U.S. Chemical Safety Board

Methane can escape from mines, power plants, farms, and landfills.

Carbon dioxide is the primary driver of climate change, but it’s not the only one. Methane also contributes to warming. In fact, a single molecule of methane causes more warming than a single molecule of carbon dioxide does. But it doesn’t stay in the atmosphere as long, so a new study from NASA affirms what others have suggested for years: that cutting methane emissions would show quicker results than cutting CO2 emissions. The same goes for soot, also known as black carbon. Plus, cutting back on soot would put a damper on the respiratory diseases it causes, and capturing more methane, which is basically natural gas, would save money.

NPR’s Christopher Joyce reports on the study for All Things Considered. He talked to Durwood Zaelke, who runs the Institute for Governance and Sustainable Development in Washington, D.C.

Zaelke is a grizzled veteran of the climate wars: he was in Kyoto in 1997 when the world’s nations drafted a treaty promising to curb warming, and he has watched that promise fizzle while the planet’s temperature continues to rise.

Zaelke says the Kyoto treaty focused too much on the main greenhouse gas: carbon dioxide.

“I mean, it’s like picking a fight with the biggest bully in the schoolyard,” he says with a note of lament. “You know, you get your lunch money stolen, you get your pants pulled down, and you get sent home humiliated. We’ve made about that much progress with CO₂.”

Cutting down on methane and soot alone won’t solve climate change, but the scientists in the study say they expect they could “reduce projected global mean warming [by about] 0.5°C by 2050.”

The article, “Simultaneously Mitigating Near-Term Climate Change and Improving Human Health and Food Security,” by lead author Drew Shindell, was published in Science (the full article is available for a fee).

A rice field in the Sacramento Valley. According to NOAA, rice paddies are a source of methane emissions. Photo: Craig Miller

Despite all the focus on regulating CO2 as a way to combat global warming, a new NOAA study finds that to really put the brakes on climate change, the world can’t ignore the other greenhouse gases.

The study takes an inventory of non-carbon greenhouse gases including methane, which emits from landfills and farms, and nitrous oxide, which primarily comes from soil management and combustion. Per molecule, the study notes that these gases have a stronger muscle for trapping heat compared with carbon dioxide, but they don’t last as long in the atmosphere.

“This study looks at what would happen if society decided to go after the short-lived greenhouse gases, as well as CO2.” said Jim Butler, Director of Global Monitoring at NOAA and author of the study.

Short-lived is a relative term in atmospheric science. Butler said it takes decades for methane to fully run its course in the atmosphere, during which its potential to trap heat is much greater, even though its share in the atmosphere is pennies compared to that of CO2.

Carbon dioxide sticks around much longer, some of it for thousands of years, said Butler.

“CO2 is still the big dog in the fight,” he said.

The warming impacts from all human-based greenhouse gases. At 390ppm, CO2 leads the pack but other greenhouse gases like methane, at 1.8ppm, and nitrous oxide, at 0.3ppm, have a measurable impact.. Table: NOAA

Butler said that the concentration of carbon dioxide in the atmosphere is now at 390 parts per million and is responsible for 63% of all greenhouse gas warming influence, as shown in the NOAA chart above.  The study equates this warming influence to the heat generated from nine trillion, 100-watt light bulbs.

Butler likens this persistent heating effect to a hot electric blanket.

“If we cut emissions, the [heat of] blanket would still go up by a bit,” said Butler.  “We can’t turn the blanket back down very fast.”

A graph showing the outcomes between the current emissions trajectory (in red) and a scenario where CO2 and non CO2 greenhouse gases are cut by 80% of 2008 levels (in green). Graph: NOAA

The NOAA scientists graphed the “electric blanket” heating outcomes under different emissions scenarios. Even under the most optimistic scenario, where 80% of all greenhouse gases are cut, the study finds it will take 40 years before the blanket’s thermostat goes down.

“The long-term necessity of cutting carbon dioxide emissions shouldn’t diminish the effectiveness of short-term action,” said Butler in a press release. “Managing emissions of non-carbon dioxide gases is clearly an opportunity to make additional contributions.”

