carbon sequestration – Artifex.News https://artifexnews.net Stay Connected. Stay Informed. Mon, 12 Aug 2024 00:00:00 +0000 en-US hourly 1 https://wordpress.org/?v=6.6.2 https://artifexnews.net/wp-content/uploads/2023/08/cropped-Artifex-Round-32x32.png carbon sequestration – Artifex.News https://artifexnews.net 32 32 Cold War nuke tests light up problem with present-day climate models https://artifexnews.net/article68512069-ece/ Mon, 12 Aug 2024 00:00:00 +0000 https://artifexnews.net/article68512069-ece/ Read More “Cold War nuke tests light up problem with present-day climate models” »

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For billions of years, the carbon cycle has been nature’s solution to removing excess carbon from the atmosphere.

In nature, volcanic eruptions and life forms vent carbon dioxide (CO2) into the atmosphere. Plants and trees then draw in and store this CO2 during photosynthesis.

Of late, the carbon cycle has been a focus area in climate mitigation. Plants’ ability to lock away carbon produced by burning fossil fuels can offer respite. Both fossil-fuel corporations and governments have subscribed to this idea as they look for ways to offset their still-rising carbon footprints.

But a study recently published in the journal Science by an international team of researchers suggests plants absorb more CO2 from the atmosphere than expected and also store it for a shorter duration than expected, before releasing it into their surroundings.

To establish their findings, the researchers investigated the remains of nuclear bomb tests the U.S. and the Soviet Union conducted in the 1960s using climate models.

Relics of the Cold War

The dozens of nuclear bomb tests during the Cold War in the second half of the 20th century maintained an atmosphere of trepidation worldwide and, scientists later found, an opportunity for climate research.

“As terrible as they were, they’ve been quite useful to scientists,” Heather Graven, a climate physicist at Imperial College London and the study’s lead author, said.

The explosions sprayed radioactive material around the planet, including a lot of it in the atmosphere. One of them was carbon-14, an isotope also called radiocarbon. Its atom’s nucleus has two neutrons more than in the nucleus of the more common carbon-12. Radiocarbon is naturally found in minute quantities but the nuclear bomb tests steadily deposited more and more of it in the atmosphere.

In 1963, Cold War powers signed the Limited Test Ban Treaty (LTBT) that prohibited nuclear testing over land, air, and under water. The atmospheric radiocarbon concentration stopped increasing beyond this year. Dr. Graven and her team used models to track the change in this level between 1963 and 1967 and found that it dropped steadily.

Often, radiocarbon bonds with oxygen to form CO2. Plants, trees, and other vegetation absorb this CO2 during photosynthesis to produce food and ultimately energy. The researchers found that the models suggested the radiocarbon was moving into vegetation from the atmosphere.

‘The whole system is cycling faster’

Plants need food to survive and they make it themselves. They absorb CO2 from the atmosphere during photosynthesis and use it to make glucose. A plant consumes some of the glucose and some it stores as starch in its leaves. In this process, some carbon is also lost when the plant exhales CO2 as it respirates.

Scientists don’t have a direct way to measure the rates at which vegetation loses and gains carbon. But they have been able to use satellite data to estimate how much carbon vegetation around the world hosts.

The researchers behind the new study used climate models to estimate the amount of carbon stored in vegetation around the planet in a year. Previous studies had shown this value to be at least 43-76 billion tonnes of carbon per year worldwide. But the study team said it could be around 80 billion tonnes per year, with most of the carbon being stored in leaves and finer roots, i.e. the non-woody parts of the plant.

If the higher value is accurate, plants must also be shedding their carbon sooner than thought. Otherwise, the researchers figured, they would have more carbon than estimated based on satellite data.

The findings also shed light on how quickly carbon is exchanged between vegetation and the atmosphere. “The whole system is kind of cycling faster than what we thought before,” Dr. Graven said.

But Raghu Murtugudde, a climate scientist at IIT Bombay who wasn’t involved in the study, advised caution. “To say what the actual impact on the carbon cycle is would be a challenge,” he told The Hindu. “Theoretically you want to include all the details [in the models] but there are missing understandings and lack of data and irreducible uncertainties.”

He said the models simulating carbon stored in vegetation in the study make assumptions that, if tweaked, could change the results significantly.

The study’s co-author Will Wieder, a climate scientist with the U.S. National Center for Atmospheric Research, said Dr. Murtugudde’s statement was “accurate” but also “short-sighted”.

Radioactive representation

In 1995, the World Climate Research Program set up the Coupled Model Intercomparison Project (CMIP), which prepares climate projections that inform the U.N.’s climate reports.

