You can’t manage what you don’t measure. The adage is especially relevant for climate-warming greenhouse gases, which are crucial to manage—and challenging to measure. In recent years, though, satellite and aircraft instruments have begun monitoring carbon dioxide and methane remotely, and NASA’s Carbon Monitoring System (CMS), a $10-million-a-year research line, has helped stitch together observations of sources and sinks into high-resolution models of the planet’s flows of carbon. Now, [the White House] has quietly killed the CMS, Science has learned.
The move jeopardizes plans to verify the national emission cuts agreed to in the Paris climate accords, says Kelly Sims Gallagher, director of Tufts University’s Center for International Environment and Resource Policy in Medford, Massachusetts. “If you cannot measure emissions reductions, you cannot be confident that countries are adhering to the agreement,” she says. Canceling the CMS “is a grave mistake,” she adds….
High levels of methane emissions from the oil and gas industry are responsible for one of the most urgent climate problems we face today. Methane, a byproduct of oil and gas production, is a potent greenhouse gas. Methane is 85 times more potent than CO2 when measured over 20 years and 25 times more potent when measured over 100 years. Alarmingly, methane emissions worldwide are growing at 25 million tons per year, and a recent NASA study points to the fossil fuel industry as producing nearly 70 percent of all new emissions….
“Combining isotopic evidence from ground surface measurements with the newly calculated fire emissions, the team showed that about 17 teragrams per year of the increase is due to fossil fuels, another 12 is from wetlands or rice farming, while fires are decreasing by about 4 teragrams per year. The three numbers combine to 25 teragrams a year — the same as the observed increase.”
› Atmospheric methane concentrations are given by their weight in teragrams.
› One teragram equals about 1.1 million U.S. tons — more than the weight of 200,000 elephants.
› Methane emissions are increasing by about 25 teragrams a year, with total emissions currently around 550 teragrams a year.
Atmospheric methane concentrations continue to increase globally, despite a pledge in 2016 from the leaders of the United States, Canada, and Mexico to reduce methane emissions from each country’s oil and gas sector. Additionally, the trilateral methane pledge faces more challenges as the Trump Administration seeks to reverse federal methane research and control efforts.
….The researchers suggest that estimating emissions consistently across U.S. jurisdictions in support of a robust baseline will help the North American countries to achieve the goal by 2025, if coupled with science-based, economically sound policies to minimize methane leakage.
“It is critical — for both the development of the sector and the environment — that decision-makers in government and industry rely not only on politics and economics, but also scientific evidence,” Dr. Jordaan said. “We have developed a coherent framework that integrates science and policy to help decision-makers to do just that, in support of both economic and environmental goals.”
….Konschnik noted that the climate benefits of using natural gas rather than coal to generate electricity evaporate if methane leakage across the natural gas value chain is too high….
Kate Konschnik, Sarah Marie Jordaan. Reducing fugitive methane emissions from the North American oil and gas sector: a proposed science-policy framework. Climate Policy, 2018; 1 DOI: 10.1080/14693062.2018.1427538
ABSTRACT: The shale gas boom in the United States spurred a shift in electricity generation from coal to natural gas. Natural gas combined cycle units emit half of the CO2 to produce the same energy as a coal unit; therefore, the market trend is credited for a reduction in GHG emissions from the US power sector. However, methane that escapes the natural gas supply chain may undercut these relative climate benefits.
In 2016, Canada, the United States and Mexico pledged to reduce methane emissions from the oil and natural gas sector 40–45% from 2012 levels by 2025. This article reviews the science-policy landscape of methane measurement and mitigation relevant for meeting this pledge, including changes in US policy following the 2016 presidential election. Considerable policy incoherence exists in all three countries. Reliable inventories remain elusive; despite government and private sector research efforts, the magnitude of methane emissions remains in dispute. Meanwhile, mitigation efforts vary significantly. A framework that integrates science and policy would enable actors to more effectively inform, leverage and pursue advances in methane measurement and mitigation. The framework is applied to North America, but could apply to other geographic contexts.
