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Sulphur Hexafluoride (SF6) Emissions drive rising greenhouse gas impacts in electrical switchgear, power grids, and renewables, with extreme global warming potential, long atmospheric lifetime, and leakage risks challenging climate targets and grid decarbonization.

Key Points

SF6 emissions are leaks from electrical switchgear and grids, a high-GWP gas with ~1,000-year lifetime.

✅ 23,500x CO2 global warming potential (GWP)

✅ Leaks from switchgear, breakers, gas-insulated substations

✅ Clean air and vacuum alternatives emerging for MV/HV

Sulphur hexafluoride, or SF6, is widely used in the electrical industry to prevent short circuits and accidents.

But leaks of the little-known gas in the UK and the rest of the EU in 2017 were the equivalent of putting an extra 1.3 million cars on the road.

Levels are rising as an unintended consequence of the green energy boom and the broader global energy transition worldwide.

Cheap and non-flammable, SF6 is a colourless, odourless, synthetic gas. It makes a hugely effective insulating material for medium and high-voltage electrical installations.

It is widely used across the industry, from large power stations to wind turbines to electrical sub-stations in towns and cities.

It prevents electrical accidents and fires.

However, the significant downside to using the gas is that it has the highest global warming potential of any known substance. It is 23,500 times more warming than carbon dioxide (CO2).

Just one kilogram of SF6 warms the Earth to the same extent as 24 people flying London to New York return.

It also persists in the atmosphere for a long time, warming the Earth for at least 1,000 years.

So why are we using more of this powerful warming gas?

The way we make electricity around the world is changing rapidly, with New Zealand's push to electrify in its energy system.

Where once large coal-fired power stations brought energy to millions, the drive to combat climate change and to move away from coal means they are now being replaced by mixed sources of power including wind, solar and gas.

This has resulted in many more connections to the electricity grid, and with EU electricity use could double by 2050, a rise in the number of electrical switches and circuit breakers that are needed to prevent serious accidents.

Collectively, these safety devices are called switchgear. The vast majority use SF6 gas to quench arcs and stop short circuits.

"As renewable projects are getting bigger and bigger, we have had to use it within wind turbines specifically," said Costa Pirgousis, an engineer with Scottish Power Renewables on its new East Anglia wind farm, which doesn't use SF6 in turbines.

"As we are putting in more and more turbines, we need more and more switchgear and, as a result, more SF6 is being introduced into big turbines off shore.

"It's been proven for years and we know how it works, and as a result it is very reliable and very low maintenance for us offshore."

How do we know that SF6 is increasing?

Across the entire UK network of power lines and substations, there are around one million kilograms of SF6 installed.

A study from the University of Cardiff found that across all transmission and distribution networks, the amount used was increasing by 30-40 tonnes per year.

This rise was also reflected across Europe with total emissions from the 28 member states in 2017 equivalent to 6.73 million tonnes of CO2. That's the same as the emissions from 1.3 million extra cars on the road for a year.

Researchers at the University of Bristol who monitor concentrations of warming gases in the atmosphere say they have seen significant rises in the last 20 years.

"We make measurements of SF6 in the background atmosphere," said Dr Matt Rigby, reader in atmospheric chemistry at Bristol.

"What we've seen is that the levels have increased substantially, and we've seen almost a doubling of the atmospheric concentration in the last two decades."

How does SF6 get into the atmosphere?

The most important means by which SF6 gets into the atmosphere is from leaks in the electricity industry.

Electrical company Eaton, which manufactures switchgear without SF6, says its research indicates that for the full life-cycle of the product, leaks could be as high as 15% - much higher than many other estimates.

Louis Schaeffer, electrical business manager at Eaton, said: "The newer gear has very low leak rates but the key question is do you have newer gear?

"We looked at all equipment and looked at the average of all those leak rates, and we didn't see people taking into account the filling of the gas. Plus, we looked at how you recycle it and return it and also included the catastrophic leaks."

How damaging to the climate is this gas?

Concentrations in the atmosphere are very small right now, just a fraction of the amount of CO2 in the air.

However, the global installed base of SF6 is expected to grow by 75% by 2030, as data-driven electricity demand surges worldwide.

Another concern is that SF6 is a synthetic gas and isn't absorbed or destroyed naturally. It will all have to be replaced and destroyed to limit the impact on the climate.

Developed countries are expected to report every year to the UN on how much SF6 they use, but developing countries do not face any restrictions on use.

Right now, scientists are detecting concentrations in the atmosphere that are 10 times the amount declared by countries in their reports. Scientists say this is not all coming from countries like India, China and South Korea.

One study found that the methods used to calculate emissions in richer countries "severely under-reported" emissions over the past two decades.

Why hasn't this been banned?

SF6 comes under a group of human-produced substances known as F-gases. The European Commission tried to prohibit a number of these environmentally harmful substances, including gases in refrigeration and air conditioning, back in 2014.

But they faced strong opposition from industries across Europe.

