The energy sector generated 32.3 billion tons of carbon dioxide last year, unchanged from 2013.
Over the last 40 years, the only other times that emissions stayed the same or dropped were during economic crisis in the early 1980s, 1992 and 2009.
The IEA said increasing use of renewable energy, particularly in China and OECD countries, stalled the figures in 2014.
China saw an increase in energy generated 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 renewable energy, have also played an important role.
IEA 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.
"This is both a very welcome surprise and a significant one. 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."
The IEA said it will release additional data and analysis in a special report on energy and climate in June 2015.
Image: The energy sector generated 32.3 billion tons of carbon dioxide in 2014.Photo: Courtesy of worradmu/FreeDigitalPhotos.net.