For the CMIP, scientific institutions in several countries pool their individual climate models together to produce better projections. But most of these models haven’t been tested with radiocarbon data.

It’s not difficult to input this data, according to Dr. Graven. “Some of them haven’t really bothered to do so.”

In fact, only one model, the ‘Community Earth System Model 2’ developed by the U.S. University Corporation for Atmospheric Research, accounted for radiocarbon in its simulations — but it also predicted plants had absorbed much less radiocarbon than Dr Graven & co. found they should. 

Climate models have always had uncertainties.

“They are not wrong. They are imperfect,” Dr. Murtugudde said. “It’s like a car that pulls to one side but it can be driven. So it needs to be looked at by a mechanic to make sure it eventually drives straight.”

The CMIP models used in the study included some of the latest versions (5 and 6). The short-falls highlighted in the study are more of a stepping stone for future research into climate modelling, according to Dr. Wieder. “This kind of information is critical as we work to improve the models for CMIP 7 and beyond.”

This said, all these climate scientists agreed radiocarbon needs to be represented better in climate predictions. So far, radiocarbon inclusion has been plagued by “limited resources, both funding and effort, available for model development and observational research,” Govindasamy Bala, a climate physicist at the Indian Institute of Science, Bengaluru not involved in the study, told The Hindu.

“Representation of isotopes, ice sheet dynamics, permafrost, etc. in models is likely to gain momentum in the future,” he added.

Karthik Vinod is a freelance science journalist and co-founder of Ed Publica. He has masters’ degrees in astrophysics and science, technology and society.



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European carbon removal specialists to support new projects in India https://artifexnews.net/article68384616-ece/ Tue, 09 Jul 2024 11:09:29 +0000 https://artifexnews.net/article68384616-ece/ Read More “European carbon removal specialists to support new projects in India” »

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Steam emits from a crude oil refinery in Kochi, Kerala state, India, on Aug. 26, 2022.
| Photo Credit: Ap

A team of European carbon removal specialists launched an initiative on Tuesday to help Indian businesses develop projects that suck carbon dioxide out the atmosphere and mitigate global warming.

The Amsterdam-based group, called remove, has raised more than 220 million euros ($238 million) to support carbon dioxide removal (CDR) projects throughout Europe, and will now accept applications from Indian start-ups.

Successful applicants will gain access to remove’s network of experts and international buyers, and could be eligible for additional funding.

“We have now found the model that works,” said Marian Krueger, remove’s co-founder. “We believe this is a global problem and there is tremendous potential in other geographies beyond Europe.”

CDR refers to a wide range of interventions that sequester CO2 that has already been emitted. It includes reforestation and filters that extract carbon directly from the air.

Indian projects are expected to focus on biochar – charcoal produced from burning organic matter – as well as “enhanced weathering”, where materials like basalt are spread across land to absorb CO2.

Around 7-9 billion metric tons of CO2 need to be removed annually to keep temperature rises below the key 1.5 degree Celsius threshold, up from 2 billion tons currently, researchers have said.

The value of the CDR market could rise from $2.27 billion in 2023 to around $100 billion by 2030 if barriers to growth are addressed, a consultancy also said last month.

CDR projects are more expensive than conventional CO2 reduction, and their viability will depend on carbon markets. Demand for CDR credits is currently limited to a few dozen mainly philanthropic buyers on the voluntary market, including the U.S. federal government, Microsoft and Google.

“We all know we will need carbon removal down the line – the pot of gold at the end is very big, but right now … it really is a matter of survival until we finally hit the point where the market finally materialises,” said Krueger.

The European Union is currently exploring options to include CDR credits in its emissions trading system.

“We are going to need this to become far more mainstream than it currently is,” said Steve Smith, a CDR expert at Oxford University.

“I think that is going to have to involve governments stepping in to create the conditions for it to become mainstream.”



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World’s oldest termite mounds found in South Africa, storing carbon for millennia https://artifexnews.net/article68316171-ece/ Fri, 21 Jun 2024 11:58:14 +0000 https://artifexnews.net/article68316171-ece/ Read More “World’s oldest termite mounds found in South Africa, storing carbon for millennia” »

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Image for Representation.
| Photo Credit: The Hindu

The landscape along the Buffels River in South Africa’s Namaqualand region is dotted with thousands of sandy mounds that occupy about 20% of the surface area. These heuweltjies, as the locals call them (the word means “little hills” in Afrikaans), are termite mounds, inhabited by an underground network of tunnels and nests of the southern harvester termite, Microhodotermes viator.