"In the end, the electrical industry lobby was too strong and we had to give in to them," said Dutch Green MEP Bas Eickhout, who was responsible for the attempt to regulate F-gases.

"The electric sector was very strong in arguing that if you want an energy transition, and you have to shift more to electricity, you will need more electric devices. And then you also will need more SF6.

"They used the argument that otherwise the energy transition would be slowed down."

What do regulator and electrical companies say about the gas?

Everyone is trying to reduce their dependence on the gas, and US control efforts suggest targeted policies can drive declines, as it is universally recognised as harmful to the climate.

In the UK, energy regulator Ofgem says it is working with utilities to try to limit leaks of the gas.

"We are using a range of tools to make sure that companies limit their use of SF6, a potent greenhouse gas, where this is in the interest of energy consumers," an Ofgem spokesperson told BBC News.

"This includes funding innovation trials and rewarding companies to research and find alternatives, setting emissions targets, rewarding companies that beat those targets, and penalising those that miss them."

Are there alternatives - and are they very expensive?

The question of alternatives to SF6 has been contentious over recent years.

For high-voltage applications, experts say there are very few solutions that have been rigorously tested.

"There is no real alternative that is proven," said Prof Manu Haddad from the school of engineering at Cardiff University.

"There are some that are being proposed now but to prove their operation over a long period of time is a risk that many companies don't want to take."

Medium voltage operations there are several tried-and-tested materials. Some in the industry say that the conservative nature of the electrical industry is the key reason that few want to change to a less harmful alternative.

"I will tell you, everyone in this industry knows you can do this; there is not a technical reason not to do it," said Louis Schaffer from Eaton.

"It's not really economic; it's more a question that change takes effort and if you don't have to, you won't do it."

Some companies are feeling the winds of change

Sitting in the North Sea some 43km from the Suffolk coast, Scottish Power Renewables has installed one of world's biggest wind farms, in line with a sustainable electric planet vision, where the turbines will be free of SF6 gas.

East Anglia One will see 102 of these towering generators erected, with the capacity to produce up to 714MW (megawatts) of power by 2020, enough to supply half a million homes.

Previously, an installation like this would have used switchgear supplied with SF6, to prevent the electrical accidents that can lead to fires.

Each turbine would normally have contained around 5kg of SF6, which, if it leaked into the atmosphere, would add the equivalent of around 117 tonnes of carbon dioxide. This is roughly the same as the annual emissions from 25 cars.

"In this case we are using a combination of clean air and vacuum technology within the turbine. It allows us to still have a very efficient, reliable, high-voltage network but to also be environmentally friendly," said Costa Pirgousis from Scottish Power Renewables.

"Once there are viable alternatives on the market, there is no reason not to use them. In this case, we've got a viable alternative and that's why we are using it."

But even for companies that are trying to limit the use of SF6, there are still limitations. At the heart of East Anglia One sits a giant offshore substation to which all 102 turbines will connect. It still uses significant quantities of the highly warming gas.

What happens next ?

The EU will review the use of SF6 next year and will examine whether alternatives are available. However, even the most optimistic experts don't think that any ban is likely to be put in place before 2025.

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100% Clean Energy Targets drive renewable electricity, decarbonization, and cost savings through state policies, CCAs, RECs, and mandates, with timelines and interim goals that boost jobs, resilience, and public health across cities, counties, and utilities.

Key Points

Policies for cities and states to reach 100% clean power by set dates, using mandates, RECs, and interim goals.

✅ Define eligible clean vs renewable resources

✅ Mandate vs goal framework with enforcement

✅ Timelines with interim targets and escape clauses

“An enormous amount of authority still rests with the states for determining your energy future. So we can build these policies that will become a postcard from the future for the rest of the country,” said David Hochschild, chair of the California Energy Commission, speaking last week at a UCLA summit on state and local progress toward 100 percent clean energy.

According to a new report from the UCLA Luskin Center for Innovation, 13 states, districts and territories, as well as more than 200 cities and counties, with standout clean energy purchases by Southeast cities helping drive momentum, have committed to a 100 percent clean electricity target — and dozens of cities have already hit it.

This means that one of every three Americans, or roughly 111 million U.S. residents representing 34 percent of the population, live in a community that has committed to or has already achieved 100 percent clean electricity, including communities like Frisco, Colorado that have set ambitious targets.

“We’re going to look back on this moment as the moment when local action and state commitments began to push the entire nation toward this goal,” said J.R. DeShazo, director of the UCLA Luskin Center for Innovation.

Not all 100 percent targets are alike, however. The report notes that these targets vary based on 1) what resources are eligible, 2) how binding the 100 percent target is, and 3) how and when the target will be achieved.

These distinctions will carry a lot of weight as the policy discussion shifts from setting goals to actually meeting targets. They also have implications for communities in terms of health benefits, cost savings and employment opportunities.

