Global warming will cause ecosystems to produce more methane than first predicted

Date:
June 29, 2020
Source:
Queen Mary University of London
https://www.sciencedaily.com/releases/2020/06/200629120210.htm

New research suggests that as the Earth warms natural ecosystems such as freshwaters will release more methane than expected from predictions based on temperature increases alone.

The study, published today in Nature Climate Change, attributes this difference to changes in the balance of microbial communities within ecosystems that regulate methane emissions.

The production and removal of methane from ecosystems is regulated by two types of microorganisms, methanogens — which naturally produce methane — and methanotrophs that remove methane by converting it into carbon dioxide. Previous research has suggested that these two natural processes show different sensitivities to temperature and could therefore be affected differently by global warming.

Research led by Queen Mary University of London and the University of Warwick studied the impact of global warming on freshwater microbial communities and methane emissions by observing the effect of experimental warming of artificial ponds over 11 years. They found that warming produced a disproportionate increase in methane production over methane removal, resulting in increased methane emissions that exceeded temperature-based predictions.

Professor Mark Trimmer, Professor of Biogeochemistry at Queen Mary, said: “Our observations show that the increase in methane emissions we see is beyond what you could predict based on a simple physiological response to the temperature increase. Long-term warming also changes the balance in the methane-related microbial community within freshwater ecosystems so they produce more methane while proportionately less is oxidised to carbon dioxide. As methane is a far more potent greenhouse gas than carbon dioxide, together these effects increase the global warming potential of the carbon gases released from these ecosystems.”

The experimental observations were supported by a meta-analysis of available data on methane emissions collected from wetlands, forests and grasslands worldwide, which showed that naturally warmer ecosystems also produce disproportionately more methane.

Professor Trimmer, said: “Our findings fit with what we see in the real world for a wider variety of ecosystems. Together these results suggest that as Earth temperatures increase through global warming, natural ecosystems will continually release more methane into the atmosphere.”

Dr Kevin Purdy, Associate Professor of Microbial Ecology at Warwick, added: “Our studies have led to a better understanding of how global warming can affect methane emissions from freshwaters. This means that future predictions of methane emissions need to take into account how ecosystems and their resident microbial communities will change as the planet warms.”

Methane is a powerful greenhouse gas with some 28 times the global warming potential of carbon dioxide over a 100 year period. Over 40 per cent of methane is released from freshwaters such as wetlands, lakes and rivers making them a major contributor to global methane emissions.


Story Source:

Materials provided by Queen Mary University of LondonNote: Content may be edited for style and length.


Journal Reference:

  1. Yizhu Zhu, Kevin J. Purdy, Özge Eyice, Lidong Shen, Sarah F. Harpenslager, Gabriel Yvon-Durocher, Alex J. Dumbrell, Mark Trimmer. Disproportionate increase in freshwater methane emissions induced by experimental warmingNature Climate Change, 2020; DOI: 10.1038/s41558-020-0824-y

Global warming will cause ecosystems to produce more methane than first predicted

https://phys.org/news/2020-06-global-ecosystems-methane.html

ecosystems
Credit: CC0 Public Domain

New research suggests that as the Earth warms natural ecosystems such as freshwaters will release more methane than expected from predictions based on temperature increases alone.

The study, published today in Nature Climate Change, attributes this difference to changes in the balance of microbial communities within  that regulate  emissions.

The production and removal of methane from ecosystems is regulated by two types of microorganisms, methanogens—which naturally produce methane—and methanotrophs that remove methane by converting it into . Previous research has suggested that these two natural processes show different sensitivities to temperature and could therefore be affected differently by .

Research led by Queen Mary University of London and the University of Warwick studied the impact of global warming on freshwater microbial communities and methane emissions by observing the effect of experimental warming of artificial ponds over 11 years. They found that warming produced a disproportionate increase in methane production over methane removal, resulting in increased methane emissions that exceeded temperature-based predictions.

Professor Mark Trimmer, Professor of Biogeochemistry at Queen Mary, said: “Our observations show that the increase in methane emissions we see is beyond what you could predict based on a simple physiological response to the temperature increase. Long-term warming also changes the balance in the methane-related microbial community within freshwater ecosystems so they produce more methane while proportionately less is oxidised to carbon dioxide. As methane is a far more potent greenhouse gas than carbon dioxide, together these effects increase the global warming potential of the carbon gases released from these ecosystems.”

The experimental observations were supported by a meta-analysis of available data on methane emissions collected from wetlands, forests and grasslands worldwide, which showed that naturally warmer ecosystems also produce disproportionately more methane.