Cows at Fiscalini Farms in Modesto, California. (Photo: Sheraz Sadiq)

Last year, as part of a radio series on methane, I drove down to visit John Fiscalini, who was building a huge methane “digester” to convert his cows’ “byproducts” into clean energy, and reduce the carbon footprint of his sizable dairy farm and cheese factory outside Modesto.  After millions of dollars in design and construction costs, Fiscalini was fed up with state air and water regulators, who he felt were pulling him in different directions. A year later, have things improved? Not so much, as Quest’s Lauren Sommer found out, when she returned to the San Joaquin Valley for an update. — Craig Miller

Three years ago, KQED’s QUEST visited a Central Valley dairy that was taking an innovative approach to its waste problem. Instead of collecting thousands of pounds of cow manure in open holding ponds, Joseph Gallo Farms uses it in a renewable energy technology known as a methane digester.

Methane gas is a natural byproduct of cow digestion. It’s produced as bacteria inside their stomaches break down food. That process continues on the back end (so to speak) as cow manure decomposes.

Methane is also a powerful contributor to climate change – about 21 times stronger than carbon dioxide. The UN has estimated that 18 percent of greenhouse gases worldwide come from livestock.  (Last year, Climate Watch reported on methane and it sources in this two-part radio series.)

By capturing methane, dairy digesters keep it out of the atmosphere. But they also create a source of renewable energy. Methane is a natural gas — it can be burned just like propane. So, Gallo Farms pipes the methane over to a generator, which produces enough electricity to run the farm and their cheese plant.

Since our visit, the story has taken an interesting turn. Both Gallo Farms and another dairy with a digester, Fiscalini Farms, are located in the San Joaquin Valley, an area with some of the worst air quality the country. The air district is consistently considered in “non-attainment,” which means they aren’t meeting the federal limits on air pollution.

While both dairies’ digesters are reducing one kind of pollution, greenhouse gases, they’re actually adding to another kind. Generators, like any other combustion engine, produce nitrous oxide pollution – or NOx – which is a component of smog. Given the smog problem in the valley, the local air district decided to put a pollution limit on the dairy digester generators.

Since then, both dairies have struggled to meet to the limits. Unlike pipeline-quality natural gas, the methane (or biogas) that comes from a digester varies in quality, which affects how much pollution is produced in the generator’s exhaust. John Fiscalini of Fiscalini Farms has spent $200,000 on a pollution control device that reduces NOx pollution. But he says it’s been a challenging process and he’s concerned that other dairies have been discouraged by his experience with regulators.

For more on Fiscalini’s story and more about the challenges facing dairy digesters, check out this week’s QUEST radio story.

By Cody Sheehy

A couple of months ago, nearly lost amid the “Hopenhagen” hype,  the University of California, Davis (UCD) put out a press release with an admonition: “Don’t Blame Cows for Climate Change.” The release was a first look at some work conducted by UCD Associate Professor and Air Quality Specialist Frank Mitloehner. His study examines the greenhouse gases, or GHGs, emitted by the livestock sector.  As California’s air regulators turn more attention toward methane in particular, the report remains timely.

Mitloehner’s paper is entitled: “Clearing the Air: Livestock’s Contributions to Climate Change,” and was published in the peer-reviewed journal Advances in Agronomy. The paper is a synthesis of current science on the cattle-climate connection. Mitloehner has been updating some of that science in recent years.

In 2008, I stopped by his cluster of “bio bubbles;” airtight domes that serve as high-tech stables for cows. Inside, Mitloehner had set up simulated dairy operations, measuring GHGs emitted by the cows’ digestive process and decomposition of the manure. The numbers then in common use had been generated in the 1930s.

Research "bio-bubbles" at UC Davis. Photo: Cody Sheehy

Mitloehner says cattle gets a bum rap in the media, and points to some examples, including a 2007 story in Time magazine, which included assertions like: “Which is responsible for more global warming: your BMW or your Big Mac? Believe it or not, it’s your Big Mac,” and “A 16-oz T-bone is like a hummer on a plate . . ”

In many cases, Mitloehner says the statements are crafted from an influnencial 2006 United Nations report entitled: “Livestock’s Long Shadow.”  According to the executive summary, “The livestock sector is a major player, responsible for 18 percent of greenhouse gas emissions measured in CO2 equivalent. This is a higher share than transport.”

