The U.S. Environmental Protection Agency (EPA) issued a long-awaited revised proposal for Clean Air Act standards to curb carbon pollution from new power plants. The rule sets separate standards for new gas-fired and coal-fired plants. It would require future coal-fired plants to limit emissions of carbon dioxide to 1,100 pounds per megawatt hour (MWh). The average U.S. coal-fired plant currently emits nearly 1,800 pounds per MWh. Large combined cycle natural gas plants producing at least 850 megawatts of electricity would be limited to 1,000 pounds per MWh, while smaller plants could emit up to 1,100 pounds per MWh. The new proposal replaces an earlier standard issued in 2012 that would have required all types of facilities to limit emissions to 1,000 pounds per MWh (subscription).
“We have proven time after time that setting fair Clean Air Act standards to protect public health does not cause the sky to fall,” EPA Administrator Gina McCarthy said. She went on to say that the proposal, “rather than killing future coal, actually sets out a certain pathway forward for coal to continue to be part of a diverse mix in this country.”
New coal plants would likely need to implement carbon capture and sequestration (CCS) technology, under the rule set to be finalized next year. That rule will trigger the drafting of standards for existing sources under section 111(d) of the Clean Air Act. Much of the opposition surrounding the rule, which is set for proposal in June 2014, is likely aimed at limits for these existing coal and natural-gas fired plants, which vary in age. There may be one significant difference between the new source and existing source rules, the Washington Post reports. Carbon capture and sequestration may not be part of existing source rules.
In preparation for the proposal to cut carbon from existing sources, public comment sessions will begin around the country this fall. Although the EPA would create and enforce the rules directly, states would determine how to meet limits.
Studies Look at Arctic Ice, Drilling
Ahead of the U.S. Department of Interior’s release of minimum standards for oil and gas exploration in federal waters off Alaska’s Arctic coast, Pew Charitable Trusts has put out a 142-page document offering suggestions for how these guidelines might look. The study covers roughly 80 recommendations that include everything from the length of the drilling season to equipment durability and emergency spill protocol.
“We are recommending both exploration and production drilling restrictions and operational restrictions during certain hazardous Artic conditions,” said Marilyn Heiman, director of Pew’s U.S. Arctic Program. “Our report is clear: If you can’t clean up a spill in Arctic conditions, then we recommend that drilling operations be limited to periods of time when you can clean up a spill.”
Arctic sea ice experienced record melts that opened shipping lanes for offshore drilling in 2012, but it appears to be making a comeback, according to the New York Times. That doesn’t necessarily mean the ice is recovering—measurements taken September 13 were still the sixth-lowest on record.
Higher Risk of Storms Forecast
Research in the journal Proceedings of the National Academy of Sciences suggests the eastern and central United States faces a higher risk of severe weather as global warming causes an increase in the conditions producing thunderstorms. By the middle of the century, the eastern U.S. could see severe storms an average of 7.5 spring days, with the largest increase to 2.4 days from March through May across portions of Texas, Oklahoma and Louisiana.
“We’re seeing that global warming produces more days with high CAPE [convective available potential energy] and sufficient shear to form severe thunderstorms,” said Noah Diffenbaugh, study co-author and associate professor of environmental Earth system science at Stanford. This pattern, revealed by the research team’s computer modeling, may have been missed in previous work. Earlier studies concluded that although global warming increases CAPE, it decreases wind shear, and the two phenomena cancel each other out.
The Climate Post offers a rundown of the week in climate and energy news. It is produced each Thursday by Duke University’s Nicholas Institute for Environmental Policy Solutions.