On Monday, a U.S. Court of Appeals for the District of Columbia order directed the U.S. Environmental Protection Agency (EPA) to carry out an Obama-era rule that sets methane pollution limits for the oil and gas industry.
Nine of the 11 court judges issued the order upholding a July ruling that found that the Trump administration overstepped its authority under the Clean Air Act when it tried to delay the methane rule.
Implemented in 2016, the rule targets new and modified sources of methane emissions, a potent greenhouse gas with long-term global warming potential thought to be many times that of carbon dioxide. The rule was expected to reduce 510,000 short tons of methane in 2025, the equivalent of reducing 11 million metric tons of carbon dioxide.
After President Donald Trump asked the EPA to review the rule in a March executive order, EPA Administrator Scott Pruitt, in an April letter, stayed the deadline for oil and gas companies to follow the new rule by 90 days. Pruitt later sought to pause the methane rule two years to “look broadly” at regulations and review their impact.
Studies Find Earth Tilting Hard toward Warming Tipping Point
Hope that limiting climate change to less than 2 degrees Celsius (3.6 degrees Fahrenheit) above pre-industrial temperatures—the oft-cited threshold of “dangerous” warming—has been further diminished by recent studies published in the journal Nature Climate Change.
One study co-authored by Thorsten Mauritsen of the Max Planck Institute for Meteorology and Robert Pincus of the University of Colorado at Boulder suggests that human forces have heated the climate for longer than thought—since at least 1750—pushing the so-called “preindustrial” baseline for the planet’s warming backward and reducing the amount of carbon dioxide that we can emit to avoid 2 or more degrees Celsius of warming.
The Mauritsen and Pincus study analyzed past emissions of greenhouse gases and the burning of fossil fuels to show that even if that burning suddenly ceased, Earth would continue to heat up about two more degrees Celsius by 2100.
This view was similar to that of another study led by the University of Washington’s Adrian Raferty. That study calculates the statistical likelihood of various amounts of warming by the year 2100 given three trends that matter most for carbon emissions: global population, countries’ GDP (on a per capita basis), and carbon intensity (the volume of emissions for a given level of economic activity). The research puts median warming at 3.2 degrees Celsius and concludes that there’s a 5 percent chance that the world can hold warming below 2 degrees Celsius this century. The authors say there’s a 90 percent chance that temperatures will increase by 2.0 to 4.9 degrees Celsius.
Raferty’s team built a statistical model covering a range of emissions scenarios, finding that carbon intensity will be the most important factor in future warming despite the expectation that technological advances will cut that intensity by 90 percent this century.
“The big problem with scenarios is that you don’t know how likely they are, and whether they span the full range of possibilities or are just a few examples,” said Raferty. “Scientifically, this type of storytelling approach was not fully satisfying. Our analysis is compatible with previous estimates, but it finds that the most optimistic projections are unlikely to happen. We’re closer to the margin than we think.”
Construction Ends on Twin Nuclear Reactors
South Carolina utilities SCANA’s South Carolina Electric & Gas and Santee Cooper on Monday opted to end construction of the V.C. Summer Nuclear Station’s two reactors. The first reactor at V.C. Summer had been expected to go online in August 2019, with the second following a year later.
“The best-case scenario shows this project would be several years late and 75 percent more than originally planned,” Santee Cooper CEO Lonnie Carter said in a statement announcing the decision. “We simply cannot ask our customers to pay for a project that has become uneconomical. And even though suspending construction is the best option for them, we are disappointed that our contractor has failed to meet its obligations and put Santee Cooper and our customers in this situation.”
The move makes the future of the United States nuclear industry even more unclear. With just one nuclear plant under construction, as much as 90 percent of nuclear power could disappear over the next 30 years if existing units retire at 60 years of operation—the current maximum length of operating licenses.
In the southeast, where the V.C. Summer Nuclear Station reactors were located, it is unlikely that existing units can simultaneously be replaced with new plants given the long lead times and limited applications for new nuclear plants at the Nuclear Regulatory Commission. A Nicholas Institute for Environmental Policy Solutions study explores how the potential loss of existing nuclear plants in the Southeast interacts with the regions other electricity sector challenges—among them, increasing natural gas dependence, demand uncertainty, and emerging technology—and it proposes steps states can take to address these challenges.
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.