New study finds world’s strongest ocean current speeding up

Researchers say “robust acceleration” in the Antarctic Circumpolar Current has been largely driven by ocean warming tied to human activity.ByBrooke Migdon | Dec. 6, 2021 seconds of 15 secondsVolume 20% 

Story at a glance

  • The world’s strongest ocean current, the Antarctic Circumpolar Current, is speeding up, according to new research, mostly because of rising ocean temperatures.
  • The ACC carries water around the globe, pushing more water than any other ocean current.
  • It’s not entirely clear what accelerating currents mean for the ocean, but additional research has suggested it will likely alter waters’ heat distribution and impact the way in which nutrients are carried in oceans across the globe.

Earth’s strongest ocean current is getting faster, new research has found, and it’s largely because of humans.

The study, published late last month in the journal Nature Climate Change, concluded that “robust acceleration” in the Antarctic Circumpolar Current was driven mostly by human activity, which has caused ocean temperatures to climb. When the gap in temperatures between hot and cold water widens, the currents that border them pick up speed.

“Anthropogenic ocean warming is the dominant driver,” researchers at the University of California San Diego and the University of California Riverside wrote. The current is also heavily influenced by wind.

The ACC separates the Southern Ocean from the Atlantic, Pacific and Indian Oceans and carries water clockwise around the globe. It pushes more water than any other current and is the only ocean current that is not blocked by land masses, though Antarctica is surrounded by it.

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Researchers in the study used satellite data on the height of the sea surface and data collected by Argo floats, data-gathering robotic instruments in oceans all over the world used to track the temperature and salinity of ocean water.

Limitations of prior research have masked the ocean’s “dynamic” response to warming before now, researchers wrote, and, because the region absorbs much of the atmospheric heat generated by humans, the current should continue to quicken as the planet warms.

Scientists are still working to understand the knock-on effects of accelerating currents, but it’s believed they will alter oceans’ heat distribution, affecting marine life receiving mostly warmer waters. Faster circulation will also change how nutrients are carried in oceans around the world.

Researchers earlier this year discovered the ACC once sped up between 115,000 and 130,000 years ago during the last interglacial period, which likely caused massive weather disruptions and lowered the ocean’s ability to absorb carbon dioxide.

The world’s biggest carbon-removal plant just opened. In a year, it’ll negate just 3 seconds’ worth of global emissions.

Aylin Woodward Sep 25, 2021, 4:06 AM

climeworks carbon capture plant orca iceland
“Orca,” Climeworks’ new facility in Iceland, can capture 4,000 tons of carbon dioxide per year. 
  • The world’s biggest carbon-capture plant — which sucks carbon dioxide out of the air — just opened.
  • A UN report says carbon capture technology is necessary if the world wants to be carbon neutral by 2050.
  • But many experts think the tech is too expensive and not scalable in the next few decades.

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Framed by a backdrop of volcanoes, a semi-circle of gigantic fans in Iceland are sucking in air, super-heating it, then filtering out the carbon dioxide.

This carbon capture and storage facility, named Orca, turned on two weeks ago after more than 18 months of construction. The fans are embedded in shipping container-sized boxes, and once the carbon dioxide is separated, it gets mixed with water then travels through snaking, fat tubes deep underground, where the carbon cools and solidifies.

Through this process, Orca can trap and sequester 4,000 metric tons of carbon dioxide per year — making it the largest facility of its kind in the world (though there are currently only two running).

“Think of it like a vacuum cleaner for the atmosphere,” Julio Friedmann, an energy policy researcher at Columbia University who attended the plant’s ribbon-cutting ceremony, told Insider. “Nothing else can do what this tech does.”

According to the latest report from the United Nations Intergovernmental Panel on Climate Change (IPCC), carbon capture and storage is a necessary part of our best-case climate scenarios. But currently, facilities like Orca only negate a sliver of global emissions.

Climate scientist Peter Kalmus has done the math: “If it works, in one year it will capture three seconds worth of humanity’s CO2 emissions,” he wrote on Twitter.


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Put another way, Kalmus told Insider, “at any given moment, it will capture one 10-millionth of humanity’s current emissions.”

“It’s remarkable to me it is being considered as part of those plans,” he said of the IPCC report.

‘Probably the most expensive solution’

carbon capture plant texasEquipment used to capture carbon dioxide at a coal-fired power plant owned by NRG Energy in Thompsons, Texas, on January 9, 2017. Ernest Scheyder/Reuters

The Orca facility works differently than the carbon-capture technologies built into some power plants, steel mills, and industrial facilities. Those collect the carbon produced in the manufacturing process before it enters the air. It can then be converted into materials like concrete or stored underground.

More than 20 facilities worldwide currently do this, most of which are in the US. But that simply prevents more carbon from accumulating in the atmosphere. Orca, by contrast, is an attempt to deal with the greenhouse gas that’s already up there.

This technology, known as direct air capture, is in its infancy. The Swiss company Climeworks, which built Orca, has the only operational game in town; its other plant is in Switzerland. Before that, the technology had only been used on a small scale in spacecraft and submarines.

Two other plants are in planning phases: The Canadian company Carbon Engineering, which is backed by Bill Gates, started designing a similar facility in northeastern Scotland three months ago. It also plans to start construction on a a plant in Texas next year. Each of those facilities could remove up to 25 times more carbon per year than Orca.


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climeworks carbon capture plant switzerland
A Climeworks facility for capturing carbon dioxide atop the roof of a waste incinerating plant in Hinwil, Switzerland, July 18, 2017. 

But as with many emerging technologies, direct air capture is expensive. Christoph Gebald, Climeworks’ co-founder, told the Washington Post that it costs at least $600 to capture one metric ton of carbon dioxide, since super-heating the air takes a lot of energy.

That cost would need to drop to one-fourth its current level to bring it in line with technologies like wind and solar in terms of their carbon abatement — the degree to which they reduce emissions. To sell carbon commercially — like to beverage companies making fizzy drinks — the price would have to get even lower, probably between $65 and $110 per metric ton.

Friedmann thinks a drop to below $200 is likely by 2030, and a drop to $100 two decades after that. By that point, he said, the market for carbon removal market — companies paying to abate their emissions — will have grown significantly.

But even at that $100 price, removing all of humanity’s annual carbon emissions would cost more than $5 trillion per year, according to Gates’ book, “How to Avoid a Climate Disaster.” That would require 50,000 Orca plants.

“It’s probably the most expensive solution,” Gates wrote.

Icebergs near Ilulissat, Greenland. Climate change is having a profound effect in Greenland with glaciers and the Greenland ice cap retreating.
Icebergs melting near Ilulissat, Greenland. 

There’s also the question of timing. The IPCC report says that without capturing significant amounts of carbon over the next 30 years, it will be impossible to get humanity to net-zero emissions by 2050 — and, consequently, to limit warming to 1.5 degrees Celsius.

But Mathew Barlow, a climate scientist at the University of Massachusetts, Lowell, said three decades isn’t enough for the technology to be deployed widely.

“There’s no possible way for it to scale up on that timescale,” Barlow, who contributed to the IPCC report, told Insider. “We’re at the point where you need to get the tech off the shelves, not be building it out.”

‘Fossil-fuel companies love carbon capture’

Plants like Orca do, however, out-perform their natural counterparts — trees.

“The Orca facility does the work of 200,000 trees in 1,000 times less space,” Friedmann said.

What’s more, once a facility like this stores its carbon, it’s locked away. If trees burn, the carbon they’ve absorbed gets released. 

Reforestation in Leiria Portugal 2018
A reforestation project in Leiria, Portugal in 2018. 

But trees capture carbon at a much lower cost of $50 per metric ton.

Kalmus thinks carbon capture ultimately distracts the world from other solutions that would make a bigger dent in emissions, like investment in renewables and regulations targeting the fossil-fuel industry.

“Fossil-fuel companies love carbon capture because it really does let them off the hook,” he said.

