This article is from the archive of our partner National Journal

The U.S. natural-gas boom is a big reason why the nation's carbon emissions have dropped by around 10 percent over the past decade.

But don't look for climate crusader Al Gore to cheer the rise of gas, even though gas produces just half the carbon-dioxide emissions of coal.

In an interview with National Journal, Gore explained why he's no fan of natural gas, which has enjoyed support from the Obama administration and has eaten into a big chunk of coal's leading share of U.S. power generation.

He's skeptical of the fuel even if regulators decide to clamp down hard on leaks of methane from natural-gas production and distribution, which he believes EPA should do. Those leaks erode at least a portion—some researchers believe a huge amount—of the climate edge gas holds over coal as a power source.

"[I]t is still a losing game for two reasons: It is still a carbon fuel. [Gas] still contributes to the problem, and the skies are already saturated. They say it is a glass half-full, glass half-empty issue, because, in theory, gas has only 50 percent of the CO2 of coal, two-thirds of that of oil. But the atmosphere is already completely full. That is one reason why I don't think it is the best option," Gore said in an interview with National Journal in New York City on Wednesday.

Gore was in New York for his annual "24 Hours of Reality" broadcast on climate change, which was staged at an overhauled warehouse space called Duggal Greenhouse in Brooklyn's Navy Yard.

Gore argues the future of natural gas "is not what it once seemed." A second big reason, he said, is that renewables, especially solar, are ready to give natural gas a run for its money on cost.

"This solar revolution and wind revolution—but particularly the solar [photovoltaic] revolution—is for real, and the cost declines are continuing. There is no end in sight," Gore said, adding that solar is already at cost parity with conventional energy sources in a number of states and countries.

"It continues to go down year after year after year, and the more of it we use, the cheaper it gets. The more gas, coal, and oil we use, the more expensive they get," Gore said. "So the handwriting is on the wall, and with the advances in cost-effective energy storage, the intermittency problem is going to be solved; the interconnections also help to solve that problem, as do the synergies between wind and solar."

Gore also said there's resistance in other parts of the world to the hydraulic fracturing that's enabling the U.S. natural-gas production boom, and he predicted that U.S. natural-gas exports will raise domestic prices.

"There is an arbitrage waiting to happen. The price of gas in Asia is, what, four times higher than the price in the U.S.? And almost that same differential in Europe. There's a growing fervor in the oil-and-gas states to allow the export of these fuels, and I would bet that, eventually, that will happen. So this arbitrage will raise the price of gas in the U.S., and as the renewable prices continue to go down, these lines are going to cross," Gore said.

On a separate topic, Gore also predicted that U.S. restrictions that largely ban crude-oil exports will crumble. As U.S. crude-oil production surges, powerful segments of the oil industry and some lawmakers are pushing to relax the limits imposed in the 1970s.

While some activists have argued that allowing U.S. exports would worsen emissions, Gore said the crude-export battle is not a priority for him.

"I think it is almost inevitable that the exports will be allowed at some point. We are in a global economy. The rapid change within the industry is doing nothing but building pressure to allow those exports. But that particular issue is not at the top of my priority list," he said.

Expect to see and hear more from Gore in the coming days. He's taking part in a large climate-change march in New York City this Sunday, and two days later will address the United Nations climate summit that President Obama is attending.

A separate story in National Journal Wednesday explored Gore's views on the politics of climate change and the 2016 presidential election.

This article is from the archive of our partner National Journal.

We want to hear what you think about this article. Submit a letter to the editor or write to letters@theatlantic.com.