When oceanographer Tessa Hill was asked to join the Climate Crisis Advisory Group (CCAG) as an advisor, she was surprised by the reason. The global group, formed in 2021 with the vision of acting as a bridge between the latest climate science and policymakers, was interested in Hill’s background expertise in methane, a potent greenhouse gas.
“I sort of chuckled at that because my research program hasn’t worked on methane in 20 years,” said Hill, whose current research primarily focuses on mitigating the detrimental effects of carbon dioxide on the environment. “But 25 years ago, my whole research program was about methane.”
As a graduate student at UC Santa Barbara, Hill, who is now a professor of earth and planetary sciences at UC Davis, studied natural sources of methane and how those stores changed over time. The breakdown of organic matter in wetlands, melting permafrost in the Arctic and deep ocean sediments are just a few of the planet’s natural sources of methane emissions.
Those natural sources account for about 40% of total methane emissions. The other 60% is anthropogenic.
“When we think about the global methane budget, it actually is dominated by human-caused methane sources,” Hill said.
Why methane is a powerful driver of climate change
While not nearly as prevalent or long-lived in the atmosphere as carbon dioxide, increasing methane emissions are a problem for the environment. For one, the molecule packs a punch. Responsible for about one-third of the Earth’s warming, methane is about 80 times more powerful in terms of global heating than carbon dioxide.
“Another interesting thing is that it degrades in the atmosphere really fast, but it breaks down into carbon dioxide,” Hill said. “So over time, it actually adds to our carbon dioxide burden in the atmosphere.”
In a recent report published by the CCAG, Hill and colleagues advocate for pulling the emergency brake on human-caused methane emissions. They report that if emissions are reduced by 45% this decade, the Earth could avoid 0.3 degrees Celsius of warming.
That might not seem like a lot, but as the report states, “0.3 degrees Celsius could be the difference between adaptation and collapse for millions.”
“Every single thing that we can do to reduce greenhouse gas emissions, and capture and store carbon, if it reduces one-tenth of a degree, or two-tenths or three-tenths, we need it,” Hill said.
Energy, agriculture and waste: the biggest sources of methane
The CCAG report includes practical recommendations for industry and policymakers on how to reach this methane reduction goal. It focuses on three sectors ripe for change: energy (responsible for 40% of human-caused methane emissions), agriculture (also responsible for 40%) and waste (responsible for 20%).
Some of the CCAG’s recommendations for the energy and agriculture sectors include mandating regular leak detection and repair for oil and gas operations, and encouraging alternative agricultural practices that reduce methane emissions, such as feeding adjustments (which CCAG reports can reduce ruminant methane emissions by 60%), and improving methane capture from livestock and manure sources.
Hill said that conversations about climate change are often framed around the idea of sacrifice, specifically when it comes to agriculture. But really, the conversation should be framed around sustainable innovation.
“We’ve learned ways to do things better,” she said. “There’s innovation that’s guiding the way towards more sustainable agriculture that will produce less methane.”
How scientists are tracking methane emissions more accurately
Another CCAG recommendation is requiring transparent and independent measurements for tracking methane emissions from industry.
“In the past, it was difficult for scientists and also policymakers to understand exactly how much methane was being emitted from these sources,” Hill said. “But there have been developments that have allowed scientists to start tracking methane via satellite.”
Historically, methane emissions were monitored via a bottom-up approach, relying on industry to track output. The CCAG suggests comparing that data with a top-down data-gathering approach that uses satellites and aircrafts to monitor emissions. Combining both approaches will help create a more accurate picture of methane emissions and the global methane budget.
The European Space Agency and NASA already have instruments that can help track such emissions, including the Earth Surface Mineral Dust Source Investigation instrument on the International Space Station and the TROPOspheric Monitoring Instrument on the Sentinel-5P satellite.
The California Air Resources Board (CARB) also monitors state methane emissions through its California Satellite Methane Project. In November 2025, CARB announced that the project “helped resolve 10 large methane leaks, equivalent to removing about 18,000 cars from California roads for a year.”
The political and policy challenges of reducing methane
According to Hill, the technological and scientific information to curb methane emissions is readily available. The hurdle is implementation.
“Within the United States, it’s very complicated because our political system is being heavily influenced by industries that benefit from us not addressing this,” she said. “What we lack is the ability to move the industry influence to the side and make appropriate decisions.”
With the Trump administration announcing plans to dismantle the federally funded National Center for Atmospheric Research, it’s imperative, now more than ever, that sustainable innovations be further developed and adopted.
“This is a very clear sign that the federal government right now is literally trying to get rid of the people speaking honestly and clearly about the trajectory we’re on,” Hill said. “It is a matter of public safety, and I think lives will be lost because of the removal of that information.”
Recently, the administration also announced further plans to withdraw from international organizations focused on global cooperation, including the Intergovernmental Panel on Climate Change and the U.N. Framework Convention on Climate Change.
“For the U.S., the role of state governments is going to become incredibly important here,” Hill said. “Oregon, Washington and California have a long history of working really closely together on major issues facing the West Coast.”
In 2022, those states, along with British Columbia, signed a statement of cooperation signaling their continued intent to transition to an equitable and prosperous low-carbon, climate-resilient future. The group is known as the Pacific Coast Collaborative.
“I think we will make progress,” said Hill.
However, she noted that on the federal and global front, the U.S. is increasingly withdrawing as a leader in these areas.
How communities and individuals can help cut methane emissions
Oftentimes, issues as big as climate change can feel insurmountable from the individual level. Hill, however, remains adamant that grassroots, and individual, initiatives are just as important as shifting industry. We can all make changes to live in a more sustainable fashion.
And that’s where the waste/landfill sector comes in.
“This is my favorite sector and the reason why I feel that way is because I do a lot of public
speaking about climate change and people are always asking, ‘What can we do locally?’” Hill said.
According to CCAG’s report, methane emissions from landfill could increase by 70% by 2050 if left unchecked.
“Almost half of municipal solid waste is organic material that could be put to better use,” the report states. “Meanwhile, one-third of all food waste produced globally is lost or wasted — a squandered resource, that once dumped in landfill, becomes a major driver of methane.”
This methane is a natural product of bacteria feeding on organic matter in landfills.
“Quite simply, if we can stop putting organic waste into landfills, we can actually reduce this sector quite a bit,” Hill said. “This is a community decision. It’s about making composting available to people individually, but it’s even better if municipalities implement composting programs.”
A 2023 survey conducted by BioCycle found that some 710 communities nationwide have access to food waste collection programs. That accounts for only 12% of U.S. households. Widespread adoption of such programs by municipalities could put a huge dent in human methane emissions.
“Of course, the other thing that landfills can do is actually capture those methane emissions and then use them for industrial purposes,” Hill said.
Why reducing methane now can make a global difference
The CCAG report notes that biogas digesters can convert such organic material into energy for cooking, transport or electricity.
Implementing similar food waste programs for restaurants would also be a boon for reaching methane reduction goals. Additionally, that wasted food could help manage the hunger crisis.
According to the nonprofit Move For Hunger, about 11.4 million tons of food is wasted in the U.S. restaurant industry each year.
“We have so much food that could be used to feed people and instead it ends up in the garbage,” Hill said. “Let’s reduce food waste and when there is food that needs to be thrown away, let’s get it in the compost rather than the landfill.”
“This is something that we can actually do in our everyday lives and in our communities,” she added.
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