But Mitloehner points to a quote deeper in the report:

“The respiration of livestock makes up only a very small part of the net release of carbon that can be attributed to the livestock sector. Much more is released indirectly by other channels, including: the burning of fossil fuel to produce mineral fertilizers used in feed production, methane release from the breakdown of fertilizers and from animal manure, land-use changes for feed production and for grazing, land degradation, fossil fuel use during feed and animal production and fossil fuel use in production and transport of processed and refrigerated animal products.”

Mitloehner cautions that the transportation number they use only accounts for tailpipe emissions. To be even-handed, he says, the authors should’ve incorporated emissions from the entire oil industry, including refinement of the oil and production of cars. In the UCD release, Mitloehner calls it a “lopsided ‘analysis” and “a classical apples-and-oranges analogy that truly confused the issue.”

Meanwhile, the Bio-bubbles have been generating some interesting numbers. Mitloehner found that the amount of methane the cows respire (belch) and how much is released in the breakdown of animal manure is quite different from what previous research had calculated. In combination, these two sources represent the most direct GHGs from the livestock industry, even if they’re not the largest GHG emitter associated with the industry. They’re also the most out of date.

Emission factors used in “Livestock’s Long Shadow” provide an estimate of methane respiration of about 86 million tonnes (metric tons) of methane (CH4) and 17.5 million tonnes of CH4 annually from manure decomposition. In the annex of the UN report, the authors write: “Obviously, great improvements to the estimates of emission factors could be made if more data on nutrition and production were available.” And so it is that inside his bio-bubbles, Mitloehner has come up with numbers much lower than those that represented the conventional wisdom since 1938.

All in all, we’ve got a discussion about comparing apples and oranges (more appealing than manure, granted) and some updated numbers that lower the emissions of livestock in one category. As with any scientific paper, there will probably be debate on both of these points and new ones, but let’s look at the broader consequences. Will industry look at this study and see an incentive to update and revise carbon emission numbers all across the board?

According to Emilo Laca, an agricultural ecologist at U. C. Davis, some of these questions will be fodder for policy debates that lie outside the realm of science. He says “The real question is, ‘How are we going to split this up?’” Laca used a hypothetical problem to explain: Let’s say that a certain livestock industry consumed 30% of soybean production as a food source. Livestock producers might concede that they should be accountable for 30% of carbon emissions related to soybeans. It makes sense. It’s what the numbers say. Others might counter that without this certain livestock industry, the soybean market would behave differently and some amount–lets guess 70%–wouldn’t need to be planted. Therefore, the livestock industry in this example is responsible for 70% of the emissions, not 30%. Science can support both interpretations. As Laca says, the decision is how to “split” things up. And ultimately, those decisions may fall to policy wonks.

This tower in Walnut Grove is rigged with equipment to detect and measure atmospheric gases, monitored by NOAA. Photo: Craig Miller

A companion radio piece to this post aired on The California Report.

Scientists in California have begun setting up a statewide network of monitors to track California’s greenhouse gas emissions. Similar equipment has been in place for years as part of a continental network established by the National Oceanic & Atmospheric Administration (NOAA). But officials at the California Air Resources Board (CARB) say this new system will be the first of its kind.

“The unique thing about this is that we’re actually looking at the local emissions, rather than the global average, says Jorn Herner, who heads the Greenhouse Gas Technology & Field Testing Section of CARB’s research arm. “Nobody has done that before.”

Scientists have been systematically tracking atmospheric CO2 on a broad scale since 1958. California’s network of GHG sniffers will be capable of tracking CO2, nitrous oxides and other known greenhouse gases, and will initially focus on methane.

But CARB officials say the network is not part of a “Big Brother” strategy for emissions compliance. “This is initially a research project,” said Herner. He says the new network will provide a “second data point” to augment the state’s current method of estimating GHG emissions. Currently California’s current climate law, AB-32, relies on a “bottom-up” system of estimating emissions from individual sources, then adding them up to arrive at total emissions for the state.