Friedmann, though, thinks it’s possible to expand carbon-capture infrastructure enough to make a difference. If the Senate’s infrastructure bill passes in the House, it would allocate $3.5 billion toward direct air capture facilities in the US. Elon Musk also announced this year that he’s funding a $100 million carbon-capture contest.

“We now know that we can do it,” Friedmann said. “Now we’re just haggling over price and literally asking how much we’re willing to pay to save the Earth.”


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NOW WATCH: This massive wall of fans will suck carbon dioxide straight out of the air seconds of 7 minutes, 21 secondsVolume 0% More: Climate ChangeGlobal WarmingCarbon EmissionsFossil Fuels

Carbon capture and “dimming” the sun pose dilemmas for climate

Carbon capture and “dimming” the sun pose dilemmas for climate (

Jeff Berardelli  4 hrs ago

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The climate crisis is arguably the biggest challenge humanity has ever faced, and to limit warming to manageable levels, time is our biggest opponent. While the transition from fossil fuels to cleaner renewable energy is now gaining steam, the pace is simply not fast enough to head off the harmful impacts that are already being felt throughout the world.a sunset over some water: Operations At A Carbon Engineering Direct Air Capture Pilot Facility© James MacDonald/Bloomberg via Getty Images Operations At A Carbon Engineering Direct Air Capture Pilot Facility

The Intergovernmental Panel on Climate Change (IPCC) “Special Report: Global Warming of 1.5ºC” — the international community’s benchmark guide to averting climate disaster — says to reach the goal of staying below 1.5ºC of warming requires “rapid and far-reaching transitions” in our energy, industrial and other systems that would be “unprecedented in scale.” In other words, the task is herculean. 

So, many experts say drastic times call for drastic measures, arguing that technology like climate geoengineering should be part of the solution toolkit. Proponents say that while switching to renewable energy, driving electric vehicles and restoring forests can get us far, that’s simply not enough. The IPCC agrees, and cites one specific type of geoengineering — carbon capture and sequestration — as a necessary part of the suite of solutions.PauseCurrent Time 0:38/Duration 5:58Loaded: 22.36%Unmute0LOCaptionsFullscreenGeoengineering: A controversial solution that could help fight climate changeClick to expand

While carbon capture — a process of trapping, compressing and then storing away harmful emissions to keep them out of the atmosphere — has its share of detractors, the climate community generally accepts that it will be necessary, though the extent to which it can and should be used is hotly debated.

But that debate pales in comparison to the controversy provoked by another proposed type of geoengineering known as Solar Radiation Management, in which humans would artificially dim the sun. That idea is loaded with compelling physical and ethical considerations which will be explored below.

Carbon capture

Since the Industrial Revolution, the burning of fossil fuels has released 1.6 trillion tons of heat-trapping greenhouse gases into the atmosphere. Carbon dioxide (CO2) has increased by 50% — at a pace 100 times faster than it naturally should. As a result, our planet is now warming 10 times faster than it has in 65 million years. The scale and speed is unprecedented.

Despite advances in clean energy like wind and solar, the world still gets 80% of its energy from fossil fuels. Because it is integrated into almost every nook and cranny of modern life, the challenge of eliminating carbon from our energy system is monumental. And even if humanity can significantly slow or even stop emitting carbon pollution, carbon dioxide will remain in the atmosphere for hundreds or even thousands of years. The only way to reduce greenhouse gas concentrations is to pull the carbon back out of the atmosphere. 

In order to do that, there are natural solutions like forest restoration as well as technical solutions like carbon capture systems.

2017 research paper, led by the Nature Conservancy, found that natural climate solutions like restoring forests, wetlands and grasslands can, in a best-case scenario, provide 37% of the CO2 mitigation needed to keep humanity below the upper goal (2ºC of warming) of the Paris Agreement. That’s significant, but not enough. 

Chad Frischmann, the senior director of research and technology at Project Drawdown, a climate solutions organization, prefers if society concentrates on developing ways to get nature to do the work. 

“Overall, these natural forms of ‘carbon capture’ are tried, true and cost effective. More importantly, they have a ton of cascading benefits to agricultural productivity, biodiversity, and the health of the planet,” he said.

But carbon capture specialists like Dr. Julio Friedmann, a global energy policy expert from Columbia University — known as @CarbonWrangler on Twitter — believe technological solutions should have a bigger role to play because even if we shift to clean energy there are certain industrial processes, like cement and steel making, that cannot easily be decarbonized.

As is clear from his Twitter handle, Friedmann is bullish on carbon removal — not as a replacement for other solutions, but as a complement to them. 

“CO2 removal is one mitigation strategy. It is a mitigation strategy like efficiency, renewables, electric vehicles. It is just one of the many things that we will do,” he said. “But if we do everything we know how to do today there’s always this fat residual 10 billion tons a year that we have no solutions for.”

Carbon capture — often referred to as CCUS, for carbon capture, utilization and storage — is an industrial process by which carbon dioxide is absorbed during power generation and industrial processes and stored away, typically underground, sometimes utilized for enhanced oil recovery or used in certain manufactured goods. 

Globally, there are about 50 large-scale CCUS plants, including 10 currently operating in the U.S. a large air plane on display: A pipe installed as part of the Petra Nova Carbon Capture Project carries carbon dioxide captured from the emissions of the NRG Energy Inc. WA Parish generating station in Thompsons, Texas, in 2017. The project, a joint venture between NRG Energy and JX Nippon Oil & Gas Exploration Corp., reportedly captures and repurposes more than 90% of its own CO2 emissions. / Credit: Luke Sharrett/Bloomberg via Getty Images© Provided by CBS News A pipe installed as part of the Petra Nova Carbon Capture Project carries carbon dioxide captured from the emissions of the NRG Energy Inc. WA Parish generating station in Thompsons, Texas, in 2017. The project, a joint venture between NRG Energy and JX Nippon Oil & Gas Exploration Corp., reportedly captures and repurposes more than 90% of its own CO2 emissions. / Credit: Luke Sharrett/Bloomberg via Getty Images

A less common but growing method is called direct air capture (DAC), in which carbon dioxide is sucked right out of the air through the use of large fans. There are currently only 15 DAC facilities worldwide which capture only 9,000 tons of carbon dioxide a year. Some larger facilities are planned. The Swiss company Climeworks is building a DAC plant in Iceland capable of capturing 4,000 tons, and the American petroleum giant Occidental plans a much more ambitious facility in the West Texas Permian Basin which it says will capture 1 million tons of CO2 a year.

Collectively all these CCUS and DAC facilities have the capacity to capture about 40 million tons of carbon dioxide yearly. It sounds like a lot, until you consider that each year humans emit almost 40 billion tons of carbon dioxide into the atmosphere —1,000 times more than we can capture — to say nothing about all the CO2 that is already up there as a result of the Industrial Revolution.

To put it bluntly, critics say CCUS and DAC are not ready for prime-time and may never be. The processes are very expensive, they consume copious amounts of energy themselves — often, ironically, produced by burning fossil fuels — and their capacity is just a tiny fraction of what’s needed.

Frischmann said, “They will never scale to the level necessary to offset fossil fuel emissions, and will take 20 years of 20% annual growth to even start making a dent in the atmosphere. Highly unlikely rate of growth.”

He’s also concerned about the moral hazard of promoting carbon capture as a solution, because he says these “false silver bullets” mean emitters can keep emitting with the promise that technology will suck up all their pollution. “Attention to them now allows fossil fuel companies, and their cronies, to continue business-as-usual with the promise of a Band-Aid that is not materializing anytime soon,” Frischmann said.

But Friedmann disagrees. He believes good policies can help carbon capture scale up quickly. 

“It’s not a technology challenge, it’s a finance challenge,” he said. “It’s helpful to think about these things like solar in 2002. Solar electricity in 2002 was expensive, not mass produced. And then there was this set of policy and innovation pushes that really dropped the price and helped commercialization.”

He also feels that mopping up our mess is a moral responsibility. 

