Renewable energy will pass coal as the largest source of electricity by the early 2030s and reach a 25% share in the U.S. by 2040, but the shift is not coming quickly enough for a permanent reversal of rising carbon emissions, a new report from the International Energy Agency says.

The IEA’s latest World Energy Outlook, released in advance of climate talks opening in Paris later this month, says that there are “unmistakable signs” a global energy transition is underway. But lower carbon emissions connected with the generation of electricity probably won’t be matched in industry and transportation.

The net result is that the rise in carbon emissions will slow down, but not enough to prevent global temperatures from increasing more than 2 degrees Celsius over pre-industrial levels, the point at which scientists think that dangerous climate change is more likely.

“The net result of the changes seen in the [World Energy Outlook-2015] central scenario is that the growth in energy-related emissions slows dramatically, but the emissions trajectory implies a long-term temperature increase of 2.7°C by 2100,” a summary of the report says. “A major course correction is still required to achieve the world’s agreed climate goal.”

Energy demand grows, but coal use declines

The report predicts that world energy demand will grow by nearly a third between 2013 and 2040 even as the importance of coal continues to slide and renewables become a more important part of the mix. Electricity from renewable sources is predicted to hit 50% in the European Union by 2040, around 30% in China and Japan, and more than 25% in the U.S. and India.

Renewables produced almost half of the world’s new power generating capacity in 2014, the report says, and already have become the second largest source of electricity after coal. Renewables will become the leading source of new energy through 2040.

Meanwhile, coal’s share of electricity generation is predicted to drop to 30% by 2040.

The energy sector is the largest single source of greenhouse gas emissions, the IEA says, and must be “at the heart of global action” to control climate change. More than 150 countries have submitted pledges to reduce emissions in advance of the Paris talks, many of which focus on more renewable energy and improved energy efficiency.

Despite the move toward low-carbon generation, however, C02 emissions will still rise by 16% by 2040.

Oil prices are another factor

Continued low prices for oil would benefit consumers, the report says, but also raise stability concerns for the future. The report foresees a price of about $80 a barrel by 2020, but there’s also the chance that prices could stay lower for much longer.

“Lower [oil] prices are not all good news for consumers,” the report’s summary says. “The economic benefits are counterbalanced by increasing reliance on the Middle East for imported crude oil and the risk of a sharp rebound in price if investment dries up. Concerns about gas supply security would also be heightened if prices stay too low to generate the necessary investment in supply.”

Other conclusions:

• India will account for the largest single share of growth in demand. The country accounts for 17% of the world’s population but only 6% of energy use. Twenty percent of its population — 240 million people — have no access to electricity. Demand for coal and oil will surge, although India has pledged to have a 40% share of non-fossil sources for power by 2030.
• The world doesn’t have enough affordable energy. An estimated 1.2 billion people — 17% of the global population — don’t have access to electricity, and 38% of the world’s population puts its health at risk by relying on traditional biomass for cooking.
• Natural gas consumption is growing quickly. While gas “is a good fit for a gradually decarbonizing energy system,” methane leaks in the supply chain will put a dent in its environmental credentials.
• Low-carbon technologies will become more widespread as oil and gas get more expensive to extract and more efficient equipment and and renewable energy sources get cheaper.
• Subsidies for fossil fuels far outweigh those for renewables. The global bill for fossil fuel subsidies was about $490 billion in 2014, compared with the $112 billion for renewable technologies in the power sector the same year (and another $23 billion for biofuels). But fossil fuel subsidies would have been $610 billion without reforms enacted since 2009.