“The modeling won’t tell you each individual source but what you’d be able to do is develop a gridded inventory. So you’ll be able to say in this square mile of land over here, it looks like emissions are much higher than in this square mile next to it.”

The greenhouse gas analyzers are about the size of a desktop computer. Photo: Craig Miller

The Air Board has purchased seven “next-generation” analyzers from Picarro Instruments in Sunnyvale. Five will go to fixed locations, such as a tower on Mt. Wilson, above the Los Angeles Basin. The two others will be on “mobile platforms;” electric vehicles that can roam the state taking ground-level readings. The units cost about $50,000 apiece but Picarro executives say they are self-adjusting and require far less human intervention than previous models, which will ultimately make them more cost-effective.

Picarro’s CEO, Michael Woelk, says a nationwide network of 500-to-700 detectors could yield a comprehensive GHG map of the US with resolution down to ten kilometers (a little more than six miles).

If California regulators are successful at putting in place a statewide or regional cap-and-trade system for greenhouse gases, industrial emitters will have to pay fees for the carbon they pump into the air. Horn agrees that at that point, some kind of check on the current system of self-reporting will “probably” be needed, but, he says, “that’s not the goal of this monitoring network at this time.”

“The science is really young,” he explained. “We’re really just trying to find out the potential of what we can do with this network. How it’s used in the future is still up in the air.”

…so to speak.

This animation below shows the methane levels detected by a Picarro analyzer as it is driven from Livermore, CA, to Sacramento.

A Tulare County dairyman is using cow “emissions” to fuel two delivery trucks. Instead of a sleeper compartment, the cab of the truck holds six lightweight tanks for compressed bio-methane.

Western United Dairymen have produced a video about the project and its benefits to the environment. That’s an interesting twist because the dairy lobbying group and air quality regulators haven’t always seen eye to eye on the question of bovine gas.

Emissions from livestock have their own load of air quality issues, especially in Tulare County, where there are more cows than people. When cows burp or emit gas, it produces ozone, a key component of smog. Dairy owners have also wrangled with air regulators over emissions from some methane digesters that convert manure to electricity on dairies. For a refresher (poor word choice, perhaps), check out our recent radio/web series on methane.

But the California Air Resources Board stands behind the cow-power project (though perhaps not the manure spreaders–okay, old joke). In fact, CARB staked the dairy to a $600,000 grant, under legislation passed in June 2006 to encourage the introduction of alternative fuels into the California market. Hilarides Dairy and Cheese company used the money to help build a methane digester and figure out how to convert the diesel trucks.

How exactly does cow poop become something that can power a vehicle? It isn’t pretty, according to the group Sustainable Conservation, which put out a report on the subject. It goes something like this:

Manure is flushed from the cows’ stalls into a covered lagoon where bacteria convert the manure to biogas. The trapped gas is sent from the lagoon to a biogas upgrading system which removes impurities. Pressurized bio-methane is put into the truck’s fuel tank. The truck is then ready for the road.

The report estimates that cows could eventually power a million cars nationwide. But unless you live near a dairy farm or have your own personal cow to hook up to your fuel tank, don’t expect this will save you a trip to the gas station anytime soon.

Photo courtesy of Hilarides Dairy: The biogas upgrading system arrives by truck from Michigan (but transported with conventional diesel).

At Fiscalini Farms near Modesto, John Fiscalini says he finally worked out a deal with air regulators that allows him to convert his manure into methane for electric power. His permit from the San Joaquin Valley Air Pollution Control District allows him to run the engine while he makes adjustments to minimize particulate and nitrous oxide pollutants.

He hopes to be making power by the middle of this month–more than 13 months behind schedule. Capturing the methane, of course, will make a significant dent in the carbon footprint of the farm, which has 3,000 cows (1,500 producing and 1,500 “replacements”).

