Could "clean coal" meet the energy needs of the United States for the next 1,000 years, as Republican presidential nominee Donald Trump said on Sunday (Oct. 9) during the second presidential debate?
Scientists contacted by Live Science are dubious both about whether current U.S. supplies of this fossil fuel could last more than a century and whether the country will start implementing industrywide practices to meet the clean coal definition.
As of now, there aren't any operational U.S. coal plants that use so-called clean coal technology, said Edward Rubin, a professor of engineering, public policy and mechanical engineering at Carnegie Mellon University in Pittsburgh.
Moreover, if the United States continues to use coal at its current rate of consumption, the known coal deposits will last only about 100 more years, according to a 2007 report from The National Academy of Sciences, a nongovernmental, nonprofit group chartered by the U.S. Congress at the request of President Abraham Lincoln. [Election Day 2016: A Guide to the When, Why, What and How]
Trump's comment came about during a town-hall debate, held at Washington University in St. Louis. The newly minted internet star Ken Bone — the man with the bright-red sweater and black-rimmed glasses — asked both candidates, "What steps will your energy policy take to meet our energy needs, while at the same time remaining environmentally friendly and minimizing job loss for fossil power plant workers?"
During his 2-minute response, Trump said, "There is a thing called clean coal. Coal will last for 1,000 years in this country."
What is clean coal
The Department of Energy (DOE) coined the term "clean coal" in the 1980s when it created a program with the same name that was devoted to advancing environmental technologies to remove regulated air pollutants from the emissions of coal-powered plants, Rubin said.
"The DOE program was created to develop better or less expensive technology for controlling the major pollutants related to acid rain: sulfur dioxide and nitrogen oxide," Rubin told Live Science. Previous regulations had already addressed coal's particulate matter, including dust and soot, he noted.
In 2009, the Environmental Protection Agency (EPA) classified the greenhouse gas carbon dioxide (CO2) as a pollutant that could endanger health and lead to climate change and ocean acidification, according to the EPA.
In general, clean coal refers to removing any regulated pollutant emitted from burning coal, but nowadays, the focus is on CO2, Rubin said. This effort is called carbon capture and storage, or CCS.
The technology for capturing CO2 already exists in the industry (sectors that actually transform raw materials into energy or products), but not in the electrical power sector, which has larger facilities than industry typically does, he said. What's more, this sector doesn't employ as many chemical engineers, who often implement carbon capture, as the industry does, Rubin said.
Compressing CO2 and turning it into a "supercritical fluid," Rubin said, can carry out the storage part of CCS. Then, it can be transported through pipelines to a destination — an underground geologic formation, for example.
However, implementing CCS costs money, and there's little impetus for power plants to use it unless they are required to do so by the government, Rubin said. [Science of Politics: Why Trump and Clinton Should Be Nice to Each Other]
"From everything I've read about Mr. Trump's view of climate change, I suspect he would not be a proponent of policies to reduce carbon emissions drastically, although that would be a good question to ask him," Rubin said.
A look ahead
There are two CCS plants in the country that are under development: the Kemper Project in Mississippi and the Petra Nova Project in Texas, but neither is open yet, Rubin said. (The National Energy Technology Laboratory website has a list of CCS projects through 2015.) But despite these two projects, clean coal does not appear to be spreading to the hundreds of other working coal plants in the country.
Mary Finley-Brook, an associate professor of geography, environmental studies and international studies at the University of Richmond in Virginia, laid it out in an email to Live Science.
"Clean coal does not currently exist," Finley-Brook wrote in an email. "It will be expensive to develop and is uncertain (unlikely) to work, depending on what technology is selected. This is moving in the wrong direction from a climate change mitigation perspective. We need energy transition away from fossil fuels, not nice-sounding names to confuse people who don't know better."
Pushker Kharecha, a climate scientist at The Earth Institute at Columbia University, added that even if clean coal were developed, it might create a sense of complacency when addressing climate change.
"In my opinion, the top priority of emission-reduction efforts should instead be switching to non-fossil energy sources (renewables and nuclear) by as much as possible and as quickly as possible," Kharecha told Live Science in an email.
Trump's "1,000 years" statement is off by an order of magnitude, Rubin said. In reality, the estimate is about one-tenth of that.
"There is probably sufficient coal to meet the nation's needs for more than 100 years at current production levels," but for less than 250 years, according to the 2007 report.
However, with natural gas use spiking, there is less demand for coal. In 2008, coal supplied about 50 percent of electricity to the United States, but it was just 33 percent in 2015, Kharecha said. [What Are the Most Dangerous Jobs]
Democratic presidential nominee former Secretary of State Hillary Clinton may have also made an erroneous statement regarding energy, when she said that the United States is "now, for the first time ever, energy independent." But that's not the case, as the United States imports about 9.4 million barrels of petroleum [a fossil fuel made from crude oil and natural gas] a day, mostly from Canada, according to NPR.
Original article on Live Science.