As economies in emerging markets such as Asia and Africa continue to grow, demand for energy will likewise increase. At the same time, technological advances mean that the ability to produce energy is growing ever faster, whether in unconventional oil and gas, or in renewables like wind and solar energy.

The world is moving towards greater diversity of energy sources—which is good news for the possibility of satisfying growing demand at reasonable cost—but those same forces will make the global energy market that much more complex and competitive.

In fact, by 2040, global energy needs will be satisfied on a roughly equal basis among four energy sources, with coal, oil, gas, and non-fossil fuels–such as nuclear energy and renewables like solar and wind–each supplying 25 percent of global needs.

These were some of the takeaways from a presentation of the 2018 BP Energy Outlook by Spencer Dale, the company’s chief economist, at a gathering sponsored by Columbia University’s Center for Global Energy Policy yesterday in New York.

The diversity of energy supply is being driven by renewables, which will account for 40 percent of the increase in primary energy by 2040 and its rate of growth increasing from four percent today to 14 percent per year by 2040. Energy demand is projected to increase by one-third during that same period. All of this, said Dale, “is leading to the most diversified fuel mix ever seen.”

Demand for oil and other conventional fuel will also grow through 2040 as well, but demand for those “gradually slows and plateaus in the…years” approaching 2040.

Natural gas, which is projected to grow at an average of 1.6 percent per year will grows much faster than either oil or coal. Gas will overtake coal and will approach the demand for oil as 2040 approaches. Natural gas plus renewables will account for 75 percent of global growth through 2040.

Oil demand is projected to grow at an average rate of 0.5 percent per year over much of the outlook period, before it plateaus during the later years of the projection. Coal consumption is relatively flat through 2040, but its share in primary energy will decline to 21 percent, its lowest share, according to Dale, since the industrial revolution.

Abundant and diversified energy supplies is perhaps well suited to satisfy growing global energy demand, but it “will make for a challenging marketplace,” said Dale. “Don’t be fooled by the recent firming in oil prices. The focus on efficiency, reliability and capital discipline is here to stay.”