“If you accept that we should remove CO2 from the air and oceans, it is essentially a way of addressing prior wrongs. It’s a way of the Global North announcing its intentions to clean up its mess and say we are going to do this so the Global South doesn’t have to.”a group of people standing in front of a building: Technicians inspect the direct air capture system at the Carbon Engineering Ltd. pilot facility in Squamish, British Columbia, Canada, on Nov. 4, 2019. / Credit: James MacDonald/Bloomberg via Getty Images© Provided by CBS News Technicians inspect the direct air capture system at the Carbon Engineering Ltd. pilot facility in Squamish, British Columbia, Canada, on Nov. 4, 2019. / Credit: James MacDonald/Bloomberg via Getty Images

Peter Kalmus (@ClimateHuman), a NASA climate scientist, says he supports the concept of carbon capture and thinks we should keep researching it, but he is “extremely skeptical it will ever be possible or helpful.” He thinks it should not be included in planning until we know it can be done at scale. 

Kalmus puts it colorfully: “I feel the IPCC stepped way out of bounds in normalizing it in greenhouse gas budgets and scenarios. They may as well have included genies, fairies, and pixies in their scenarios.” 

Kalmus shares a concern with many others in the climate community that focusing on carbon capture will distract us from the real work of getting off fossil fuels.

He said, “The most compelling ‘con’ to me is that it will be used by politicians, decision-makers, and the public to reduce the urgency and delay timescales for addressing what is surely the greatest emergency facing humanity.”

But clearly the two arguments are not mutually exclusive: carbon capture can both be used as a delay tactic and also be a necessary part of the solution. 

President Biden’s ambitious climate agenda aims to bolster the U.S. carbon capture capacity, not only to clean up the environment but also to create jobs. His $2 trillion infrastructure plan includes funding for carbon recapture plants. This is a rare area of agreement for Democrats and Republicans and may be a necessary inclusion to help garner support across the aisle. It’s even won support from the United Mine Workers of America, which backed incentives for using carbon capture technology along with measures to protect jobs in coal country.

Solar geoengineering

If the idea of artificially dimming the sun to minimize global warming seems like science fiction, you wouldn’t be alone in that opinion. It is certainly fraught with potential dangers and unknowns. But the concept is actually rather simple technologically, and relatively inexpensive. The challenges are not so much technical or financial, they are political and ethical.

Proponents like Bill Gates say solar geoengineering could buy humanity time to transition over to renewable energy. Opponents argue there are a multitude of concerns about the potential consequences.

Solar geoengineering proposals go by various names, including Solar Radiation Management (SRM) and Stratospheric Aerosol Intervention (SAI).

The idea is to fly specialized planes into the stratosphere, more than 50,000 feet above Earth’s surface, and unload small aerosol particles (like sulfates) which would block some of the sunlight from reaching the Earth. Because atmospheric winds are all connected, the suspended particles would circulate the globe. Less sun equals less heating. Theoretically, the amount of cooling could be controlled by managing the amount and distribution of aerosols the planes deliver. As long as the particles are up there, the cooling would continue.

There is also a less talked-about option called Marine Cloud Brightening. It’s somewhat similar in that particles are injected, but this time into clouds to make them brighter, whiter and more able to reflect sunlight back into space before it heats the Earth. Proposals suggest spraying sea salt aerosols from vessels into marine clouds. Those particles would act as condensation nuclei allowing more cloud droplets to form, blocking more sun. Here the impacts here would be more regional, not global. 

Both types of solar geoengineering are explained below, in an illustration from the Union of Concerned Scientists. / Credit: Union of Concerned Scientists© Provided by CBS News / Credit: Union of Concerned Scientists

Scientists know SAI could lower temperatures because a natural version of it is on display for all to see and measure when big volcanoes, like Mout Pinatubo in the Philippines, erupt and spew sulfates high up into the stratosphere. 

In 2001, Pinatubo injected about 15 million tons of sulfur dioxide into the stratosphere, where it formed a hazy layer of aerosol particles composed primarily of sulfuric acid droplets. This blocked enough sunlight to reduce the planet’s temperature by 1ºF over the course of 1 to 2 years.a group of clouds in the sky: A giant mushroom cloud of steam and ash exploding out of Mount Pinatubo volcano during an eruption on June 12, 1991. / Credit: ARLAN NAEG/AFP via Getty Images© Provided by CBS News A giant mushroom cloud of steam and ash exploding out of Mount Pinatubo volcano during an eruption on June 12, 1991. / Credit: ARLAN NAEG/AFP via Getty Images

“The technical challenges for stratospheric aerosol geoengineering are not great, all that is needed is a new, high-altitude jet that could carry tons of material into the lower stratosphere, about 60,000 feet up,” explains Peter Irvine, a professor of solar geoengineering at University College London.  

Specialized planes would be needed because the air is much thinner at that high altitude. Irvine believes it’s a cost-effective option to consider given the severity of the crisis facing the planet.

“Developing and running a fleet of such aircraft would cost a few billion dollars per year initially, which is small compared to the projected damages of climate change or to the costs of decarbonizing the economy,” he said.

A 2018 paper estimates the upfront cost for development of one such aircraft would be $2 to $3 billion, and maintaining a fleet of planes making 4,000 worldwide missions per year would cost around $2 to $2.5 billion per year over the first 15 years.

Frischmann says it’s the affordability that scares him.

“It is cheap, and this is scary. There are any number of billionaires, corporations or small states with the wealth to inject enough sulfate into the stratosphere to cause irreparable damage. Chilling thought,” he said.

The damage that might be caused by tampering with the atmosphere is debatable and unknown because there simply hasn’t been much real-world research done. That’s partly because any atmospheric modification, or even the consideration of it, is highly controversial. 

A major concern among many climate scientists is the chance of unintended consequences from artificially cooling the Earth with aerosols. Could it cause floods in one nation and droughts in another? Will it weaken the ozone layer? Will it hurt species or ecosystems? Could it be used unilaterally as a weapon by one nation to inflict climate damage on another? Some of these hypotheticals may be more likely than others, but these are questions that can only be answered by research.

Its ability to raise alarm was on display a few weeks ago. A very small research project called SCoPEx, by a group of Harvard researchers, which was scheduled for this summer, was just postponed until at least 2022. To illustrate how divisive the concept is, the team wasn’t even spraying any aerosols — just testing equipment. Regardless, Swedish environmental organizations and the Indigenous Saami Council sent a letter demanding the project be canceled, calling the plan a real moral hazard and saying the technology entails risks of catastrophic consequences. The Harvard advisory committee put it on hold, pending further societal engagement.

While Irvine is bullish on SIA’s “potential to reduce the risks of climate change if used as a complement to emissions cuts,” he is quick to point out that a much better understanding is needed: “We don’t know enough about its potential, limits and risks to make recommendations on whether or not to deploy it. Research is needed to better understand its potential physical consequences, as well as to understand the broader social and political challenges it poses.”

In 2019, the U.S. government allotted $4 million for stratospheric monitoring and research efforts. The program includes assessments of solar climate interventions such as proposals to inject material into the stratosphere.a factory with a sunset in the background: The sun rises over an oil field over the Monterey Shale formation where gas and oil extraction using hydraulic fracturing, or fracking, is taking place on March 24, 2014 near Lost Hills, California. / Credit: David McNew / Getty Images© Provided by CBS News The sun rises over an oil field over the Monterey Shale formation where gas and oil extraction using hydraulic fracturing, or fracking, is taking place on March 24, 2014 near Lost Hills, California. / Credit: David McNew / Getty Images

A year ago, Irvine and Dr. David Keith, another well-known expert in solar geoengineering, published a paper looking into the effectiveness and potential side effects of SAI. In a geoengineering model study, the team found that halving warming with stratospheric aerosol geoengineering could potentially reduce key climate hazards and would have limited regional side effects. But a limited model study is not nearly enough to base these monumental decisions on.