Professor Trimmer, said: “Our findings fit with what we see in the real world for a wider variety of ecosystems. Together these results suggest that as Earth temperatures increase through global warming,  will continually release more methane into the atmosphere.”

Dr. Kevin Purdy, Associate Professor of Microbial Ecology at Warwick, added: “Our studies have led to a better understanding of how global warming can affect methane emissions from freshwaters. This means that future predictions of methane emissions need to take into account how ecosystems and their resident microbial communities will change as the planet warms.”

Methane is a powerful greenhouse gas with some 28 times the global  potential of carbon dioxide over a 100 year period. Over 40 per cent of methane is released from freshwaters such as wetlands, lakes and rivers making them a major contributor to global *.


Explore further

Study shows global warming could push methane emissions from wetlands 50 to 80 percent higher

Satellites reveal major new gas industry methane leaks

LONDON (Reuters) – Last fall, European Space Agency satellites detected huge plumes of the invisible planet-warming gas methane leaking from the Yamal pipeline that carries natural gas from Siberia to Europe.

A undated handout image shows methane emission hotspots associated with oil, gas and coal between January 2019 and May 2020. KAYRROS/Handout via REUTERS

Energy consultancy Kayrros estimated one leak was spewing out 93 tonnes of methane every hour, meaning the daily emissions from the leakage were equivalent to the amount of carbon dioxide pumped out in a year by 15,000 cars in the United States.

The find, which has not been reported, is part of a growing effort by companies, academics and some energy producers to use space-age technology to find the biggest methane leaks as the potent heat-trapping gas builds up rapidly in the atmosphere.

Kayrros, which is analysing the satellite data, said another leak nearby was gushing at a rate of 17 tonnes an hour and that it had informed Yamal’s operator Gazprom (GAZP.MM) about its findings this month.

Gazprom did not immediately respond to requests for comment about the leaks identified by Kayrros.

Up to now, estimates of greenhouse gas emissions from industries have relied mainly on paper-based calculations of what’s pouring out of tailpipes and smokestacks, based on the amount of energy consumed by people and businesses.

But as satellite technology improves, researchers are starting to stress test the data – and the early results show leaky oil and gas industry infrastructure is responsible for far more of the methane in the atmosphere than previously thought.

Such a revelation would heap pressure on energy companies – already targeted by climate activists and investors for their contribution to carbon dioxide emissions – to find and plug methane leaks.

The new satellite discoveries of methane leaks could also lead to more stringent regulatory regimes targeting natural gas, once seen as a “clean” fossil fuel, as governments seek to combat climate change, experts say.

While scientists generally agree that calculating emissions based on consumption works well for carbon dioxide, it is less reliable for methane, which is prone to unexpected leaks.

Methane is also 80 times more potent during its first 20 years in the atmosphere and scientists say that identifying methane sources is crucial to making the drastic emissions cuts needed to avoid the worst impacts of climate change.

 

“What this now shows is that the avoidance of that fossil leakage actually can have a larger impact than what was anticipated earlier,” said Imperial College London climate scientist Joeri Rogelj, who is one of the authors for reports by the Intergovernmental Panel on Climate Change (IPCC).

GRAPHIC: Global methane intensity on the rise – here

Reuters Graphic

PIVOTAL DISCOVERY

A study in February’s Nature magazine reinforced the idea that the oil and gas industry produces far more methane than previously thought as it suggested emissions of the gas from natural causes have been significantly overestimated.

The findings don’t let farming off the hook – it’s still responsible for a quarter of the methane in the atmosphere – but they suggest mud volcanoes and natural oil and gas seepages have been taking some of the heat for the energy industry’s leaks.

Some big oil and gas companies such as BP (BP.L) and Royal Dutch Shell (RDSa.L) are tackling the issue by investing in satellite companies or signing monitoring deals so they can find and plug their leaks and stick to pledges to slash emissions.

The push to detect emissions from the sky began when U.S. advocacy group Environmental Defense Fund (EDF) and universities including Harvard used aerial measurements to show methane leaks from America’s oil and gas heartland were 60% above inventories reported to the U.S. Environmental Protection Agency.

That 2018 report was pivotal, said Christophe McGlade, a senior researcher at the International Energy Agency (IEA).

“What they found from actual ground and aerial measurements is that the engineering-based approach can really underestimate total emissions,” he said. “Maybe if emissions were higher in the United States than previous estimates, maybe they were higher in other parts of the world too?”

A year later, Canadian greenhouse gas monitoring company GHGSat found another major leak at pipeline and compressor infrastructure near the Korpezhe field in Turkmenistan.

