China's energy-related carbon dioxide (CO2) emissions declined by 1.5 percent in 2015, marking the largest decrease in volumes compared to other countries, International Energy Agency (IEA) Executive Director Fatih Birol?said?on Wednesday.

"China's emissions decline is mainly driven by a reduction in coal use," Birol said.?

He pointed out that China's economic restructuring towards less energy-intensive industries and the government's efforts to decarbonize electricity generation pushed coal use down.

In 2015, coal generated less than 70 percent of Chinese electricity, 10 percentage points less than in 2011. Over the same period, low-carbon sources jumped from 19 percent to 28 percent, with hydro and wind accounting for most of the increase, according to IEA.

Global energy-related carbon dioxide emissions -- the largest source of man-made greenhouse gas emissions -- stayed flat for a second year in a row, according to analysis of preliminary data for 2015 released by IEA.

"The new figures confirm last year's surprising but welcoming news. We now have seen two straight years of greenhouse gas emissions decoupling from economic growth," said Birol. "Coming just a few months after the landmark COP21 agreement in Paris, this is yet another boost to the global fight against climate change."

Global emissions of carbon dioxide stood at 32.1 billion tons in 2015, having remained essentially flat since 2013, according to IEA.

In the more than 40 years in which the IEA has been providing information on CO2 emissions, there have been only four periods in which emissions stood still or fell compared to the previous year. Three of those -- the early 1980s, 1992 and 2009 -- were associated with global economic weakness.

But the recent stall in emissions comes amid economic expansion. According to the International Monetary Fund, global GDP grew by 3.4 percent in 2014 and 3.1 percent in 2015.

"It is very good news that global emission is flat. We see a major contribution coming from China. It is mainly because of Chinese government's efforts to push renewable energies and other clean energies technologies," Birol noted.

"The policies have been designed and successfully implemented by China's government," he said.

"China's energy structure in the future will be much more diverse than it is now. The major energy in China is coal and oil in last few years. Now we are going to see less coal, but more renewable energies, more natural gas and more nuclear power," he indicated.

"I hope to see China's targets in the new five-year plan can be implemented successfully. I also hope to see China emissions will decrease sequentially," Birol said.

Xinhua contributed to the story.