Recently, solar geoengineering supporters got a boost from a powerful scientific organization. Given the urgency of the risks posed by climate change, the National Academy of Sciences recommended that the U.S. government should cautiously pursue a research program for solar geoengineering, with funding in the $100 to $200 million range over 5 years. 

But even if solar geoengineering worked to cool temperatures, it would do nothing for the problem of ocean acidification, because it does not address the root cause of the warming — the carbon dioxide which traps heat and dissolves in the ocean to make waters more acidic.

For all these reasons, many in the climate community believe the cons outweigh the potential pros. 

“In short, do not try to fix a global, catastrophic problem with a Band-Aid that no one knows will work as intended, or knows what long-term unintended damage can be done to the planet,” said Frischmann. 

Kalmus sees the value in researching solar geoengineering, but says the fact that we are even contemplating it evokes visions of a dystopian future. He goes further by discussing what is likely the most risky aspect of SAI. 

“Solar geoengineering has an even darker aspect which is that the moment society stopped doing it, for whatever reason, there would be a rapid spike in global mean temperature, which is an extraordinarily dangerous prospect,” he said. 

In other words, if the world used SAI to hold down temperatures for 30 years, and then stopped, almost immediately temperatures would spike the whole 30 years worth of warming in a year or two — with possibly devastating consequences for ecosystems and species that could not immediately adapt.

“It is a last resort lever to be pulled under the most dire circumstances for life on the planet. There is not a scenario where I see this as needed,” Frischmann urges. As an expert in solutions, he points instead to a more holistic set of changes we could make to energy use, industry, transportation, agriculture and other sectors that are supported by research

Kalmus sees resorting to extreme geoengineering solutions as lazy and selfish. 

“Saying either ‘we’ll figure out and do carbon capture later this century’ or ‘we’ll cool the planet with aerosols’ is negligently irresponsible, and basically says, ‘We old people can keep consuming and polluting, we’ll force our kids to pay the price.’ It’s intergenerational genocide.”

Carbon dioxide in atmosphere has spiked to record-setting new level

Observatory data confirms a returned trend of increasing atmospheric carbon dioxide levels.ByAlexandra Kelley | April 6, 2021 of 00:55Volume 20%Next Up 

Story at a glance

  • As travel returns worldwide, carbon dioxide levels are increasing.
  • Carbon dioxide and other greenhouse gases are key contributors to climate change.

One of the U.S.’s premier observatories for measuring carbon dioxide emissions released into the atmosphere reported a record-breaking figure on April 3, noting a total of 421.21 particulate matter (ppm) of carbon dioxide in the Earth’s atmosphere — the highest daily average ever recorded.

Based on data collected at the Mauna Loa laboratory in Hawaii, the peak comes after relatively low readings throughout March and early April, aside from a single uptick recorded between March 19 to 21.

Notably, however, when observing annual trends, this record-breaking volume represents a return to pre-pandemic levels. 

Carbon dioxide emissions have gradually increased since hitting record low levels during September and October of 2020, in the middle of the ongoing COVID-19 pandemic. This is broadly due to less travel by car, plane and other modes of transportation during lockdowns. 





Prior to these record drops, emissions had posted steady declines since May 2020, with decreasing carbon dioxide levels occurring monthly from June to September of 2020.

The holiday months of November and December of 2020 saw burgeoning increases as a travel boom gave way to another surge of COVID-19 infections. This trend of rising carbon dioxide levels continues to persist.

A silver lining of the mass economic shutdowns spurred by the COVID-19 pandemic were widespread decreases in carbon dioxide and other greenhouse gas emissions, the main factors in anthropomorphic climate change.

As travel begins to resume, levels of carbon dioxide in the atmosphere are also increasing to comparable pre-pandemic levels. 

Since the 1960s, per Mauna Loa station data, atmospheric carbon dioxide has increased dramatically each decade.

Environmental advocates have underscored the need for sustainable policies of a government level to reduce the effects of climate change. 

One of Earth’s giant carbon sinks may have been overestimated – study

The potential of soils to slow climate change by soaking up carbon may be less than previously thought

Grassland in RussiaGrassland in Russia
Grassland in Russia. The study suggests that plans to plant trees is such areas to combat climate change may be counterproductive. Photograph: Valery Matytsin/TASS

Damian Carrington Environment editor@dpcarringtonWed 24 Mar 2021 12.00 EDT


The storage potential of one of the Earth’s biggest carbon sinks – soils – may have been overestimated, research shows. This could mean ecosystems on land soaking up less of humanity’s emissions than expected, and more rapid global heating.

Soils and the plants that grow in them absorb about a third of the carbon emissions that drive the climate crisis, partly limiting the impact of fossil-fuel burning. Rising carbon dioxide levels in the atmosphere can increase plant growth and, until now, it was assumed carbon storage in soils would increase too.

But the study, based on over 100 experiments, found the opposite. When plant growth increases, soil carbon does not. The finding is significant because the amount of organic carbon stored in soils is about three times that in living plants and double that in the atmosphere. Soils can also store carbon for centuries, whereas plants and trees rot quickly after they die.

It is not yet known how big the effect of lower carbon storage in soils might be on the speed of climate change, and experts cautioned that other impacts of the climate emergency such as drought would also affect how well plants and soils store carbon.

“We found that when rising CO2 increases plant growth, there is a decrease in soil carbon storage. That’s a very important conclusion,” said César Terrer, who led the research while at Stanford University in the US. He said that if soils do absorb less in future, “the speed of global warming could be higher”.

Terrier said soils, plants and trees were important for carbon levels, but that ending the burning of fossil fuels remains essential. “If we really want to stop global warming, we need to stop emissions, because ecosystems only take up a fraction of all the CO2 emissions,” he said.

The study, published in the journal Nature, analysed more than 100 experiments from across the world in which soils, plants and trees were exposed to higher CO2 levels than in today’s atmosphere. The biomass growing in forests rose by 23% in experiments where the CO2 level used was double pre-industrial atmospheric levels. It is 50% higher today. But the forest soils did not store any more organic carbon at all.Advertisement

It was thought that biomass and soil carbon would increase in tandem, as more plant biomass falls to the ground and turns into organic matter. But increased plant and tree growth requires more nutrients from the soil, which may explain the new finding, the scientists said. Extracting the extra nutrients requires the plants to increase the symbiotic microbial activity in their roots, which then releases CO2 to the atmosphere that might otherwise have remained locked in the soil.

The researchers found that in grasslands, elevated CO2 led to 9% plant growth – less than forests – but soil carbon rose by 8%. Terrier said there has been a lot of discussion about tree planting as a way to tackle the climate crisis. “What I found very concerning in that debate is that people were suggesting planting trees in natural grasslands, savannah, and tundra,” he said. “I think that would be a terrible mistake because, as our results imply, there is a very large potential to increase soil carbon storage in grasslands.”

Prof Simon Lewis, at University College London, who was not part of the research team, said: “Given that the land absorbs 30% of the carbon emitted from fossil fuels and deforestation, understanding if that will change in the future matters.”

He said the change would be determined by the balance between rising CO2 boosting plant growth and the negative effects of climate change itself, including drought, heatwaves and fires. The evidence to date suggests the biggest change will be the negative effects of global heating on ecosystems, he said.

Prof Pete Smith at the University of Aberdeen said: “The combined effect of CO2 on plants and soils and on climate change is what matters in terms of the real world response.”

Insatiable demand for cannabis has created a giant carbon footprint

MARCH 8, 2021

by Colorado State University

Insatiable demand for cannabis has created a giant carbon footprint
The life cycle greenhouse gas emissions from indoor cannabis cultivation modeled across the U.S. Credit: Hailey Summers/Colorado State University

It’s no secret that the United States’ $13 billion cannabis industry is big business. Less obvious to many is the environmental toll this booming business is taking, in the form of greenhouse gas emissions from commercial, mostly indoor production.

A new study by Colorado State University researchers provides the most detailed accounting to date of the industry’s carbon footprint, a sum around which there is only limited understanding. What is clear, though, is that consumer demand for cannabis is insatiable and shows no signs of stopping as more states sign on to legalization.