 

In an October report, GHGSat estimated the leak released 142,000 tonnes of methane in the 12 months to the end of January 2019 and said then it was the biggest on record.

GHGSat said the leak was plugged in April 2019 after state oil company Turkmen Oil was notified. Turkmen Oil officials could not be reached for comment. The company declined to comment when asked about it in November.

“That one emission that we found together represents about one million cars taken off the road per year,” said GHGSat founder Stephane Germain.

Now, the more recent Kayrros discovery has added to the evidence that undetected methane leaks from the energy industry are a global issue – and a major one.

RUSSIA IN THE SPOTLIGHT

Kayrros said its analysis of the satellite data showed concentrations of methane around compressor stations along the pipeline linking Russian gasfields to Europe.

The Yamal-Europe pipeline stretches 2,000 km (1,250 miles) from Germany through Poland and Belarus to Russia where it joins the 2,200 km SRTO–Torzhok pipeline to Siberia’s gasfields.

Gazprom (GAZP.MM) estimated that about 0.29% of the 679 billion cubic metres of gas it moved through its pipeline network escaped as methane emissions in 2019. Yamal has an annual capacity of about 33 billion cubic metres.

“These figures correspond to the best global practices,” Gazprom said in a June 10 statement about its emissions.

Kayrros also discovered leaks from oil and gas installations in the Sahara Desert in North Africa.

“Early results show that the estimates we have been relying on for the last years and decades are probably too low and we’re finding more methane coming out of various industries and regions than we thought was the case,” said Christian Lelong, director for natural resources at Kayrros.

McGlade said the IEA increased the projected contributions of several countries in central Asia and North Africa in its Methane Tracker this year because of the satellite detections.

An undated handout image shows methane hotspot on the Yamal pipeline. KAYRROS/COPERNICUS SENTINEL DATA 2019-2020/Handout via REUTERS

He singled out Russia as one country where official methane emissions estimates were likely too low.

According to current IEA estimates of methane emitting countries, Russia is closely followed by the United States, with other large oil and gas producers such as Iraq, Iran and Saudi Arabia further down the list.

“Our estimates suggest that Russia is actually among the higher emitters globally. There does appear to be evidence from satellites of leaks along some of its large gas pipeline routes,” McGlade said.

The Kremlin did not immediately respond to requests for comment about the IEA estimates.

GRAPHIC: Russian methane emissions estimates – here

Reuters Graphic

MORE SATELLITES

The scrutiny from space is set to intensify. GHGSat aims to launch two new satellites this year while the EDF advocacy group plans to launch its own satellite in 2022.

The U.S. National Aeronautics and Space Administration (NASA) is also working on a satellite monitoring programme for greenhouse gas emissions, specifically in the United States.

Shell signed a deal with GHGSat last year to work towards covering its sites globally, saying it hopes to get its methane leakage rate down to 0.2%, or below, by 2025.

BP is planning to cover its sites with constant measurements by 2023 and invested $5 million this month in Satelytics, an analytics firm that tracks methane emissions using satellites.

BP, Shell and U.S. non-profit EDF – along with Eni (ENI.MI), Total (TOTF.PA), Equinor (EQNR.OL) and Wintershall Dea – sent policy recommendations to the European Union in May, asking the world’s biggest gas importer to standardise the gathering of methane emissions data by 2023, using satellite technology.

U.S. oil companies have also been exploring ways to detect methane emissions, said Howard Feldman, senior director for regulatory and scientific affairs at the American Petroleum Institute.

Exxon Mobil Corp (XOM.N), for example, said this year it was field testing eight detection methods, including satellites and aerial surveillance with drones, helicopters and planes.

GRAPHIC: Sources of Russian methane – here

Additional reporting by Vladimir Soldatkin; Editing by Richard Valdmanis, David Clarke and Jon Boyle

MORE FROM REUTERS

Good moos: methane from cows matters less in climate change, says Irish researcher

Methane from cattle should be counted on a different basis from other emissions, according an Irish academic
Methane from cattle should be counted on a different basis from other emissions, according an Irish academic
ALAMY

Scientists have overestimated the effect of agriculture methane emissions on climate change, an Irish academic believes.

Shane McDonagh, an environmental researcher at UCC, said Ireland has been measuring the impact of farming on carbon emissions in the wrong way leading to an overestimation of the negative impacts on our carbon footprint.

