Burning fossil fuels to generate electricity is the largest single source of greenhouse gas emissions in the United States, accounting for 31 percent of total greenhouse gas emissions in 2013. On Monday, President Obama is taking a big step toward regulating those emissions with the release of the final Clean Power Plan rule, the first rule designed to regulate carbon pollution from existing power plants. If the rule holds up to legal challenges, encourages international action from other major economies, and survives the next presidency, it would help to stabilize greenhouse gas emissions and stave off the worst of global warming.
But what about the other 69 percent of greenhouse gas emissions that the CPP doesn’t cover? As Slate’s Eric Holthaus points out, necessary emissions reductions might call for something like an 80 percent reduction by 2030 — far higher than the 6 percent reduction that Vox’s Brad Plumer calculates would be achieved if the finalized CPP was carried out in full.
“There are lots of other really important emissions sources that the administration should be addressing,” Kristin Meek, an associate with the World Resource Institute’s climate team, told ThinkProgress. But the good news, Meek adds, is that the administration is already starting to tackle these emission sources. “The recent action, especially over the last six months, shows they are beginning to address this,” she said.
So what are the other major sources of greenhouse gas emissions in the country — and what is being done to reduce their contribution to climate change?
Part of the CPP’s appeal is that it will force the transition from coal — an extremely dirty source of power — to cleaner alternatives. But environmentalists worry that it could simply encourage states to move from coal to natural gas — an energy source that still comes with environmental downsides. Natural gas is cleaner than coal — studies have shown that is releases half as much carbon dioxide when burned as coal, but it’s not without its issues. Natural gas production can leak methane, a greenhouse gas 84 times more potent than carbon dioxide over a 20 year period. If natural gas production isn’t tightly controlled, methane leaks could ostensibly detract from its environmental benefits, which is why environmentalists argue that any meaningful natural gas push meant to curb greenhouse gas emissions should include some kind of methane-reduction strategy. In January, the EPA announced plans to reduce methane emissions from the oil and gas sector 40 to 45 percent by 2025 compared to 2012 levels. But those regulations only cover new oil and gas constructions — not existing ones.
“We need a regulatory approach to get at existing methane pollution,” Alison Cassady, Director of Domestic Energy Policy at the Center for American Progress told ThinkProgress. “We need to make sure every oil and gas well and pipeline is releasing as little methane as possible.”
Besides the power sector, the transportation sector is the second-highest source of greenhouse gas emissions in the United States. That includes things like highway vehicles, airplanes, marine transport — anything that relies on the combustion of fossil fuel to transport people and goods, according to the EPA. In 2013, transportation was responsible for 26 percent of total U.S. greenhouse gas emissions.
“Transportation is also a big source of emissions,” Meeks said. “But this is one area that the administration has really been proactive on.”
Sixty-two percent of transportation-related emissions come from light-duty vehicles, like passenger vehicles. In 2012, the Obama administration finalized Corporate Average Fuel Economy (CAFE) standards that raised fuel efficiency standards to 54.5 miles per gallon by 2025, calling the new standards “historic.” In the year after the CAFE standards were set, the fuel economy of vehicles sold in the United States increased by 1.4 miles per gallon. Since then, cars have become increasingly more fuel efficient, exceeding emission standards by a “wide margin,” according to the EPA.
But in order to really make a dent in U.S.-related greenhouse gases, light-duty vehicles will need to become even more fuel efficient. In June, the World Resources Institute looked at how the United States could achieve meaningful emissions reductions without Congress — and one of the key takeaways is that light-duty vehicles will need to quickly become more fuel efficient, through deployment of next-generation technologies like battery and fuel cells. WRI also argues that the EPA and the DOT should set a 63 mile-per-gallon CAFE standard by 2030, which would encourage innovation in the manufacturing sector and spur state and federal governments to expand infrastructure for alternative vehicles.
Cassady agrees that encouraging the transition to clean vehicles will be crucial for cutting emissions in the transportation sector.
“One opportunity that the country has is to expand opportunities for electric vehicles,” she said. “Right now, they just aren’t broadly deployed, but as our power sector gets even cleaner the advantage of using electric vehicles will be even greater.”
Earlier this summer, the Obama administration also began taking steps to regulate emissions from airplanes and medium- and heavy-duty trucks. On June 10, the EPA announced that emissions from airplanes constitute a health hazard due to their contribution to global warming, and argued that they should be regulated under the Clean Air Act. In the United States, aircraft emissions account for eight percent of the greenhouse gas emissions associated with transportation. The agency has yet to issue a rule on airline emissions, however, saying that they’re waiting for international negotiations on carbon emissions in the aviation industry to wrap up in February of 2016. Aviation emissions only account for two percent of global greenhouse gas emissions, though it’s one of the fastest-growing sources, and could increase by 70 percent over 2005 levels by 2020, according to the New York Times.
Medium- and heavy-duty trucks are the second-largest source of greenhouse gas emissions within the transportation sector. In June, the EPA and the Department of Transportation released fuel efficiency standards for heavy-duty trucks, calling for a 24 percent reduction in CO2 emissions and fuel consumption from semi-trucks, large pickup trucks and vans, buses, and work trucks released between 2021 and 2027, compared to 2018 models.
Industry is another large contributor to United States’ total greenhouse gas emissions, accounting for about 12 percent of the country’s total in 2013. According to the WRI, barriers like remaining financially competitive, regulation, and lack of information combine to hinder industry’s ability to quickly adapt to new energy-efficient technologies. To combat these barriers, the WRI proposes expanding federal programs like the president’s Better Buildings Challenge, which could help commercial and industrial buildings become 20 percent more energy efficient by 2020. Expanding renewable energy could also benefit industry, which could use clean options like distributed wind or solar to help reduce their greenhouse gas emissions.
“It’s tricky because there are so many different sub-sectors: pulp and paper, cement, refineries,” Meek said. “They’re all very different, so coming up with smart, flexible standards for each of these different sub-sectors will take time.”
Beyond industry, agriculture is another large source of greenhouse gas emissions in the United States. In 2013, the agricultural sector accounted for 7.7 percent of greenhouse gas emissions in the country, primarily by releasing methane, through livestock production, and nitrous oxide, through fertilizer runoff. In April, the United States Department of Agriculture announced a set of initiatives to help farmers, ranchers, and forest land owners mitigate their contribution to climate change. The measures are all voluntary, though the USDA hopes to incentivize participation by offering grants, low-interest loans, and technical assistance.
The most comprehensive solution to carbon pollution would be to put a price on carbon, in the form of a carbon tax or through a cap-and-trade approach, which would help drive down carbon pollution across all these sectors, Cassady said. But the administration’s attempts to pass a cap-and-trade bill died in the Senate in 2009 — since then, the Obama administration has taken a more piecemeal approach to climate policy, using the executive branch’s authority under the Clean Air Act to drive down emissions bit by bit across a number of sectors.
The Clean Power Plan is a huge part of that approach, and one that Obama reportedly sees as central to his legacy. But the CPP could do more than cut carbon pollution from the power sector — it could give the United States a strong bargaining chip heading into the U.N. Climate Conference in Paris.
“By taking bold action, the U.S. will have leverage,” Cassady said. “We are leading by example, so when we go into the Paris climate negotiations, we can point to the CPP and the cuts we are willing to make to spur action by other countries.”