Key policy insights
The oil and gas sector’s contribution to atmospheric methane concentrations is becoming an increasingly prominent issue in climate policy.
Efforts to measure and control fugitive methane emissions do not presently proceed within a coherent framework that integrates science and policy.
In 2016, the governments of Canada, Mexico and the United States pledged to reduce methane emissions from the oil and natural gas sector 40–45% from 2012 levels by 2025.
The 2016 presidential election in the United States has halted American progress at the federal level, suggesting a heavier reliance on industry and subnational efforts in that country.
Collectively or individually, the countries, individual agencies, or private stakeholders could use the proposed North American Methane Reduction framework to direct research, enhance monitoring and evaluate mitigation efforts, and improve the chances that continental methane reduction targets will be achieved.
Combined nutrients and warming massively increase methane emissions from lakes–when nutrient levels were high, warming increased total methane emission by at least six fold and in some cases 17 fold, and the proportion of ebullition increased to 95% of total annual methane flux.
Shallow lakes in agricultural landscapes will emit significantly greater amounts of methane, mostly in the form of bubbles (ebullition) in a warmer world, which is a potential positive feedback mechanism to climate warming. Submerged plants are key predictors of methane ebullition. The combination of warming with the loss of plants appears to transform shallow lakes into methane bubbling machines.
Methane is a potent greenhouse gas with 25 times greater warming potential than carbon dioxide.
Shallow lakes are increasingly recognised as playing an important role in global greenhouse gas cycling. Given the number of shallow lakes globally they potentially have a large influence on atmospheric methane concentrations, which continue to rise.
Methane is released from lakes in a number of ways, both by diffusion of dissolved gas and by bubbles released from the sediments, also called ebullition.
….In the absence of nutrient enrichment, warming alone increased annual methane ebullition by around 50% and its relative contribution to total methane emission rose from about 50% to 75%.
In stark contrast to this, when nutrient levels were high, warming increased total methane emission by at least six fold and in some cases 17 fold, and the proportion of ebullition increased to 95% of total annual methane flux.
….The current study identified the abundance of submerged plants as a key predictor of methane ebullition. However, where plants were abundant, methane ebullition was reduced compared to when plants were absent, even at higher temperatures.
This suggests that through careful management of agricultural landscapes and fresh waters ensuring the proliferation of submerged plants, ebullition of methane can be minimised and in addition ecological condition and fresh water biodiversity will benefit.
Thomas A. Davidson, Joachim Audet, Erik Jeppesen, Frank Landkildehus, Torben L. Lauridsen, Martin Søndergaard, Jari Syväranta. Synergy between nutrients and warming enhances methane ebullition from experimental lakes. Nature Climate Change, 2018; DOI: 10.1038/s41558-017-0063-z
A new study of methane emissions from livestock in the United States ….has challenged previous top-down estimates.
The research was conducted because serious discrepancies exist between top-down estimates that suggest the U.S. Environmental Protection Agency is underestimating agricultural methane emissions by up to 90 percent, and bottom-up estimates accepted by the federal government showing lower emissions.
Top-down emissions estimates involve monitoring atmospheric methane concentrations by satellites or from air samples collected at high altitude by planes, and using models to estimate the sources of emissions. Bottom-up estimates take into account livestock populations and animal emission factors.
In their detailed analysis, researchers used a spatially explicit, bottom-up approach, based on animal inventories and feed-intake-based emission factors, to estimate enteric methane emissions for cattle and manure methane emissions for cattle, swine and poultry for the contiguous United States.
The researchers estimated methane emissions using a “gridded” approach, dividing the U.S. into 0.1 by 0.1-degree GIS units, which created cells from 31 square miles in the northern United States to 42 square miles in the southern part of the country.
….According to the EPA, the top three sources of anthropogenic methane in the United States are the combined energy sector—natural gas, petroleum systems and coal mining—which makes up 40 percent of the total; livestock, 36 percent of the total; and landfills, 18 percent of the total.
…Methane emissions from livestock operations are the result of microbial fermentation and methanogenesis in the forestomach of ruminants and similar fermentation processes in manure from both ruminant and non-ruminant farm animals.
