attributes the halt in emissions growth to changing patterns of energy consumption in China and OECD countries.
In China, 2014 saw greater generation of electricity from renewable sources such as hydropower, solar and wind, and less burning of coal.
In OECD economies, efforts to promote more sustainable growth – including greater energy efficiency and more renewable energy – are producing the desired effect of decoupling economic growth from greenhouse gas emissions.
“This is both a very welcome surprise and a significant one,” added Mr Birol. “It provides much-needed momentum to negotiators preparing to forge a global climate deal in Paris in December: for the first time, greenhouse gas emissions are decoupling from economic growth.”
In the 40 years in which the IEA has been collecting data on carbon dioxide emissions, there have only been three times emissions have stood still or fallen compared with the previous year and all were associated with global economic weakness: the early 1980s; 1992 and 2009.
In 2014, however, the global economy expanded by 3%.
More details on the data and analysis will be included in an IEA special report on energy and climate that will be released on 15 June.
“The latest data on emissions is indeed encouraging, but this is no time for complacency – and certainly not the time to use this positive news as an excuse to stall further action,” said executive director Maria van der Hoeven.