The International Energy Agency (IEA) released its annual “World Energy Outlook” report. Among the most interesting statistics was that almost half of new power plants built worldwide in 2014 were built to utilize renewable energy. The IEA claimed that this is “clear sign that an energy transition is underway.”

According to the Agency, this expansion puts renewable energy as the second largest source of electricity in the world, behind coal. Based on this trend, green energy is expected to overtake coal as the leading source of electricity production by the 2030s.

The IEA predicts that coal usage, despite expansion over the past decade –largely due to China’s growth– will decline in the years ahead: “Coal has increased its share of the global energy mix from 23% in 2000 to 29% today, but the momentum behind coal’s surge is ebbing away and the fuel faces a reversal of fortune.”  But while the report predicts China’s usage will plateau, other Asian and developing countries will continue to increasingly need coal.

While the figures seem promising for green energy advocates, the IEA urges against complacency. The Agency warns that the world is still on the path towards 2.7C of global warming, a dangerous level. The report states that low prices may weed out alternative producers and concentrate supply in the hands of the largest producers. Low prices also undermine efforts to promote efficiency.

Fatih Birol, Executive Director of the IEA, stated that “Now is not the time to relax. Quite the opposite: a period of low oil prices is the moment to reinforce our capacity to deal with future energy security threats.”