The study, published in Nature Sustainability, was led by graduate student Hailey Summers, whose advisor, Jason Quinn, is an associate professor in the Department of Mechanical Engineering. Summers, Quinn and Evan Sproul, a research scientist in mechanical engineering, performed a life-cycle assessment of indoor cannabis operations across the U.S., analyzing the energy and materials required to grow the product, and tallying corresponding greenhouse gas emissions.

They found that greenhouse gas emissions from cannabis production are largely attributed to electricity production and natural gas consumption from indoor environmental controls, high-intensity grow lights, and supplies of carbon dioxide for accelerated plant growth.

“We knew the emissions were going to be large, but because they hadn’t been fully quantified previously, we identified this as a big research opportunity space,” Summers said. “We just wanted to run with it.”

The CSU group’s efforts update previous work by Lawrence Berkeley National Laboratory researchers, which quantified small-scale grow operations in California and predated the cascade of state-by-state legalization since Colorado was first to legalize in 2012. To date, 36 states have legalized medical use of cannabis, and 15 have legalized recreational use.

Mapping variable emissions

The CSU team surmised there would be substantial variability in emissions depending on where the product was being grown, due to climate as well as electric grid emissions. Their recently published work captures the potential cross-country spread of large commercial warehouses for growing cannabis, and it models emissions for several high-growth locations around the country. Their results include a map that shows relative emissions anywhere in the U.S., as defined as emissions per kilogram of cannabis flower. They’ve also developed a GIS map that allows users to enter a county name and find local emissions estimates.×280&!1&btvi=1&fsb=1&xpc=wmKdTPVEMg&p=https%3A//

Their research shows that U.S. indoor cannabis cultivation results in life-cycle greenhouse gas emissions of between 2,283 and 5,184 kilograms of carbon dioxide per kilogram of dried flower. Compare that to emissions from electricity use in outdoor and greenhouse cannabis growth, which is 22.7 and 326.6 kilograms of carbon dioxide, respectively, according to the New Frontier Data 2018 Cannabis Energy Report. Those outdoor and greenhouse numbers only consider electricity, while the CSU researchers’ estimate is more comprehensive, but the comparison still highlights the enormously larger footprint of indoor grow operations.

The researchers were surprised to find that heating, ventilation and air conditioning systems held the largest energy demand, with numbers fluctuating depending on the local climate—whether in Florida, which requires excessive dehumidifying, or Colorado, where heating is more important.

The high energy consumption of cannabis is due in part to how the product is regulated, Quinn said. In Colorado, many grow operations are required to be in close proximity to retail storefronts, and this has caused an explosion of energy-hungry indoor warehouses in urban areas like Denver. According to a report from the Denver Department of Public Health and Environment, electricity use from cannabis cultivation and other products grew from 1% to 4% of Denver’s total electricity consumption between 2013 and 2018.

The team is seeking more funding for continuing their modeling work, with hopes of extending it to a comparison between indoor and potential outdoor growth operations. Ultimately, they would like to help the industry tackle environmental concerns while legal cannabis is still relatively new in the U.S.

“We would like to try and improve environmental impacts before they have become built into the way of doing business,” Sproul said.

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Warming already baked in will blow past climate goals, study finds

A study in the journal Nature Climate Change figures the carbon pollution already put in the air will push global temperatures to about 2.3 degrees Celsius.

Smoke billows from the Jeffrey Energy Center coal-fired power plant on Sept. 12, 2020, near Emmet, Kan.

Smoke billows from the Jeffrey Energy Center coal-fired power plant on Sept. 12, 2020, near Emmet, Kan.Charlie Riedel / AP fileJan. 5, 2021, 6:15 AM PST / Updated Jan. 5, 2021, 6:17 AM PSTBy Associated Press

The amount of baked-in global warming, from carbon pollution already in the air, is enough to blow past international agreed upon goals to limit climate change, a new study finds.

But it’s not game over because, while that amount of warming may be inevitable, it can be delayed for centuries if the world quickly stops emitting extra greenhouse gases from the burning of coal, oil and natural gas, the study’s authors say.

For decades, scientists have talked about so-called “committed warming” or the increase in future temperature based on past carbon dioxide emissions that stay in the atmosphere for well over a century. It’s like the distance a speeding car travels after the brakes are applied.

But Monday’s study in the journal Nature Climate Change calculates that a bit differently and now figures the carbon pollution already put in the air will push global temperatures to about 2.3 degrees Celsius (4.1 degrees Fahrenheit) of warming since pre-industrial times.

Previous estimates, including those accepted by international science panels, were about a degree Celsius (1.8 degrees Fahrenheit) less than that amount of committed warming.

International climate agreements set goals of limiting warming to 2 degrees Celsius (3.6 degrees Fahrenheit) since pre-industrial times, with the more ambitious goal of limiting it to 1.5 degrees Celsius (2.7 degrees Fahrenheit) added in Paris in 2015. The world has already warmed about 1.1 degrees Celsius (2 degrees Fahrenheit).

“You’ve got some … global warming inertia that’s going to cause the climate system to keep warming, and that’s essentially what we’re calculating,” said study co-author Andrew Dessler, a climate scientist at Texas A&M University. “Think about the climate system like the Titanic. It’s hard to turn the ship when you see the icebergs.”

Dessler and colleagues at the Lawrence Livermore National Lab and Nanjing University in China calculated committed warming to take into account that the world has warmed at different rates in different places and that places that haven’t warmed as fast are destined to catch up.


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Places such as the Southern Ocean, surrounding Antarctica are a bit cooler, and that difference creates low-lying clouds that reflect more sun away from earth, keeping these places cooler. But this situation can’t keep going indefinitely because physics dictates that cooler locations will warm up more and when they do, the clouds will dwindle and more heating will occur, Dessler said.

Previous studies were based on the cooler spots staying that way, but Dessler and colleagues say that’s not likely.

Outside experts said the work is based on compelling reasoning, but want more research to show that it’s true. Breakthrough Institute climate scientist Zeke Hausfather said the new work fits better with climate models than observational data.

Just because the world is bound to get more warming than international goals, that doesn’t mean all is lost in the fight against global warming, said Dessler, who cautioned against what he called “climate doomers.”

If the world gets to net zero carbon emissions soon, 2 degrees of global warming could be delayed enough so that it won’t happen for centuries, giving society time to adapt or even come up with technological fixes, he said.

“If we don’t, we’re going to blow through (climate goals) in a few decades,” Dessler said. “It’s really the rate of warming that makes climate change so terrible. If we got a few degrees over 100,000 years, that would not be that big a deal. We can deal with that. But a few degrees over 100 years is really bad.”

Could we ever pull enough carbon out of the atmosphere to stop climate change?

By Donavyn Coffey a day ago

Planting trees helps, but what are other ways?

Planting 1 trillion trees is one way to store unwanted carbon.Planting 1 trillion trees is one way to store unwanted carbon.(Image: © Shutterstock)

Nature has equipped Earth with several giant “sponges,” or carbon sinks, that can help humans battle climate change. These natural sponges, as well as human-made ones, can sop up carbon, effectively removing it from the atmosphere. 

But what does this sci-fi-like act really entail? And how much will it actually take — and cost — to make a difference and slow climate change

Sabine Fuss has been looking for these answers for the last two years. An economist in Berlin, Fuss leads a research group at the Mercator Research Institute on Global Commons and Climate Change and was part of the original Intergovernmental Panel on Climate Change (IPCC) — established by the United Nations to assess the science, risks and impacts of global warming. After the panel’s 2018 report and the new Paris Agreement goal to keep global warming to 2.7 degrees Fahrenheit (1.5 degrees Celsius) or less, Fuss was tasked with finding out which carbon removal strategies were most promising and feasible. 