I’m part of a group of earth scientists who, in 2021, set out to study why the groundwater in the area, around 530km from Cape Town, is saline. The groundwater salinity seemed to be specifically related to the location of these heuweltjies. We used radiocarbon dating; dating the mounds, we reasoned, would allow us to see when minerals that were stored in the mounds were flushed to the groundwater.

The tests revealed far more than we expected: Namaqualand’s heuweltjies, it turns out, are the world’s oldest inhabited termite mounds. Some date as far back as between 34,000 and 13,000 years. The oldest previously known inhabited mounds were 4,000 years old (from a different termite species from Brazil) and 2,300 years old (from central Congo).

This is more than just an interesting scientific find or historical curiosity. It offers a window into what our planet looked like tens of thousands of years ago, providing a living archive of environmental conditions that shaped our world.

It is also hugely important today: there is growing evidence that termites have a substantial, but still poorly understood, role in the carbon cycle. By studying these and other termite mounds, scientists can gain a better understanding of how to sequester (store) carbon. This process removes CO₂ from the atmosphere and is vital for mitigating climate change.

Carbon storage

Namaqualand is a global biodiversity hotspot renowned for its spring flowers, but it is a dry area. Surface water is in short supply and the groundwater is saline.

Although most of Namaqualand receives very little rainfall, there are rare, high intensity rainfall events. When these do occur, the termite burrows on the mound surfaces serve as water flow paths that can harvest rain and channel water into the mound. This causes the salts that built up in the mounds over thousands of years to be flushed into the groundwater system via flow paths created by the tunnelling action of the termites, pushing the dissolved minerals ever deeper. This process also pushes down the carbon that slowly built up in the centre of the mounds when termites collected plant material and brought it into the mound over millennia.

The ability of these mounds to sequester carbon is linked to the termites’ unique behaviour. The insects transport organic material – such as small sticks about 2cm long and a few millimetres wide from small woody plants – deep into the soil. This way, fresh stores of carbon are continuously added at depths greater than one metre. Deep storage reduces the likelihood of organic carbon being released back into the atmosphere. So the mound acts as a long-term carbon sink.

Not only do the termites take the organic carbon material deep underground into their nests, but their tunnels also allow dissolved inorganic carbon (known as soil calcite or calcium carbonate) in the mound soil to move into the groundwater along with other soluble minerals. So the termite mounds also offer a mechanism to sequester carbon dioxide through dissolution and leaching of soil carbonate-bicarbonate to groundwater. This is a long term carbon storage method that carbon storage companies are trying to replicate to reduce atmospheric carbon.

The results of our radiocarbon dating of both the organic and inorganic carbon in this soil show that the mounds have been accumulating organic matter and nutrients, including carbon, for tens of thousands of years. This enrichment is one of the reasons that Namaqualand’s famous wildflowers are so prominent on the mounds in spring.

During the mounds’ formation, the region experienced more rainfall than it does today. Studying the layers of the mounds and looking at the carbon, sulphur, and oxygen isotopes preserved in the mounds and in the groundwater showed that periods of higher rainfall in the region were associated with global climate cooling. These cooler and wetter periods were associated with the leaching of accumulated carbon and other minerals to the groundwater.

Tiny engineers

These findings are further evidence that termites fully deserve their reputation as ecosystem engineers. They modify their soil surroundings to maintain ideal humidity and temperature conditions, and their foraging paths extend many tens of metres.

We argue that, given what we’ve uncovered in Namaqualand, termite activity should be incorporated into carbon models. These primarily focus on forests and oceans; including termite mounds can help provide a more comprehensive understanding of global carbon dynamics. In Namaqualand, mounds occupy 27% of the total area but contribute 44 % of the total soil organic carbon stock. This highlights the disproportionate contribution termite mounds make to carbon stocks in these semi-arid environments.

Public awareness and policy integration are key, too. Termite mounds are often cleared for agriculture or termites are considered pests. Raising awareness about the ecological importance of termite mounds and integrating these findings into environmental policies can help promote practices that support natural carbon sinks.

This research was conducted by a dedicated team from Stellenbosch University in South Africa (Department of Soil Science and Department of Earth Sciences), in collaboration with experts from the Institute for Nuclear Research in Hungary. C.E. Clarke, M.L. Francis , M. Hattingh, J.A. Miller, T. Nel, B. J Sakala, J. van Gend, N Vermonti, M. Vermooten (Kleyn), A. Watson (South Africa), L. Palcsu , A. Horvaěth M. Molnár T. Kertész (Hungary).

