Why Methane Is Climate’s Low-Hanging Invisible Fruit
(Bloomberg) -- Methane is the second-largest contributor to global warming after carbon dioxide. But new and better techniques to spot major emitters of the odorless, colorless gas have pushed curbing it up climate to-do lists. Scientists view reducing methane emissions from the fossil fuel industry as the cheapest and easiest way to hold down global temperatures in the near term. That could blunt the worst of climate change while buying time for reducing carbon emissions.
1. What is methane?
It’s an invisible, odorless gas that, like carbon dioxide, traps solar energy as it’s radiated back toward space from the Earth’s surface. Unlike carbon dioxide, which can contribute to heating for centuries or longer, the impact of methane, whose chemical name is CH4, is felt primarily in the first 20 years after its release. During this period its potency can be more than 80 times that of CO2.
2. Where do methane emissions come from?
Human activity accounts for about 60% of global methane emissions annually, with about 35% of that attributable to the fossil fuel industry. Methane is the primary component of natural gas, and leaks can happen anywhere along the natural gas supply chain, from the wellhead to the homes and businesses where the fuel is burned. But the gas can also be released during oil and coal production. Landfills, burping cows, rice paddies, and manure are also major sources that humans are responsible for. (Cows aren’t manmade, but the vastness of their herds is.) Naturally occurring methane seeps from fissures in the Earth’s surface, mud volcanoes and wetlands.
3. Why the focus on fossil fuels?
Leaks from energy infrastructure are the easiest and cheapest sources of methane to identify and fix. There’s also an economic incentive: Producers can make up for the cost of repairs by selling the extra gas they capture. There are also efforts to create a natural gas standard that would certify emissions associated with production and transport. As much as 80% of measures to curb methane from oil and gas operations, and up to 98% from the coal sector, can be implemented at no cost or at a savings, according to the United Nations’ 2021 global methane assessment. Officials also hope to cut down on the venting (releasing) of natural gas that often happens when there’s no available pipeline capacity or when producers are only interested in capturing the oil from a well. Some of that gas is flared (burned) to convert the methane into carbon dioxide, but environmentalists and some investors have pushed for limits on flaring because not all the methane is combusted in the process. Instead, excess gas could be reinjected into the ground.
4. How are leaks found?
For decades, producers and regulators relied on crude techniques like throwing a tarp over a pipe to see if it bubbled or sending workers out to inspect equipment. Leak detection is entering the digital age, with satellites used to spot the biggest sources of methane while drones, aircraft and ground-based monitors find smaller points of emission.
5. What are governments doing?
The U.S. Pipes Act, passed in December 2020, directs oil and gas operators to use advanced leak detection technologies and adopt steps to reduce releases during maintenance. President Joe Biden is rolling back efforts by his predecessor, Donald Trump, to loosen regulations on drillers and pipelines. It’s not just the U.S.: China’s latest Five-Year Plan was the first to mention tightening control over methane. The International Methane Emissions Observatory, a collaboration of the UN and the European Union, plans to create a public database of verified methane emissions to better understand patterns of emissions, in part by using observations from space. More satellites including from the Environmental Defense Fund and a consortium including Carbon Mapper, the State of California and Planet Labs Inc. are scheduled to launch over the next few years.
6. What impact can this have?
Methane emissions generated from human activity could be cut by 45% by 2030 with readily available technology, a step that could avoid nearly 0.3 degrees Celsius (0.5 degrees Fahrenheit) of warming by the 2040s, according to the UN assessment.
7. What are the hurdles?
Methane emissions from livestock and agriculture pose more challenging problems that require changes in how farmers raise crops and feed livestock — not to mention behavioral adjustments by consumers fond of their hamburgers. Mass adoption of plant-based alternatives and lab-grown meat could help. In the oil and gas sector, laws and policies to curb methane emissions vary widely across large producers like the U.S., Russia and Saudi Arabia, and a rebound in oil prices could revive drilling by the producers who are most willing to skimp on equipment, even if it pays for itself in the long run.
The Reference Shelf
- The United Nations’ global methane assessment for 2021.
- The Global Methane Initiative’s website offers data and a factsheet on the gas.
- A Bloomberg Green overview of the tech being used to track down methane leaks, and a feature on a methane map powered by satellites.
- A report on the implications of satellite-based methane detection for policy, industry and finance from Columbia University’s Center on Global Energy Policy.
- The European Commission’s strategy for reducing methane emissions.
- A report about methane emissions from natural gas and LNG imports into Europe from the Oxford Institute for Energy Studies.
- An analysis of methane emissions over the U.S. Permian Basin from the Environmental Defense Fund.
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