Related: What is a carbon sink?Click here for more videos…CLOSE 0% PLAY SOUND

Afforestation and reforestation — planting or replanting of forests, respectively — are well known natural carbon sinks. Vast numbers of trees can sequester the greenhouse gas carbon dioxide (CO2) from the atmosphere for photosynthesis, a chemical reaction that uses the sun’s energy to turn carbon dioxide and water into sugar and oxygen. According to a 2019 study in the journal Science, planting 1 trillion trees could store about 225 billion tons (205 billion metric tons) of carbon, or about two-thirds of the carbon released by humans into the atmosphere since the Industrial Revolution began. 

Agriculture land management is another natural carbon removal approach that’s relatively low risk and already being tested out, according to Jane Zelikova, terrestrial ecologist and chief scientist at Carbon180, a nonprofit that advocates for carbon removal strategies in the U.S. Practices such as rotational grazing, reduced tilling and crop rotation increase carbon intake by photosynthesis, and that carbon is eventually stored in root tissues that decompose in the soil. The National Academy of Sciences found that carbon storage in soil was enough to offset as much as 10% of U.S. annual net emissions — or about 632 million tons (574 million metric tons) of CO2 — at a low cost. 

But nature-based carbon removal, like planting and replanting forests, can conflict with other policy goals, like food production, Fuss said. Scaled up, these strategies require a lot of land, oftentimes land that’s already in use. 

This is why more tech-based approaches to carbon removal are crucial, they say. With direct air capture and carbon storage, for instance, a chemical process takes carbon dioxide out of the air and binds it to filters. When the filter is heated, the CO2 can be captured and then injected underground. There are currently 15 direct air capture plants worldwide, according to the International Energy Agency. There’s also bioenergy with carbon capture. With this method, plants and trees are grown, creating a carbon sink, and then the organic material is burned to produce heat or fuel known as bioenergy. During combustion, the carbon emissions are captured and stored underground. Another carbon capture trick involves mineralization; in this process, rocks get ground up to increase the surfaces available to chemically react with, and crystallize, CO2. Afterward, the mineralized CO2 is stored underground. 

However, none of these technologies have been implemented on a large scale. They’re extremely expensive, with estimates as high as $400 per ton of CO2 removed, and each still requires a lot of research and support before being deployed. But the U.S. is a good example of how a mix of carbon removal solutions could work together, Zelikova said: Land management could be used in the agricultural Midwest; basalt rocks in the Pacific Northwest are great for mineralization; and the oil fields in the Southwest are already primed with the right technology and skilled workers for underground carbon storage, she said. 

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Ultimately, every country will have to put together its own unique portfolio of CO2 removal strategies because no single intervention will be successful on its own. “If we scaled up any of them exclusively, it would be a disaster,” Fuss said. “It would use a lot of land or be prohibitively expensive.” Her research has shown that afforestation and reforestation will be most productive in tropical regions, whereas solar radiation differences in the more northern latitudes with more albedo (reflection of light back into space) mean those countries will likely have better luck investing in the more technological interventions, such as carbon capture and biomass extraction.

The need to deploy these solutions is imminent. The global carbon budget, the amount of CO2 humans can emit before the global temperature rises 2.7 F (1.5 C) above preindustrial levels, is about 300 gigatons of CO2, Fuss said. RELATED MYSTERIES

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“In recent years, we’ve emitted 40 gigatons,” she said. Put another way, only a few years are left in that budget. A recent study in the journal Scientific Reports suggests that waiting even a few years from now may be too late if we are to meet the goal set in the Paris Agreement. Based on their climate model, the authors predict that even if we stop emitting greenhouse gases entirely, “global temperatures will be 3 C [5.4 F] warmer and sea levels 3 meters [10 feet] higher by 2500 than they were in 1850.” To reverse climate change’s effects, 33 gigatons of existing greenhouse gases must be removed this year and every year moving forward, the researchers said.  

The reality, however, is these approaches are not ready and there’s not a consensus on how to pay for them. There is a consensus among scientists on the next step: We need to stop further emissions immediately. But, “since emissions are embedded in our daily lives and infrastructure,” Fuss said, “[carbon] removal comes more to the forefront.”

Originally published on Live Science.

Carbon Capture Is Not a Climate Savior

December 24, 2020

The promise of negative emissions is baked into most “net zero” pledges. But putting that into practice is easier said than done.

Algae at the wastewater biofuel system at the San Francisco Public Utilities Commission's Southeast Water Pollution Control Plant (shown here in 2012) capture carbon dioxide and produce biofuel.SARAH RICE/GETTY IMAGESAlgae at the wastewater biofuel system at the San Francisco Public Utilities Commission’s Southeast Water Pollution Control Plant (shown here in 2012) capture carbon dioxide and produce biofuel.

In December, the Vatican became one of the latest entities to unveil a plan to reach net-zero emissions by 2050, joining far less pious actors like BP, Shell, and President-elect Joe Biden. Net-zero plans have become all the rage as public concern about the climate crisis has grown. But approving coverage of these wide-ranging announcements rarely question what the “net” of net-zero actually means. 

Meeting climate targets means releasing fewer fumes into the sky, for starters. And those plans include that. But they also include something else. The way they get to “zero” isn’t by cutting all greenhouse gas emissions by mid-century but by sucking carbon dioxide out of the atmosphere afterward through a suite of methods known collectively as “negative emissions.” And there’s a problem with that: Existing “carbon capture” technologies and techniques can today capture only 0.1 percent of global emissions. Banking on them to pick up the slack amounts to a big gamble. It’s not clear these techniques are scalable or that the countries and companies behind net-zero pledges have thought through what trying to scale them would mean.

Talking up carbon capture is good for fossil fuel companies—it makes the next few decades look profitable for them. Companies from ExxonMobil to Shell to Occidental Petroleum have all boasted about investments in carbon capture while continuing to double down on their core business model of finding and digging up as much oil and gas as possible. Whether they’re making meaningful investments in carbon capture is a different matter entirely. Exxon recently nixed its $1 billion investment to store carbon under a gas operation it owns in Wyoming. It moved ahead with a $9 billion expansion of its crude oil drilling operations off the coast of Guyana. All the while, Exxon, like its competitors, continues to advertise its token investments in carbon capture as proof that they’ve enlisted in good faith in the climate fight, despite all evidence to the contrary.Special OfferPostelection updates:
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The approach is eerily reminiscent of the climate denial playbook. When companies like Exxon and General Motors funded climate denial, the effect wasn’t to convince the world that more carbon dioxide is a good thing or that the earth just naturally gets really hot sometimes, but it was to muddy the waters, casting enough doubt on the scientific consensus to stymie policymaking that might threaten their profits. Now, such companies’ lavish advertising budgets are being used to spread a new kind of doubt in the face of a new consensus about how to deal with that problem: Phase out fossil fuel use as quickly as possible while phasing in renewables. Negative emissions are one among several vague talking points being thrown out by polluters to suggest that isn’t necessary. What if we could suck up a whole lot of carbon dioxide at some point? What if the timeline for decarbonization could be pushed back as a result? The jury’s still out on how much carbon dioxide we can take out of the atmosphere after 2050, they argue. And renewables can’t yet meet the world’s energy needs. So it’s probably safest to let us keep making the earth hotter while our best researchers work to find a technological fix to this problem that’s just around the corner. 

Here’s the sticky bit: Negative emissions are needed if the world’s governments are indeed serious about keeping warming to “well below” 2 degrees Celsius, per the text of the Paris Agreement. Anything higher than 1.5 degrees may well amount to a death sentence for potentially millions across the global south, and the lack of zero-carbon alternatives on offer in big sectors of the economy mean it’d be all too possible to sail past that threshold in the decades to come. Carbon capture is necessary. But fossil fuel executives are the last people who should get to define how much of it’s needed, what it should look like, and who benefits.