He also has a grant from the U.S. Dept. of Energy, under which university researchers will install equipment to monitor the methane operation. Fiscalini says they’ll “monitor everything we can possibly monitor” and gather data to make better judgments about the efficiency and economic feasibility of methane digesters. He’s having some doubts about the economic feasibility of his own. Now, he says, water quality regulators want him to do $40,000 worth of environmental assessments, including a hydro-geologic survey and a study of his waste stream (he uses leftovers from the methane digester for fertilizer).

You may recall that we started Part One at an unidentified landfill, to explain how methane is produced and captured, and why flaring it off is better than letting the methane escape into the atmosphere. I later heard from Jessica Jones, district manager for Waste Management, which runs the Redwood Landfill and Recycling Center in Marin County, the location where I did the recording. While the landfill currently flares off its collected methane, Jones wanted us to know about some of the company’s efforts to harness that gas–potentially enough to power 4,000-5,000 homes. In an email to KQED, she wrote:

“Redwood Landfill is currently working to permit a landfill gas to energy facility which will become Marin County’s largest source of green power.  Altamont Landfill in Alameda County currently has landfill gas to energy production through the use of internal combustion engines and turbines, and is beginning construction of a liquefied natural gas facility which will convert landfill gas into a clean burning fuel which can be used to power Waste Management’s refuse collection fleet.  This type of fuel is estimated to be potentially the closest to carbon neutral of any fuel being developed today.”

There’s more about Redwood’s landfill-gas-to-energy (LFGTE) project at the company’s website. In echoes from our conversations with John Fiscalini, Jones writes on the site that there are “regulatory hurdles” to be cleared before this can happen. Sound familiar?

Photo: Stinky silage; Methane digester tanks will soon power the Fiscalini dairy farm.

Two recent climate studies were highlighted on KQED’s Forum program today. Host Dave Iverson invited me to join him, along with UC Berkeley researcher Inez Fung, author of a new study on seasons shifting from rising temperatures, and Phil Van Mantgem, who led a new USGS study on the alarming rise in tree mortality across the western U.S.

Van Mantgem then popped up on NPR’s Science Friday, followed by New York Times correspondent Andrew Revkin, author of the widely followed Dot Earth blog, who responded to recent polling on changing attitudes toward climate change.

Podcasts of both programs are available at their respective websites (linked above).

This coming week, we’ll begin our two-part series on methane’s contribution to global warming. Part One airs on The California Report on Monday morning, followed by Part Two a week later. Part One examines where methane comes from and why regulators are looking at it with new concern. In Part Two, we’ll visit a dairy farm near Modesto, where methane from cow manure is being captured and turned into electric power and steam–but not without considerable expense and frustration with regional air & water quality regulators.

No one said that climate change was simple.

Neither are the solutions, apparently.  An article in the LA Times reports on the “dark side” of solar, outlining the toxic materials used in cells, the difficulty of recycling some components, and the fossil fuels burned in the production and transportation process of cells and panels.

And don’t let this weird weather confuse you either.  As the Thin Green Line reports, this week’s freezing temperatures in the Midwest don’t mean climate change isn’t happening.

According to a study published by researchers at MIT, there was a global spike in atmospheric methane last year. The increase, on the order of millions of metric tons, was uniform around the world, not concentrated around major methane emitters, as one might expect. In other words, “background” methane levels are up all over, so that the atmospheric concentration is nearly 1800 parts per billion.

That’s a much lower concentration than carbon dioxide, which stands at about 385 parts per million. Methane also breaks down faster in the atmosphere. But it worries climatologists because it is far more potent than CO2 as a greenhouse gas; anywhere from 25 to 50 times more harmful, depending on how you measure it. Researchers Matthew Rigby and Ronald Prinn say atmospheric methane levels have more than tripled since the Industrial Revolution but has held steady in recent years. Recently something has thrown it out of balance but the MIT team could only speculate about possible reasons.

Methane escapes from a combination of both natural and human-induced sources. It leaks from oil & gas industry infrastructure and landfills, and is produced by livestock (and human) digestion. It’s also released by marshes and rice paddies. California is a major rice producer but the rice fields’ share of total U.S. methane emissions is relatively tiny.

Climate Watch is preparing an upcoming feature on  methane and climate change. Listen for it on The California Report in November.