Methane gets its due: Climate pledge puts focus on super pollutants
| PASADENA, CALIF.
Environmentalists are cheering a new focus on super pollutants – which, as a group, account for about 40% of global warming. Control more of these substances such as soot and refrigerants, say climate scientists, and you will get quick results – buying time while the world works to reduce carbon dioxide emissions.
Scientists have been raising the alarm about super pollutants for years. This year, international leaders finally responded to experts’ cry about a key one: methane. In Glasgow, Scotland, this week, more than 100 countries – though not China or Russia – pledged to cut methane emissions by at least 30% from 2020 levels by 2030. The pledge covers nearly half of global methane emissions.
Why We Wrote This
Gases like methane are called super pollutants because they are such potent trappers of heat in Earth’s atmosphere. Yet that also means cutting their emissions can be a potent response to global warming.
In the U.S., the Biden administration also proposed new regulations to cut methane emissions in the oil and gas sector. And individual states have committed to attacking super pollutants through the U.S. Climate Alliance.
The reduction of super pollutants faces myriad impediments. But energy professor Daniel Kammen at the University of California, Berkeley is heartened by the methane pledge. It’s a “really impressive shot,” he says.
At last, methane is getting global attention as a greenhouse gas, say environmentalists. They are cheering the pledge to reduce methane emissions signed by more than 100 countries at the COP26 climate summit in Glasgow, Scotland.
Methane (CH4) is the No. 2 Earth-warming gas behind carbon dioxide, but it is far more potent than CO2. Methane belongs to a group of short-lived, heat-trapping gases known as super pollutants that have a supersized impact on global warming in the near term.
Control these, say climate scientists, and you will get quick results – and buy time while the world continues to grapple with reducing carbon dioxide emissions.
Why We Wrote This
Gases like methane are called super pollutants because they are such potent trappers of heat in Earth’s atmosphere. Yet that also means cutting their emissions can be a potent response to global warming.
What are super pollutants?
As a group, they account for about 40% of global warming, according to a recent report by The Climate Center, which is based in California – a leading state in tackling super pollutants. Big players in the group include methane (from oil and gas leaks, agriculture, and organic waste in landfills); black carbon, commonly called soot (from diesel engines, burning wood, and other sources); and hydrofluorocarbons, or HFCs, which are coolants for refrigeration and air conditioning.
Super pollutants also are ultra heat trapping compared to carbon dioxide. Black carbon and HFCs are about 2,000 times more potent, and methane is more than 80 times more potent over a 20-year period. This group can stay in the atmosphere from days to decades, compared to carbon dioxide and other long-lived climate pollutants, which can stick around for centuries.
“Just focusing on CO2 is not enough,” says Daniel Kammen, one of the co-authors of the report and a professor of energy at the University of California, Berkeley.
Why are super pollutants so important?
It’s that combination of potency, their relatively short life, and their big percentage in the greenhouse gas mix that makes them such a high-value target. That, plus the fact that technology readily exists to curtail these pollutants. It’s all about speed. Fast cuts to this group would cut in half the rate of global warming by 2050, says climate scientist Veerabhadran Ramanathan, at the Scripps Institution of Oceanography at the University of California, San Diego.
Global warming is “going to get progressively worse over the next 10 years. But [the rate] would stabilize and come down if we deal with the super pollutants,” Dr. Ramanathan told the Monitor in an interview earlier this year.
What is being done to cut super pollutants?
Scientists have been raising the alarm about super pollutants for years. This year, international leaders finally responded to experts’ cry about methane. After President Joe Biden and European Commission President Ursula von der Leyen did a “soft rollout” of a pledge to cut methane in September, they took it to Glasgow this week. More than 100 countries – though not China or Russia – pledged to cut methane emissions by at least 30% from 2020 levels by 2030. The pledge covers nearly half of global methane emissions.
At the same time, the Biden administration proposed new regulations to cut methane emissions in the oil and gas sector – first introduced by President Barack Obama, then rolled back by President Donald Trump, and now fortified under Mr. Biden. For the first time, the proposed rule would target existing oil and gas wells nationwide (not just new ones), requiring regular monitoring and control of methane leaks. Technology exists to readily detect and fix such leaks. The White House maintains the proposal would reduce U.S. methane from this key sector by 75% by 2030 compared with 2005.
The pledge “means a U-turn in methane emissions,” says Katie Ross, a senior associate with the World Resources Institute in its global climate program. “They’ve been rising. Last year was the highest concentration of methane in the atmosphere ever.”
Ms. Ross lists other efforts to curb super pollutants: A legally binding international agreement gradually phases out HFCs, and members of the Arctic Council are on track to meet their aspirational goal and reduce black carbon emissions by 25%-33% by 2025 compared with 2013. Soot is particularly important to Arctic and mountainous regions because it falls on snow and ice, reducing their ability to reflect light.
In the U.S., individual states have committed to attacking super pollutants through the U.S. Climate Alliance, including California, which in 2016 passed a law establishing reduction targets. This January, for instance, all California residents and businesses will be required to recycle food waste – a big source of methane.
Ask Dr. Kammen about impediments to reducing super pollutants and he asks, “how many days do I have” to answer? Pledges need to be turned into timely actions, and then there are legal battles, and the possibility of a future administration reversing course. But he’s heartened by the methane pledge.
It’s a “really impressive shot” he says, benefitting not only the atmosphere but also disadvantaged communities that live near oil and gas wells. As scientists have repeatedly said, it comes in a crucial decade and targets a specific, high-impact gas – making this strategy the most effective one for reducing global warming in the near term.