“It’s important to know how many gigatons we can take out of the air and the economic efficiency,” Georgetown University’s Olúfẹ́mi Táíwò, whose research explores the intersections of climate justice and colonialism, told me. In a forthcoming primer on carbon dioxide removal, or CDR, Harvard University researchers Andrew Bergman and Toly Rinberg suggest that around 1 metric gigaton of removal per year, worldwide,is consistent with a pathway toward capping warming at 1.5 degrees Celsius—far less than the 5 to 15 metric gigatons suggested by the models used by the Intergovernmental Panel on Climate Change, or IPCC. 

Even more modest targets will require technology that is currently quite expensive, probably in addition to large quantities of land for carbon sinks. The Integrated Assessment Models, or IAMs, used by the IPCC to design net-zero pledges pose deceptively simple answers to this challenge. In assuming a continued annual GDP growth of around 2 percent, year on year, carbon capture technologies that are expensive to deploy now will get cheaper in the future. So long as our future selves and countries are richer, it’ll be cheaper and easier to suck up carbon at evermore impressive scales down the line—more so, say, than phasing out fossil fuels and deploying lots of renewables in the next 20 years. We don’t actually know, though, if societies getting richer means they’ll be able to capture more carbon—particularly given the stubborn fact that GDP and emissions tend to rise together.

Carbon capture, or negative emissions, can mean many different things. So-called “natural climate solutions” involve things like tree planting, grassland and wetland restoration, or (controversially) agriculture-based soil sequestration. The Green New Deal resolution introduced to Congress last year backed this approach, citing the need for “removing greenhouse gases from the atmosphere and reducing pollution by restoring natural ecosystems through proven low-tech solutions that increase soil carbon storage, such as land preservation and afforestation.” But there are other approaches, too. Among the most frequently invoked in climate modeling is Bioenergy with Carbon Capture and Storage, or BECCS. This relies on harvesting new carbon-sucking crops like switchgrass for fuel, then capturing the resulting emissions through machines that filter out emissions from where the power is generated. And in direct air capture, machines that look like air conditioners suck carbon down from the sky and inject it into rock formations or soft drinks, among other uses. Special OfferPostelection updates:
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In some industries, carbon capture makes intuitive sense—for example, in aviation, where sustainable fuel solutions are going to take a while to develop. In others, carbon capture can serve to reduce emissions from activities that should be eliminated outright. A good example of this are so-called “scrubbers” on gas and coal-fired power plants. These lessen the amount of carbon they’re spewing into the atmosphere with the help of a recently bolstered federal tax credit known as 45Q. This isn’t a negative emissions technology, since pollution is still happening. Such poorly targeted subsidies for carbon capture and storage, or CCS, could even extend the life of already uneconomical power stations that should be among the first things phased out as part of any earnest decarbonization agenda.

“If you’re doing aggressive mitigation, the coal for CCS option essentially falls off the table,” Glen Peters, research director at the Center for International Climate Research, says. “You need both to happen: aggressive mitigation, while starting to figure out the technologies you’ll need for the last 20 to 30 percent.” Despite platitudes from Republicans, former energy secretaries, and even some parts of organized labor about the supposed promise of “clean coal,” no amount of tax credits will change the fact that coal remains a bad investment in just about every sense. 

Innovation is a seductive concept. Given that Republicans are particularly keen on it, investing in negative emissions technologymight seem like low-hanging fruit for climate policy in a divided government; just this week, $35 billion in research funding—including roughly $6 billion for carbon capture—made it into the broad spending bill now sitting on Trump’s desk. 

Much of the policy support for negative emissions on offer now, though—and that can garner bipartisan support—tends to take the form of sloppily designed corporate subsidies for polluters like 45Q. The vast majority of the carbon captured on earth today is poured back into extraction. Enhanced Oil Recovery, or EOR, utilizes carbon by injecting it underground to help unearth more fossil fuels from wells. 45Q—created to spur on a domestic carbon capture and storage industry—furnishes generous subsidies on “clean coal” and EOR alike. Unsurprisingly, fossil fuel interests have consistently sought to degrade the reporting requirements for such credits. A 2018 study by Clean Water Action found that just three of the 60 million metric tons worth of 45Q tax credits claimed as of that spring had been reported to the EPA’s verification process.  

“Moving forward, we have to completely change how we’re tackling this type of technology,” Shuchi Talati, a senior policy adviser at Carbon 180, told me. “We really need to have more broad participatory conversations on what infrastructure means for these kinds of projects. Things like carbon dioxide pipelines will be needed at scale. I think having conversations that include labor, environmental justice, and community groups and local governments need to be had at the beginning,” she added, noting the need in particular for international governance.

“Land use, respecting the rights of indigenous peoples and low-income communities, questions of community benefits agreements, who’s going to get the jobs these projects create … These are all things we should know. I just don’t think ExxonMobil is going to ask those questions, much less answer them in any kind of serious way,” said Táíwò.

Carbon dioxide removal projects, wrote Táíwò, Talati, and several other researchers across disciplines in a recent paper in One Earth, need to be evaluated “on a case-specific basis rather than just as abstract technologies.” In a country where rural, mostly white landowners can still stymie vital wind farm and transmission line projects, comparatively little attention is paid to potential resistance to negative emissions. Removing just a single metric gigaton of carbon per yearwould require a land area bigger than Texas. Stabilizing temperatures at the same level through BECCS alone, per many IAMs, is estimated to require a landmass five times the size of India. And a recent Nature Climate Change study finds that relying primarily on more “natural” negative emissions to stabilize warming at 1.5 degrees could trigger a five-fold increase in staple food crop price. 

Already, troubling patterns have emerged. As Táíwò has pointed out, Africa—where land ownership is increasingly concentrated—now accounts for 75 percent of the land pledged under the “Bonn Challenge” to restore 350 million hectares of forest. Having the “net” of “net-zero” pledges happen out of sight and out of mind for global north countries could see the dynamics of capturing carbon look a lot like those that were erected to dig it out of the ground. Making matters worse is the fact that decades of multilateral programs, from REDD+ to the Bonn Challenge, have treated large swathes of the global south as an inexhaustible carbon sink. Having contributed just 3 percent of global emissions since 1751, Táíwò says, it’s “absurd that the African continent should have to deal with the land use costs of carbon removal.” 

“Carbon removal in particular is one of the most direct forms of climate reparations,” he added. “Global north countries taking on carbon removal is obviously not exhaustive of their responsibilities from a justice perspective, but in a lot of ways is the most direct thing they can do conceptually speaking.” A more just approach would be for global north countries to fund carbon removal and site much of it in their own backyards.

But while less land-use intensive, direct-air capture technologies have their own feasibility and affordability issues. For one, they depend on an enormous amount of electricity; if the grid powering DAC is still carbon-intensive, its carbon savings look a lot more ambiguous. Andif such technologies are patented by private companies, onerous intellectual property statutes could make it virtually impossible for them to proliferate widely, particularly to low- and middle-income countries that lack the capacity to pay the rents that might be demanded by patent holders. Wealthy countries’ recent refusals to waive intellectual property rights for publicly funded Covid-19 vaccines, Táíwò notes, could offer a preview for how IP rules may stymie a new generation of life-saving technologies. 

True negative emissions—mostly, capturing carbon and keeping it buried—aren’t neatly compatible with the profit motive. Even if captured carbon is used to make building materials, acknowledging that negative emissions are critical to ward off climate catastrophe means making sure that installing them quickly doesn’t depend on their ability to turn a profit. Lavishing private companies with subsidies and tax incentives, that is, will only go so far. Instead, we might need to treat carbon like sewage, as science fiction writer Kim Stanley Robinson recently proposed: an essential but basically boring public service that nobody expects to get rich off of unless there’s something illicit happening. 

As fossil fuel companies look to capture the field of captured carbon with schemes for EOR and pernicious academic funding, there’s a dire need for democratic governance models for carbon dioxide removal that prioritize equity and emissions reductions over shareholders. Environmental sociologist Holly Jean Buck argues that carbon capture could fall under the mandate of nationalized fossil fuel companies, which could keep union workers on the payroll as they build out the vast amount of infrastructure needed to store carbon. As the One Earth paper coauthored by Buck also notes, “We might need to stretch our imaginations to envision economic and political futures in which CDR fits into the world we want rather than delaying or undermining it.”