Methane is also produced from enteric fermentation in the digestive tract of non-ruminant herbivore species, such as horses, donkeys and mules, as a result of fermentation processes in their hindgut. However, “hindgut fermenters” do not produce nearly as much methane per unit of fermented feed as ruminants, so enteric or manure emissions from equine species were not included in this analysis. Neither were emissions from small ruminants such as sheep and goats, which are negligible in the U.S.
…Overall, the research, which was published this month in Environmental Science and Technology, yielded total U.S. livestock methane emissions of 19.6 billion pounds per year. However, uncertainty surrounding that total is high, researchers acknowledged.
…predicting methane emissions from manure is a more complex process and carries a larger uncertainty in the estimates, the researchers pointed out. Manure composition, type of storage facilities and manure retention time, and environment—particularly temperature—are among the factors that affect methane emissions from manure.
There is great uncertainty in both enteric and manure methane emissions from livestock, Hristov conceded. He said that research around the world has shown that variability in enteric methane emissions largely can be explained with variability in feed dry-matter intake. Nutrient composition of the feed is also important but has a lesser impact on enteric methane production.
The researchers estimated methane emissions using a “gridded” approach, dividing the US into 0.1- by 0.1-degree GIS units, which created cells from 31 square miles in the northern United States to 42 square miles in the southern part of the country. The study pegged total U.S. livestock methane emissions of 19.6 billion pounds per year. This map shows where they are coming from. Credit: Penn State
Researchers found that some 17 teragrams of the 25 teragram annual increase is from fossil fuel production, 12 is from wetlands or rice farming, while fires are decreasing emissions by 4 teragrams (17 + 12 – 4 = 25).
The huge rise in fossil fuel methane emissions “found here is substantially larger than in previous literature.”
Methane (CH4) traps 86 times as much heat as CO2 over a 20-year period. That’s why countless studies find that even a very small leakage rate of methane from the natural gas supply chain (production to delivery to combustion) can have a large climate impact — enough to gut the entire benefit of switching from coal-fired power to gas for a long, long time.
[see previous post on methane increase globally likely from fracking not from cows here]
A new NASA study is one final nail in the coffin of the myth that natural gas is a climate solution, or a “bridge” from the dirtiest fossil fuels to low-carbon fuels like solar and wind.
NASA found that most of the huge rise in global methane emissions in the past decade is in fact from the fossil fuel industry–and that this rise is “substantially larger” than previously thought. And that means natural gas is, as many earlier studies have found, not a climate solution.
The global-warming potential (GWP) of methane over 20 years and 100 years, with and without climate-carbon feedbacks (cc fb). Via IPCC. https://www.ipcc.ch/pdf/assessment-report/ar5/wg1/WG1AR5_Chapter08_FINAL.pdf (p.731 or 73-79 of pdf)
Natural gas is mostly methane, a potent greenhouse gas. And methane emissions are responsible for about a quarter of the human-caused global warming we’re suffering today….
Today I attended a press conference with Professor Bob Howarth from Cornell’s Methane Project here at the UN climate meetings. My quick notes are below. You can review his highly recommended PowerPoint presentation here and read his press conference handout here. You can also find addition information at his lab’s website here.
From his lab’s research and from the literature (including his talking with the authors on recent literature), Howarth concludes that the natural gas and oil industry is probably contributing twice as much methane as animal agriculture.
Before 2005 no shale gas showed up in global monitoring of methane but now it makes up 60% of global methane and is the most likely candidate for the strong spike in the last decade – not cows and other cattle. This methane spike is showing up almost entirely from US, not other parts of the world (through 2012- that satellite is no longer operational; another one is supposed to be going up soon).
Dr. Howarth made an urgent call for a new approach to measuring methane isotopes (radiocarbon C14) to conclusively identify the sources so that we can quickly reduce this powerful greenhouse gas. He said even if we stopped all of our CO2 production today we’d still feel an impact for 30 to 40 years on global warming – CO2 remains in the atmosphere from 100 to 1000 years. Methane has its biggest impact immediately – within 10 years so reducing methane can have a quick impact on reducing global warming.
