Those who believe the world economy can be sustained with a quick switch to renewable energy sources are engaged in pipe dreams. Ditto for those who believe the world is quickly running out of fossil fuels — or for those who actually believed President Obama’s State of the Union speech pledge to make America more energy independent. "Pipe dreams” is an apt term because the fossil fuel commodity with the most promising future is moved chiefly by pipeline. It’s natural gas. Jim Mulva, chief executive officer of ConocoPhillips, used the term "pipe dreams” in a remarkable speech last week at an energy conference in Houston. He also used the term "hydrocarbon deniers.” This is apt in light of the derision of climate change skeptics. They’re called "global warming deniers.” Mulva isn’t out to debunk global warming. In fact, he believes U.S. energy policy should be coordinated with environmental policy, meshing economic realities with the encouragement of cleaner fuels. One economic reality is that world population will rise 35 percent to 9.2 billion by 2050. "It will need more energy, not less, despite higher efficiency and conservation,” Mulva said, "And tomorrow’s energy must remain affordable.” Carbon-based fuels, he said, "must keep carrying the load.” But those fuels can be cleaner. Natural gas needs to be increasingly part of an energy mix that includes wind, solar, nuclear, oil and — at least in the short term — coal. Obama made a commitment to nuclear energy as well as opening up offshore tracts for oil and gas exploration. In fact, the administration is delaying the latter well beyond a reasonable standard. Mulva said that of the 2.4 billion acres of mineral properties the federal government holds, only about 3 percent has been leased for energy development. The "hydrocarbon deniers” believe economic growth can continue apace without bringing additional oil and gas to the market. This pipe dream goes against all logic. What the world can do is start using less coal and oil while increasing reliance on natural gas. Ah, but aren’t we running out of gas? That question is the stuff of another pipe dream. The planet’s "conventional” gas reserves of 6,500 trillion cubic feet, Mulva said, are enough to meet our needs for 60 years at current levels of demand. Unconventional deposits, such as those found in shale formations, increase the reserves to more than 38,000 trillion cubic feet. Is that reserve estimate a pipe dream in itself? We think not. As technologies develop, the estimates may actually prove to be low. Regardless, the fossil fuel economy is far from extinct. It’s time to stop denying that fact and fashion policies that would pipe cleaner fuels to consumers rather than Washington piping its dreamy fantasies to the people.