The proliferation of net-zero plans in 2020 is clearly good news insofar as it indicates that governments are now taking the climate crisis more seriously. But they also belie the need for concrete plans to reduce emissions much sooner. “The scenarios are performative in a sense that they show us one way but not all the ways to 1.5 or 2 degrees,” Glen Peters explained. Earlier climate models, he said, were designed around stabilizing atmospheric concentrations of carbon dioxide, say around 450 or 550 parts per million. “But many models couldn’t get to this,” he said. “So what they did is change that target to only apply in 2100, so you could go over and come back down. All the models could do this if they used BECCS.” Such models can be useful reference points but don’t need to dictate what’s possible. 

What caused the ice ages? Tiny ocean fossils offer key evidence

DECEMBER 10, 2020

by Liz Fuller-Wright, Princeton University

What caused the ice ages? Tiny ocean fossils offer key evidence
This diatom species, Fragilariopsis kerguelensis, is a floating algae that is abundant in the Antarctic Ocean and was the major species in the samples collected for the study by Princeton University and the Max Planck Institute for Chemistry. These microscopic organisms live near the sea surface, then die and sink to the sea floor. The nitrogen isotopes in their shells vary with the amount of unused nitrogen in the surface water. The researchers used that to trace nitrogen concentrations in Antarctic surface waters over the past 150,000 years, covering two ice ages and two warm interglacial periods. Credit: Philipp Assmy (Norwegian Polar Institute) and Marina Montresor (Stazione Zoologica Anton Dohrn)

The last million years of Earth history have been characterized by frequent “glacial-interglacial cycles,” large swings in climate that are linked to the growing and shrinking of massive, continent-spanning ice sheets. These cycles are triggered by subtle oscillations in Earth’s orbit and rotation, but the orbital oscillations are too subtle to explain the large changes in climate.

“The cause of the ice ages is one of the great unsolved problems in the geosciences,” said Daniel Sigman, the Dusenbury Professor of Geological and Geophysical Sciences. “Explaining this dominant climate phenomenon will improve our ability to predict future climate change.”

In the 1970s, scientists discovered that the concentration of the atmospheric greenhouse gas carbon dioxide (CO2) was about 30% lower during the ice ages. That prompted theories that the decrease in atmospheric CO2 levels is a key ingredient in the glacial cycles, but the causes of the CO2 change remained unknown. Some data suggested that, during ice ages, CO2 was trapped in the deep ocean, but the reason for this was debated.

Now, an international collaboration led by scientists from Princeton University and the Max Planck Institute for Chemistry (MPIC) have found evidence indicating that during ice ages, changes in the surface waters of the Antarctic Ocean worked to store more CO2 in the deep ocean. Using sediment cores from the Antarctic Ocean, the researchers generated detailed records of the chemical composition of organic matter trapped in the fossils of diatoms—floating algae that grew in the surface waters, then died and sank to the sea floor. Their measurements provide evidence for systematic reductions in wind-driven upwelling in the Antarctic Ocean during the ice ages. The research appears in the current issue of the journal Science.

For decades, researchers have known that the growth and sinking of marine algae pumps CO2 deep into the ocean, a process often referred to as the “biological pump.” The biological pump is driven mostly by the tropical, subtropical and temperate oceans and is inefficient closer to the poles, where CO2 is vented back to the atmosphere by the rapid exposure of deep waters to the surface. The worst offender is the Antarctic Ocean: the strong eastward winds encircling the Antarctic continent pull CO2-rich deep water up to the surface, “leaking” CO2 to the atmosphere.×280&!1&btvi=1&fsb=1&xpc=O8lYBHvjyS&p=https%3A//

The potential for a reduction in wind-driven upwelling to keep more CO2 in the ocean, and thus to explain the ice age atmospheric CO2 drawdown, has also been recognized for decades. Until now, however, scientists have lacked a way to unambiguously test for such a change.

The Princeton-MPIC collaboration has developed such an approach, using tiny diatoms. Diatoms are floating algae that grow abundantly in Antarctic surface waters, and their silica shells accumulate in deep sea sediment. The nitrogen isotopes in diatoms’ shells vary with the amount of unused nitrogen in the surface water. The Princeton-MPIC team measured the nitrogen isotope ratios of the trace organic matter trapped in the mineral walls of these fossils, which revealed the evolution of nitrogen concentrations in Antarctic surface waters over the past 150,000 years, covering two ice ages and two warm interglacial periods.

“Analysis of the nitrogen isotopes trapped in fossils like diatoms reveals the surface nitrogen concentration in the past,” said Ellen Ai, first author of the study and a Princeton graduate student working with Sigman and with the groups of Alfredo Martínez-García and Gerald Haug at MPIC. “Deep water has high concentrations of the nitrogen that algae rely on. The more upwelling that occurs in the Antarctic, the higher the nitrogen concentration in the surface water. So our results also allowed us to reconstruct Antarctic upwelling changes.”

What caused the ice ages? Tiny ocean fossils offer key evidence
This diatom species, Fragilariopsis kerguelensis, is a floating algae that is abundant in the Antarctic Ocean and was the major species in the samples collected for the study by Princeton University and the Max Planck Institute for Chemistry. These microscopic organisms live near the sea surface, then die and sink to the sea floor. The nitrogen isotopes in their shells vary with the amount of unused nitrogen in the surface water. The researchers used that to trace nitrogen concentrations in Antarctic surface waters over the past 150,000 years, covering two ice ages and two warm interglacial periods. Credit: (c) Michael Kloster, Alfred-Wegener-Institute

The data were made more powerful by a new approach for dating the Antarctic sediments. Surface water temperature change was reconstructed in the sediment cores and compared with Antarctic ice core records of air temperature.

“This allowed us to connect many features in the diatom nitrogen record to coincident climate and ocean changes from across the globe,” said Martínez-García. “In particular, we are now able to pin down the timing of upwelling decline, when climate starts to cool, as well as to connect upwelling changes in the Antarctic with the fast climate oscillations during ice ages.”

This more precise timing allowed the researchers to home in on the winds as the key driver of the upwelling changes.

The new findings also allowed the researchers to disentangle how the changes in Antarctic upwelling and atmospheric CO2 are linked to the orbital triggers of the glacial cycles, bringing scientists a step closer to a complete theory for the origin of the ice ages.

“Our findings show that upwelling-driven atmospheric CO2 change was central to the cycles, but not always in the way that many of us had assumed,” said Sigman. “For example, rather than accelerating the descent into the ice ages, Antarctic upwelling caused CO2 changes that prolonged the warmest climates.”

Their findings also have implications for predicting how the ocean will respond to global warming. Computer models have yielded ambiguous results on the sensitivity of polar winds to climate change. The researchers’ observation of a major intensification in wind-driven upwelling in the Antarctic Ocean during warm periods of the past suggests that upwelling will also strengthen under global warming. Stronger Antarctic upwelling is likely to accelerate the ocean’s absorption of heat from ongoing global warming, while also impacting the biological conditions of the Antarctic Ocean and the ice on Antarctica.

“The new findings suggest that the atmosphere and ocean around Antarctica will change greatly in the coming century,” said Ai. “However, because the CO2 from fossil fuel burning is unique to the current times, more work is needed to understand how Antarctic Ocean changes will affect the rate at which the ocean absorbs this CO2.”

“Southern Ocean upwelling, Earth’s obliquity, and glacial-interglacial atmospheric CO2 change” by Xuyuan Ellen Ai, Anja S. Studer, Daniel M. Sigman, Alfredo Martínez-García, François Fripiat, Lena M. Thöle, Elisabeth Michel, Julia Gottschalk, Laura Arnold, Simone Moretti, Mareike Schmitt, Sergey Oleynik, Samuel L. Jaccard and Gerald H. Haug appears in the Dec. 11 issue of Science.

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