Agriculture in Ireland accounts for 33 per cent of all greenhouse gas emissions compared with 10 per cent in the EU as a whole. Most farm-related emissions are from methane gas, which has a global warming potential 84 times greater than carbon dioxide (CO2) over 20 years and 28 times greater over 100 years. Methane gas breaks down into CO2 over time, and loses global warming potential.

CO2, while less potent than methane,

Permian Basin Methane Emissions Found to Be More Than 2x Previous Estimates

ENERGY

A gas flare burns in the Permian Basin in Texas. Bronte Wittpenn / Bloomberg Creative Photos

The largest oil and gas producing area in the U.S. is emitting more than twice as much methane as previously believed.

“Our study found that the quantity of methane emitted in the Permian Basin [is] the highest ever measured from any U.S. oil and gas basin. This is a really big deal from a climate standpoint,” lead authors Harvard atmospheric scientist Yuzhong Zhang and EDF scientist Ritesh Gautam said in an email to Bloomberg Wednesday.

The Permian Basin, which straddles West Texas and New Mexico, produces more than a third of the country’s oil and 10 percent of its natural gas, according to CBS News. The researchers used 200,000 individual readings from the European Space Agency’s TROPOMI satellite instrument to determine the field was leaking 3.7 percent of the methane it produces, EDF reported. That’s more than two times the U.S. Environmental Protection Agency (EPA) estimate, according to InsideClimate News. It’s also enough wasted gas to power 7 million Texas homes and as much greenhouse gas pollution as the carbon dioxide emissions of all U.S. homes, the study found.

What’s more, it nearly triples the climate impact of the natural gas produced in the region over the last 20 years, according to EDF, challenging the argument that natural gas can be a cleaner bridge fuel in the transition from coal to renewable energy.

“The most up-to-date thinking is that for comparing coal and natural gas to generate electricity, gas is worse than coal if the methane emission rate is greater than 2.7%,” Cornell University methane expert Dr. Robert Howarth, who was not involved in the study, told CBS News. At 3.7 percent, the Permian Basin leakage rate definitely fits the bill.

Methane is so dangerous for the climate because it is around 28 times more powerful than carbon dioxide at warming the planet over 100 years and more than 80 times more powerful over 20 years, according to National Geographic. Because it only stays in the atmosphere for 12 years, however, reducing its emissions can have a more immediate impact on fighting global warming, InsideClimate News pointed out.

The increased emissions are partly linked to the rise of fracking, which, along with horizontal drilling, has driven the increase in U.S. oil and gas production since 2005, according to CBS News.

“After staying level for the first decade of the 21st century, methane emissions have been rising quickly over the past decade,” Howarth told CBS. “My research indicates that shale gas development in the U.S. is responsible for at least one-third of the total increase in these emissions globally.”

The study’s authors had several recommendations for how oil and gas producers could reduce methane emissions, such as improving design, management, regulation and infrastructure.

However, the Trump administration is making it easier for the industry to sidestep improvements.

“Trump’s EPA has proposed to substantially weaken or even eliminate regulations, adopted during the Obama administration, to control methane emissions from oil and gas facilities,” Romany Webb, a senior fellow at the Sabin Center for Climate Change Law at Columbia Law School, told CBS.

There is also the question of how the fall in oil demand prompted by the coronavirus pandemic will impact methane emissions. The data in the study was collected over 11 months in 2018 and 2019, when production and demand was normal.

“There is going to be a lot less wells being drilled, probably less gas being flared, even wells [that] will [probably] be shut in,” study coauthor and EDF scientist David Lyon told InsideClimate News. “If that is done properly, then I think you will have less emissions. At the same time, I wouldn’t be surprised if a lot of operators cut back on their environmental staff and they do [fewer] leak inspections and other activities that would reduce emissions. They may have less ability to respond to malfunctions and things that cause emissions.”

https://www.ecowatch.com/permian-basin-methane-emissions-2645852936.html?rebelltitem=5#rebelltitem5

The Ground Is Filled with Fire Ice. What Happens If We Pull It All Out?

This world superpower just extracted a record amount of the gas trapped in frozen water.

https://www.popularmechanics.com/science/a32209385/fire-ice-methane-gas-hydates/

LOUISE MURRAY / ROBERTHARDING
  • China has pulled a record amount of clathrate hydrate natural gas from the South China Sea.
  • Methane hydrate is the result of specific environmental conditions that make it very hard to mine.
  • This is just one kind of clathrate, but the family can include many elements and shapes.

China’s natural gas industry has announced a record amount of “fire ice” extracted from the South China Sea. If that sounds like something out of a twisty George R. R. Martin novel, the truth is arguably more intricate.

