Oil, coal and natural gas have powered the U.S. energy demand for generations. Yet now that the U.N. Climate Change Conference appears to have set a landmark agreement, can clean energy replace carbon-intensive sources going forward?
On Saturday, officials from 195 countries in Paris unveiled what France's Foreign Minister called an 'historic' agreement to curb carbon emissions. The deal—a culmination of 2 weeks of marathon talks—still requires the approval of delegates from around the world. In an interview with CNBC this week, one top U.S. official hailed the talks as a major achievement.
"We recognize fossil fuels will continue to be a part of the portfolio for quite a long time," U.S. Energy Secretary Ernest Moniz told CNBC's "On the Money" in an interview. Moniz, who was in Paris recently for climate talks, said he is seeing progress and a "strong commitment" to reduce carbon emissions.
"Almost every country in the world...declared their targets to cut down on (greenhouse gas) emissions, pretty substantially."
Moniz, who has served as President Barack Obama's energy secretary since May 2013, said the U.S. pledged to cut emissions by "27 percent below 2005 levels by the 2025 deadline. He added that there were "comparable targets from most of the big emitters."
Fossil fuels supply constitutes about 80 percent of the energy Americans consume. Meanwhile, alternative energy sources, including wind and solar power, currently generate about 10 percent.
A former physics professor and director of MIT's Energy Initiative, Moniz thinks those figures are poised to "far exceed" those levels soon.
"Wind energy has gone up by several fold just in the last five to six years," Moniz said, "and now (wind) provides about 4.5 percent of our electricity. You add that with solar, we're talking 5 percent."