There are "clear signs" a global energy transition is under way, with renewables now the second largest source of electricity, the International Energy Agency (IEA) has said.
In its latest annual world energy outlook, the IEA said renewables such as wind, solar and biomass delivered almost half the world's new power generation in 2014 and are set to become the leading source of new supply between now and 2040.
The clean power technologies are set to overtake coal as the largest source of electricity generation in the 2030s, and by 2040 half of Europe's power will be generated from renewables, about 30% in China and Japan and 25% in the US and India.
Energy efficiency regulations also now cover more than a quarter of global energy consumption.
The changes mean growth in greenhouse gas emissions from energy will slow dramatically, but the world is still on course for a temperature increase of 2.7C (4.86F) by 2100 - above the 2C (3.6F) threshold that governments have agreed to stave off the worst impacts of climate change.
Ahead of crucial climate talks in Paris in a few weeks' time, which aim to agree a new deal to curb the emissions which cause global warming, the IEA said a major course correction was still needed to achieve the 2C goal.
The agency's executive director Dr Fatih Birol said: "As the largest source of global greenhouse gas emissions, the energy sector must be at the heart of global action to tackle climate change.
"World leaders meeting in Paris must set a clear direction for the accelerated transformation of the global energy sector."
The world energy outlook also said that China's coal use, a major source of emissions, is reaching a plateau, as its economy rebalances and energy demand growth slows, before declining, while energy demand in India is on the increase.
All countries are predicted to adopt more energy-efficient technologies, although a long period of lower oil prices could undermine the move to more efficient energy use, according to the IEA.
Overall energy demand is set to grow by nearly a third between 2013 and 2040, with the net growth driven entirely by developing countries.