This coy term refers to methane hydrates, the natural-gas-and-water version of an overall category called clathrates. In a clathrate, one kind of molecule forms a scaffold or lattice that traps another kind of molecule.

In a methane hydrate, ice crystals trap natural gas and hold it basically forever unless something intervenes. Like shale oil, this natural gas is held in place. But if you could cut a cube of oil shale out of the ground, the oil would still be in there. Methane hydrate begins to melt as soon as you move it from its frozen origin place, so extracting it is both financially and environmentally risky.

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This is why fire ice is unusual as a product, despite possibly being the most plentiful hydrocarbon on Earth, Oil Price explains. Investors were shy about it before, but now oil prices are “negative,” and experts are concerned about how we’ll responsibly expose of the existing pipeline of oil if need be. For China to take big public steps to add even more supply is an interesting decision. But it could also mean energy independence for the country—and even during a global lockdown, the most populous nation on Earth has needs.

For now, let’s focus on how clathrates form, and how they really work in nature.

The vast majority of naturally occurring clathrates are methane hydrates, like those found in the South China Sea. Sometimes, methane hydrates have formed in manmade situ and caused complications. London South Bank University water scientist Martin Chaplin explains:

“Clathrates are notable due to their hazardous formation in natural gas pipeline blockages, their occasional hazardous release of large volumes of gas from underwater natural reservoirs, their potential for the production of natural gas from deep-sea sources and their potential in the removal of the global-warming gas, carbon dioxide.”

A surprising 2016 paper suggested that clathrate structure could be the answer to a food science question: How can we carbonate solid foods in a way similar to soda or champagne? “Clathrate hydrate can store large amount of gas molecules. For example, CO₂ concentration in clathrate hydrate is 20–50 times higher than that in carbonated water. Then, clathrate hydrate has a great potential for the solid carbonated food.”

With that in mind, scientists studied which sugars best supported the generation of clathrate hydrate for use in a dessert. Studying sugar is a tough job, but someone’s gotta do it.

“China was the first country in the world to exploit gas hydrates using a horizontal well-drilling technique,” says China’s Ministry of Natural Resources, via the Chinese state press. The technology could represent a way forward for gas lines clogged by clathrates, even if demand for natural gas doesn’t require further commercialization of undersea gas hydrates in the near future.

More development in the field could also mean technical leaps forward in the realm of trapping CO₂.

H/T: Oil Price

Abrupt Warming – How Much And How Fast?

SATURDAY, MAY 13, 2017

https://arctic-news.blogspot.com/2017/05/abrupt-warming-how-much-and-how-fast.html

How much could temperatures rise? As the image shows, a rise of more than 10°C (18°F) could take place, resulting in mass extinction of many species, including humans.

How fast could such a temperature rise eventuate? As above image also shows, such a rise could take place within a few years. The polynomial trend is based on NASA January 2012-February 2017 anomalies from 1951-1980, adjusted by +0.59°C to cater for the rise from 1750 to 1951-1980. The trend points at a 3°C rise in the course of 2018, which would be devastating. Moreover, the rise doesn’t stop there and the trend points at a 10°C rise as early as the year 2021.

Is this polynomial trend the most appropriate one? This has been discussed for years, e.g. at the Controversy Page, and more recently at Which Trend Is best?

The bottom part of above image shows the warming elements that add up to the 10°C (18°F) temperature rise. Figures for five elements may be overestimated (as indicated by the ⇦ symbol) or underestimated (⇨ symbol), while figures in two elements could be either under- or overestimated depending on developments in other elements. Interaction between warming elements is included, i.e. where applicable, figures on the image include interaction based on initial figures and subsequently apportioned over the relevant elements.

A closer look at each of these warming elements further explains why abrupt warming could take place in a matter of years. As far as the first two elements are concerned, i.e. the rise from 1900 and the rise from 1750 to 1900, this has already eventuated. The speed at which further warming elements can strike is depicted in the image below, i.e. the rise could for a large part occur within years and in some cases within days and even immediately.

Assessing the Danger

The danger can be looked at on three dimensions: timescale, probability and severity. On the severity dimension, a 10°C temperature rise is beyond catastrophic, i.e. we’re talking about extinction of species at massive scale, including humans. On the probability dimension, the danger appears to be progressing inevitably toward certainty if no comprehensive and effective action is taken.

In terms of timescale, a 10°C temperature rise could eventuate within a matter of years, which makes the danger imminent, adding further weight to the need to start taking comprehensive and effective action, as described in the Climate Plan.