This article is republished from The Conversation under a Creative Commons license. Read the original article.



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Iceland’s ‘Mammoth’ raises potential for carbon capture https://artifexnews.net/article68160386-ece/ Fri, 10 May 2024 07:32:59 +0000 https://artifexnews.net/article68160386-ece/ Read More “Iceland’s ‘Mammoth’ raises potential for carbon capture” »

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A plaque for “Mammoth”, the new plant of Swiss start-up Climeworks is pictured in Hellisheidi, Iceland on May 8, 2024. A Swiss start-up unveiled on May 8, 2024 its second plant in Iceland sucking carbon dioxide from the air and stocking it underground, scaling up its capacity tenfold with the aim of eliminating millions of tonnes of CO2 by 2030.
| Photo Credit: AFP

With Mammoth’s 72 industrial fans, Swiss start-up Climeworks intends to suck 36,000 tonnes of CO2 from the air annually to bury underground, vying to prove the technology has a place in the fight against global warming.

Mammoth, the largest carbon dioxide capture and storage facility of its kind, launched operations this week situated on a dormant volcano in Iceland.

It adds significant capacity to the Climework’s first project Orca, which also sucks the primary greenhouse gas fuelling climate change from the atmosphere.

Just 50 kilometres (31 miles) from an active volcano, the seemingly risky site was chosen for its proximity to the Hellisheidi geothermal energy plant necessary to power the facility’s fans and heat chemical filters to extract CO2 with water vapour.

CO2 is then separated from the steam and compressed in a hangar where huge pipes crisscross.

Finally, the gas is dissolved in water and pumped underground with a “sort of giant SodaStream”, said Bergur Sigfusson, chief system development officer for Carbfix which developed the process.

A well, drilled under a futuristic-looking dome, injects the water 700 metres (2,300 feet) down into volcanic basalt that makes up 90 percent of Iceland’s subsoil where it reacts with the magnesium, calcium and iron in the rock to form crystals — solid reservoirs of CO2.

For the world to achieve “carbon neutrality” by 2050, “we should be removing something like six to 16 billion tonnes of CO2 per year from the air”, said Jan Wurzbacher, co-founder and co-chief of Climeworks at the inauguration of the first 12 container fans at Mammoth.

“I quite strongly believe that a large share of these… need to be covered by technical solutions,” he said.

From kilo to gigatonnes

“Not we alone, not as a single company. Others should do that as well,” he added, setting his start-up of 520 employees the goal of surpassing millions of tonnes by 2030 and approaching a billion by 2050.

Three years after opening Orca, Climeworks will increase capacity from 4,000 to 40,000 tonnes of CO2 captured once Mammoth is at full capacity — but that represents just seconds of the world’s actual emissions.

According to the IPCC, the UN’s climate expert body, carbon removal technologies will be necessary to meet the targets of the 2015 Paris Agreement — but major reductions of emissions is the priority.

The role of direct air capture with carbon storage (DACCS) remains minor in the various climate models due to its high price and its deployment at a large scale depends on the availability of renewable energy.

Climeworks is a pioneer with the two first plants in the world to have surpassed the pilot stage at a cost around $1,000 per tonne captured. Wurzbacher expects the cost to decline to just $300 in 2030.

More than 20 new infrastructure projects, developed by various players and combining direct capture and storage, should be operational worldwide by 2030 with a capacity around 10 million of tonnes.

“We need probably around $10 billion to proceed over the next decade to deploy our assets” in the Unites States, Canada, Norway, Oman and also Kenya, said Christoph Gebald, Climeworks co-founder and co-chief, 10 times what the company has already raised.

Carbon credits

“When I’m standing now at Orca I think: ‘Oh this looks like a little bit like Lego bricks’. It’s a tiny thing compared to Mammoth,” Wurzbacher said.

Lego bought carbon credits generated by Climeworks for every tonne of CO2 stored.

The credits are a way for making the solution known to the general public, Gebald said, who has not ruled out selling credits to “big polluters” as well.

Critics of the technology point to the risk of giving them “licence to pollute” or diverting billions of dollars that could be better invested in readily available technology like renewable energy or electric vehicles.

Climeworks claims to target “incompressible” emissions, after reduction.

The recipe is complex: optimise costs without competing with the growing need for renewable energy, more innovation, public and private funding, with storage infrastructure to follow.

“We are currently doing a pilot testing of using seawater for injection,” Sandra Osk Snaebjorndottir, chief scientist at Carbfix.

This procedure would allow the use of seawater for the mineralisation of CO2, near a port built by the Icelandic company to receive carbon dioxide from other countries.



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