While the U.S. has relied on cheap natural gas to help fuel the power grid, overseas consumers are increasingly relying on cheaper alternative energy sources, which could help support exchange traded funds that track global coal and clean energy industries.

“Slower economic growth, the ever-strong competition from both coal and renewable energies, together with high gas prices, are all slowing down the growth of natural gas across all sectors,” the International Energy Agency said, Bloomberg reports. “The maturity of most markets, slower economic growth, and competition from renewable energies or coal” will diminish developed nations’ demand.

According to the IEA, global coal demand rose 3% to 4% while renewable power generation grew over 4% last year.

Europe has switched to alternative energy and coal at the expense of natural gas on expanding green power generation and lower coal prices. The IEA predicts that renewables will climb to  260 terawatt-hours in OECD Europe by 2019.

“In particular, generation from wind continues to increase strongly,” the IEA said. “Against this backdrop, renewable energies generate more additional power than the additional generation needed. If not for a declining nuclear output, combustible fuels (gas, coal and oil) would face an absolute decline, but the drop in nuclear actually compensates for the surplus of renewable sources.”