The Threat

With little or no action taken on global warming, it appears that the Antropocene will lead to extinction of the very human beings after which the era is named, with the Anthropocene possibly running from 1950 to 2021, i.e. a mere 71 years and much too short to constitute an era. In that case a better name for the period would be the Sixth Extiction Event, as also illustrated by the image below.

[ See: Feedbacks in the Arctic and the Extinction page ]

In conclusion, it’s high time that homo sapiens starts acting as genuinely wise modern human beings and commit to comprehensive and effective action as discussed at the Climate Plan.

Further reading

Read more about the threat here. Warming elements are discussed in more detail at the Extinction Page, while specific elements are also discussed in posts, e.g. methane hydrates are discussed at Methane Erupting From Arctic Ocean, decline of the snow and ice cover and associated feedbacks is discussed at Arctic Ocean Feedbacks and less take-up by oceans of CO₂ and heat from the atmosphere is discussed at 10°C or 18°F warmer by 2021? and at the new post High Waves Set To Batter Arctic Ocean.

The situation is dire and calls for comprehensive and effective action as described in the Climate Plan.

Links

• Climate Plan
https://arctic-news.blogspot.com/p/climateplan.html

• Feedbacks
https://arctic-news.blogspot.com/p/feedbacks.html

• Extinction
https://arctic-news.blogspot.com/p/extinction.html

• The Threat
https://arctic-news.blogspot.com/p/threat.html

• Controversy
https://arctic-news.blogspot.com/p/controversy.html

• Which Trend Is best?
https://arctic-news.blogspot.com/2017/03/which-trend-is-best.html

• 10°C or 18°F warmer by 2021?
https://arctic-news.blogspot.com/2017/04/10c-or-18f-warmer-by-2021.html

• Arctic Ocean Feedbacks
https://arctic-news.blogspot.com/2017/01/arctic-ocean-feedbacks.html

• Methane Erupting From Arctic Ocean
https://arctic-news.blogspot.com/2017/03/methane-erupting-from-arctic-ocean-seafloor.html

• High Waves Set To Batter Arctic Ocean
https://arctic-news.blogspot.com/2017/06/high-waves-set-to-batter-arctic-ocean.html

• Warning of mass extinction of species, including humans, within one decade
https://arctic-news.blogspot.com/2017/02/warning-of-mass-extinction-of-species-including-humans-within-one-decade.html

Methane Levels Reach an All-Time High

New NOAA analysis highlights an alarming trend; experts call for curbing pollution from oil and gas wells

Methane Levels Reach an All-Time High
Credit: Richard Hamilton Smith Getty Images

preliminary estimate from NOAA finds that levels of atmospheric methane, a potent heat-trapping gas, have hit an all-time high.

Methane is roughly 80 times more powerful than carbon dioxide, and while it stays in the atmosphere for only around a decade, as opposed to centuries, like CO2, its continued rise poses a major challenge to international climate goals.

“Here we are. It’s 2020, and it’s not only not dropping. It’s not level. In fact, it’s one of the fastest growth rates we’ve seen in the last 20 years,” said Drew Shindell, a climate scientist at Duke University.

To gauge methane levels, scientists regularly gathered samples of air from dozens of sites around the world and analyzed them at NOAA’s Global Monitoring Laboratory in Boulder, Colorado. By comparing measurements, they were able to determine the global average. In 2019, the concentration of atmospheric methane reached nearly 1875 parts per billion, the highest level since record-keeping began in 1983.

Even more troubling, 2019 saw the second-largest single-year leap in two decades. However, this figure may change, as preliminary estimates have trended high, said Ed Dlugokencky, a research chemist at NOAA. The final numbers will likely be unveiled in November after a more detailed analysis.

“We’re still waiting to see what the final number is going to be, and it’s going to be many months before we know that,” Dlugokencky said. “But the fact that methane is increasing means it’s further contributing to climate change.”

Methane emissions primarily come from natural sources, like wetlands, and manmade sources, like farms and oil and gas wells. In wetlands, microbes excrete methane, an issue that humans can do little about. On farms, cows and sheep belch methane—a problem that people can address by raising fewer livestock.

“Eat less beef and less dairy. That’s the most straightforward thing,” Shindell said. “For the sake of our own health, we should be doing that anyway.”

Companies can install recovery equipment that allows them to collect the natural gas that would otherwise seep out. They can then sell this gas, helping to offset the cost of the equipment. By one estimate, oil and gas firms could cut methane pollution by 45 percent at no net cost.

Despite this, many companies are reluctant to pay for recovery equipment. Firms will instead spend their limited capital on a new drilling site, for instance, which will yield a greater return on investment, Shindell said, though practices vary.

