Through its Climate Action Plan and other efforts, the Obama Administration is paying special attention to reducing methane emissions these days. It first laid out a set of actions in its “Strategy to Reduce Methane Emissions” in March 2014 with a focus on the agricultural sector and coal mines. A few weeks ago, the Administration announced a new plan to cut 40% of emissions from the oil and natural gas sector over the coming decade. That’s good news for people’s pocketbooks and safety and for the environment, as well. The key will be to do it as efficiently and inexpensively as possible.
Why the focus on methane? Methane accounts for about one tenth of total U.S. greenhouse gas emissions. Molecule for molecule, it’s a far stronger greenhouse gas than carbon dioxide, and it can contribute to local air pollution problems such as ozone and smog formation. Without the proposed plan, methane emissions were projected to grow by one quarter over the next decade because of strong growth in the oil and gas industry in the U.S.
The government’s plan has several components. One piece focuses “upstream” at wellpads and processing and compressor stations. It will reduce gases lost from pneumatic pumps, valves, tanks and other equipment that you see when you drive by an oil and gas operation. Other pieces focus “midstream” on pipelines that move natural gas across the country and “downstream”, in the distribution networks that serve our cities and homes.
One of the surprising conclusions from recent measurements is that state and federal governments sometimes underestimate methane emissions. A few weeks ago our team, including scientists from Harvard, Duke, Boston University, and Stanford, published new results in a PNAS paper on Methane Emissions from Natural Gas Infrastructure and Use in the Urban Region of Boston, Massachusetts. Using rooftop measurements we found that methane emissions to Boston’s air were two or three times higher than what the Massachusetts greenhouse gas inventory suggested they should be. We identified several possible reasons for the discrepancy, including:
- Not all emission sources are counted – U.S. and Massachusetts inventories often don’t include natural gas losses in buildings and homes, such as from furnaces, and emissions from industrial facilities can be missed;
- Surveys on the ground can miss emissions from places that are hard to access or emissions that are temporary but large.
- Pipeline leaks may be higher than the state thinks; Boston has older pipelines than average for the U.S. but its pipelines are a lot like those in other cities such as Philadelphia, Baltimore, Washington D.C., and New York City.
In fact pipeline repair is one area that’s ripe for continuing progress. Pipeline safety has improved substantially over the last decade. Nonetheless, companies need to be able to spend more on pipeline replacement and repairs than they currently do. Many people don’t know that their local Public Utility Commission controls how much companies can typically spend for repairs. Many people also don’t know that ratepayers, people like you and me, typically pay for the natural gas that leaks from company pipelines. One obvious solution, then, is to allow companies to recover more costs temporarily to repair pipelines, while at the same time weaning them from being paid for natural gas that they lose.
Successful pipeline replacement programs have already worked. Duke Energy of Ohio began its replacement program in 2001. At that time, some of its natural gas pipes dated back to the 1880s. Duke Energy’s fifteen-year program has now replaced more than a thousand miles – 90% – of its older cast-iron and unprotected steel pipes at a cost of around $1 billion.
A billion dollars is a lot of money, but we’re losing that much money by not repairing pipes faster, too. The total value of gas emitted in Boston over the year of our study was $90 million. A decade’s worth of losses would total almost $1 billion, too.
Economics, the environment, and safety all point to the benefits of reducing methane emissions, from pipelines and elsewhere. The full environmental benefits of using natural gas to replace other fossil fuels will only be fully realized through active measures to decrease leakage. The President’s Climate Action Plan presents a great opportunity to do just that, so long as creative partnerships among companies, utility commissions, consumers, and cities and states provide the foundation.