He said even the EPA inventory has an estimate of methane that’s way too low and that there is possibly some cover up the actual data (he said more about this afterwards off-camera.
Dr. Howarth said that the number of cows and cattle is lower than a decade ago in North America and in the US so he asked how do you reconcile the methane increase shown through c13 studies and satellite data [its fracking].
He also said that with increases in human population there will be increased demand for meat and more intense use of agricultural lands that would have a negative environmental impact. He said meat production is still a significant contributor to methane and that he believes we should eat less meat and have better handling of methane. He feels that how much methane cows produce is directly related to the type of food they eat.
He said that we’re feeding the world from roughly the same amount of land as in 1960 but doing it with a growing population will have more impact on the land and the environment.
Finally Dr. Howarth said this all goes to the heart of the issue around climate change and the idea of natural gas being a bridge to renewables. It releases more methane than coal.
I asked him afterward what he thought of holistic, prescribed grazing versus industrial cattle production. He said it was his understanding that grass fed is much better than industrial. He had 18 PhD grad students in his class last spring assess the literature and none of them came up with any clear answer. He said the literature is all over the place on this – as we know!
For me it also puts into question the GHG reductions touted by California where there are significant investments in fracking and natural gas.
There has been an alarming uptick in atmospheric methane in recent years, following a flattening of concentrations from 2000 to around 2007
Just from livestock methane emissions, study’s revisions resulted in 11 percent more methane in a recent year than previously estimated– not the biggest contributor to the annual methane budget in the atmosphere, but it may be the biggest contributor to increases in the atmospheric budget over recent years
When it comes to climate change, we know where the most important warming agent — carbon dioxide — is coming from….But the second-most potent greenhouse warming agent — the hard-hitting, if short-lived, gas known as methane — presents more of a mystery. There has clearly been an alarming uptick in atmospheric methane in recent years, following a flattening of concentrations from 2000 to around 2007. But the cause of this particular pattern has been hotly debated, with some blaming the fracked natural gas boom (natural gas is primarily composed of methane) and others pointing to causes such as agriculture.
Now, new research published Thursday in the journal Carbon Balance and Management …. point the finger at agriculture once again. And more specifically, at cattle and other livestock.
“Just from livestock methane emissions, our revisions resulted in 11 percent more methane in a recent year than what we were previously estimating,” said Julie Wolf, lead author of the study who completed the work while a postdoc at the institute and now works at the Department of Agriculture. “It’s not the biggest contributor to the annual methane budget in the atmosphere, but it may be the biggest contributor to increases in the atmospheric budget over recent years…
….Cows and other ruminant animals release methane into the atmosphere as a result of a process called “enteric fermentation” — a technical term that basically refers to the digestive chemistry in the animals’ stomachs. As the Environmental Protection Agency explains, the methane produced in this process “is exhaled or belched by the animal and accounts for the majority of emissions from ruminants.”
Furthermore, the animals’ waste also fills the atmosphere with methane depending on how it is handled, meaning that “manure management” is categorized as a separate source of methane emissions….
Our results suggest that livestock methane emissions, while not the dominant overall source of global methane emissions, may be a major contributor to the observed annual emissions increases over the 2000s to 2010s.
… The study, originally published in the journal PLoS Genetics last year, showed that a cow’s genetics determine which microbes populate its gut — and some of those microbes produce the methane that eventually makes its way into the atmosphere…
… It turned out that the different groups differed in the amounts of methane they emitted — by a lot. “The highest [group emitted] 200 grams per day, and the lowest [group’s] methane emission was at 140 grams per day. So there is a large difference,” says Rainer Roehe, the lead author on the study and a geneticist at Scotland’s Rural College.
Roehe says the different diets made a difference in how much methane the cows emitted, but when they ranked the cow families based on how much gas they were expelling, the least gassy family emitted the least methane no matter what they ate. On the flipside, the cows in the family that gave off the most gas were still the biggest offenders regardless of what they were eating. Roehe says that suggests genetics is playing a big role in shaping which microbes exist in any individual cow’s gut and is the reason why some cows belch and fart less than others….