Major players—including Chevron, Exxon Mobil, BP and Shell—are taking steps to cap methane pollution, in part, to shore up their public image. However, smaller firms operating on thinner profit margins have less incentive to invest in recovery equipment. And the coronavirus could make the problem worse, as companies facing declining revenues could pay less attention to leaks. For this reason, advocates have called for greater regulation of the oil and gas sector.

“I think that has taken on urgency because in recent years we have witnessed a surge in production of oil and natural gas,” said Devashree Saha, a policy analyst at the World Resources Institute. “Increasing the oversight and regulation of oil and gas production is the only way to go right now.”

“You see the benefits in the first decade or two that you make cuts. You see fewer people dying from heat waves. You see less powerful storms and all of the stuff that comes from climate change,” Shindell said. “As long as we’re still using fossil fuels, we should at least not be leaking out lots and lots of methane.”

Intensity of past methane release measured with new, groundbreaking methods


March 30, 2020
Source:
CAGE – Center for Arctic Gas Hydrate, Climate and Environment
https://www.sciencedaily.com/releases/2020/03/200330093427.htm
Summary:
A novel approach to geochemical measurements helps scientists reconstruct the past intensity of the methane seeps in the Arctic Ocean. Recent studies show that methane emissions fluctuated, strongly, in response to known periods of abrupt climate change at the end of the last glacial cycle.
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FULL STORY

Past records of methane release are crucial for understanding future climate changes. Methane is a potent greenhouse gas, that has had significant impact on climate changes in the geological past.

“Previously, when dating the natural release of methane, we used to measure mostly carbon isotopes. But now we know that carbon isotopes alone can’t tell us the full story of past emissions of this greenhouse gas.” says professor Giuliana Panieri, from CAGE Centre for Arctic Gas Hydrate, Environment and Climate at UiT The Arctic University of Norway.

Professor Panieri is a micropaleontologist and co-author of a new study in Scientific Reports showing a new approach to geochemical measurements.

Geological detective work

Measuring carbon isotopes is a very important method within climate sciences. Carbon, found in all living things, is absorbed over time in a particular fashion by organisms in nature. For instance, carbon found in methane (CH4) in the ocean, is absorbed in the shells of tiny organisms called foraminifera, leaving isotopic clues.

Foraminifera, found in all of the world’s oceans, are excellent carriers of information. They inhabit methane seeps and their shells are preserved as fossils in ocean sediments.

Through some geochemical detective work, and a mass spectrometer, scientists can interpret the amounts of the carbon isotope δ13C in the shells and reconstruct past methane emissions. If δ13C values in the fossilized shells are depleted the methane was present in the environment when the shell was deposited.

Carbon isotope measurements are the most frequently used method, but new technologies make new geochemical components possible to measure, giving climate scientists new tools.

How intense was the release?

The study in Scientific Reports highlights the potential of sulfur isotopic signature (δ34S) in foraminifera, as a novel tool for reconstructing the intensity of CH4 emissions in geological records. This can also, indirectly, help date the release.

“This is the first time that sulfur isotopes are measured in foraminiferal shells from methane seeps. The samples were collected from a well-known site of present-day methane release, Vestnesa Ridge. Here, gas has been seeping into the ocean at least from the Last Glacial Maximum: some 20,000 to 5,000 years ago.” says Panieri.

“How did methane in the sub-seabed respond to previous global warmings? Was it merely bubbling up, or was it released in a constant and abrupt jet, strongly emitted into the water column?”

These questions are important in the provinces of large gas hydrate accumulations, such as Vestnesa Ridge.

Gas hydrate is an icy form of methane, trapped in a cage of frozen water and kept contained in the ocean sediments in low temperatures and under high pressure. However, hydrates are susceptible to melting if these conditions are not met — for example, if the ocean temperature changes due to the warming of the waters. The stability of gas hydrates is under intense investigation because of the possible effects of climate change on gas hydrate dissociation.

“The combination of carbon, oxygen, and sulfur isotopes found in foraminifera allows us to reconstruct the flux of methane released in the geological past. This represents a fundamental advancement in studies of past climate. It offers the opportunity to study the connection between methane seepage, climate, and underlying tectonic processes with a new degree of confidence.” Says Chiara Borrelli, first author of the study and researcher at Department of Earth and Environmental Sciences, University of Rochester, USA.

“Our study shows that there was a strong methane fluctuation at the sampling site, responding to known periods of abrupt cooling and warming, at the end of the last glacial cycle.”

What was the source of methane?

Carbon isotopes can tell scientists whether methane was present in the water column at a certain time. But they cannot tell them if the methane was released from melting hydrates. However, the traces of oxygen isotopic signature δ18O in benthic foraminifera can, as shown in a newly published study by Dessandier et al. in Geo-Marine letters.

“If we have a large amount of δ18O in the foraminiferal shells, we can say that the source of methane is the gas hydrate dissociation,” says Panieri, who also co-authored this paper.

“We found a significant enrichment of δ18Oin all foraminifera samples characterized by depleted δ13C. These results mainly come from the precipitation of authigenic carbonates around the foraminiferal shells, so-called secondary overgrowth. These methane-derived carbonates are characterized by a heavy oxygen isotopic signature. This signature can only be explained by dissociation of gas hydrates because gas hydrates are naturally enriched in 18O due to their ice-like physical properties.” according to Pierre-Antoine Dessandier, a postdoc at CAGE and first author of the study.

Dessandier points out that both δ13C and δ18O clues have to be followed, to decipher the dynamic and the source of the methane release from the Arctic Ocean floor.

Groundbreaking methods from the natural Arctic laboratory

Vestnesa Ridge is a very well-investigated site of methane release, a laboratory for modern-day release of methane from gas hydrates, but also for micropaleontology. It is one of the major sites of research for CAGE.

The exhaustive research on the site has resulted in many scientific breakthroughs in micropaleontology.

“Consider secondary overgrowth on foraminiferal shells: It is a minuscule carbonate deposit. Before CAGE it was considered to be a contaminant in the samples. But new technology opens new doors. We have discovered that the presence of the secondary overgrowth in itself is an indicator of methane release. Something that previously was considered an interference, and caused samples to be thrown out with the thrash, is, in reality, an unknown book, containing enormous amounts of information in itself.” says Panieri.

The new geochemical measurement methods are now added to the toolbox for future micropaleontological research.

“The new isotopic measurements give us a possibility to investigate questions regarding climate change that we today don’t even know that we need to ask. The methods can be applied on both secondary overgrowth and shells themselves, and will be enormously important in future research.”


Story Source:

Materials provided by CAGE – Center for Arctic Gas Hydrate, Climate and Environment. Original written by Maja Sojtaric. Note: Content may be edited for style and length.

Less ice, more methane from northern lakes: A result from global warming

Date:
March 26, 2020
Source:
University of Eastern Finland
Summary:
Shorter and warmer winters lead to an increase in emissions of methane from northern lakes, according to a new study. Longer ice-free periods contribute to increased methane emissions. In Finland, emissions of methane from lakes could go up by as much as 60%.
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Shorter and warmer winters lead to an increase in emissions of methane from northern lakes, according to a new study by scientists in Finland and the US. Longer ice-free periods contribute to increased methane emissions. In Finland, emissions of methane from lakes could go up by as much as 60%.

An international study by scientists from Purdue University in the US, the University of Eastern Finland, the Finnish Environment Institute and the University of Helsinki published in Environmental Research Letters significantly enhances our current knowledge of methane emissions from boreal lakes. The backbone of the study is a large dataset on the distribution and characteristics of lakes and their methane emissions in Finland. Using this dataset and modelling tools, the scientists aimed to find out how methane emissions from northern lakes will change towards the end of this century as a result of global warming.

Lakes account for about 10% of the boreal landscape and are, globally, responsible for approximately 30% of biogenic methane emissions that have been found to increase under changing climate conditions. However, the quantification of this climate-sensitive methane source is fraught with large uncertainty under warming climate conditions. Only a few studies have addressed the mechanisms of climate impact on methane emissions from northern lakes.

The authors estimated that the total current diffusive emission from Finnish lakes is 0.12±0.03 Tg CH4 yr-1 and will increase by 26-59% by the end of this century, depending on the warming scenario used. The study showed that while the warming of lake water and sediments plays a vital role, the increase in the length of the ice-free period is a key factor increasing methane emissions in the future.

“The boreal lakes remain a significant methane source under the warming climate within this century, and the increase in methane emissions depends on latitude: the increase is greater from the lower latitude northern lakes,” Dr Narasinha Shurpali from the University of Eastern Finland and Dr Pirkko Kortelainen from the Finnish Environment Institute point out.

“The study shows the importance of co-operation between modellers and experimentalists. Here the representative dataset on lakes and their methane emissions was produced by the Finnish Environment Institute and the universities, enabling biogeochemical modelling to estimate the present and future methane emissions from lakes,” Professor Pertti Martikainen from the University of Eastern Finland notes.