100% targets come in different forms

One key attribute is whether a target is based on "renewable" or "clean" energy resources. Some 100 percent targets, like Hawaii’s and Rhode Island’s 2030 plan, are focused exclusively on renewable energy, or sources that cannot be depleted, such as wind, solar and geothermal. But most jurisdictions use the broader term “clean energy,” which can also include resources like large hydroelectric generation and nuclear power.

States also vary in their treatment of renewable energy certificates, used to track and assign ownership to renewable energy generation and use. Unbundled RECs allow for the environmental attributes of the renewable energy resource to be purchased separately from the physical electricity delivery.

The binding nature of these targets is also noteworthy. Seven states, as well as Puerto Rico and the District of Columbia, have passed 100 percent clean energy transition laws. Of the jurisdictions that have passed 100 percent legislation, all but one specifies that the target is a “mandate,” according to the report. Nevada is the only state to call the target a “goal.”

Governors in four other states have signed executive orders with 100 percent clean energy goals.

Target timelines also vary. Washington, D.C. has set the most ambitious target date, with a mandate to achieve 100 percent renewable electricity by 2032. Other states and cities have set deadline years between 2040 and 2050. All "100 percent" state laws, and some city and county policies, also include interim targets to keep clean energy deployment on track.

In addition, some locations have included some form of escape clause. For instance, Salt Lake City, which last month passed a resolution establishing a goal of powering the county with 100 percent clean electricity by 2030, included “exit strategies” in its policy in order to encourage stakeholder buy-in, said Mayor Jackie Biskupski, speaking last week at the UCLA summit.

“We don’t think they’ll get used, but they’re there,” she said.

Other locales, meanwhile, have decided to go well beyond 100 percent clean electricity. The State of California and 44 cities have set even more challenging targets to also transition their entire transportation, heating and cooling sectors to 100 percent clean energy sources, and proposals like requiring solar panels on new buildings underscore how policy can accelerate progress across sectors.

Businesses are simultaneously electing to adopt more clean and renewable energy. Six utilities across the United States have set their own 100 percent clean or carbon-free electricity targets. UCLA researchers did not include populations served by these utilities in their analysis of locations with state and city 100 percent clean commitments.

“We cannot wait”

All state and local policies that require a certain share of electricity to come from renewable energy resources have contributed to more efficient project development and financing mechanisms, which have supported continued technology cost declines and contributed to a near doubling of renewable energy generation since 2008.

Many communities are switching to clean energy in order to save money, now that the cost calculation is increasingly in favor of renewables over fossil fuels, as more jurisdictions get on the road to 100% renewables worldwide. Additional benefits include local job creation, cleaner air and electricity system resilience due to greater reliance on local energy resources.

Another major motivator is climate change. The electricity sector is responsible for 28 percent of U.S. greenhouse gas emissions, second only to transportation. Decarbonizing the grid also helps to clean up the transportation sector as more vehicles move to electricity as their fuel source.

“The now-constant threat of wildfires, droughts, severe storms and habitat loss driven by climate change signals a crisis we can no longer ignore,” said Carla Peterman, senior vice president of regulatory affairs at investor-owned utility Southern California Edison. “We cannot wait and we should not wait when there are viable solutions to pursue now.”

Prior to joining SCE on October 1, Peterman served as a member of the California Public Utilities Commission, which implements and administers renewable portfolio standard (RPS) compliance rules for California’s retail sellers of electricity. California’s target requires 60 percent of the state’s electricity to come from renewable energy resources by 2030, and all the state's electricity to come from carbon-free resources by 2045.  

How CCAs are driving renewable energy deployment

One way California communities are working to meet the state’s ambitious targets is through community-choice aggregation, especially after California's near-100% renewable milestone underscored what's possible, via which cities and counties can take control of their energy procurement decisions to suit their preferences. Investor-owned utilities no longer purchase energy for these jurisdictions, but they continue to operate the transmission and distribution grid for all electricity users.                           

A second paper released by the Luskin Center for Innovation in recent days examines how community-choice aggregators are affecting levels of renewable energy deployment in California and contributing to the state’s 100 percent target.

The paper finds that 19 CCAs have launched in California since 2010, growing to include more than 160 towns, cities and counties. Of those communities, 64 have a 100 percent renewable or clean energy policy as their default energy program.

Because of these policies, the UCLA paper finds that “CCAs have had both direct and indirect effects that have led to increases in the clean energy sold in excess of the state’s RPS.”

From 2011 to 2018, CCAs directly procured 24 terawatt-hours of RPS-eligible electricity, 11 TWh of which have been voluntary or in excess of RPS compliance, according to the paper.

The formation of CCAs has also had an indirect effect on investor-owned utilities. As customers have left investor-owned utilities to join CCAs, the utilities have been left holding contracts for more renewable energy than they need to comply with California’s clean energy targets, amid rising solar and wind curtailments that complicate procurement decisions. UCLA researchers estimate that this indirect effect of CCA formation has left IOUs holding 13 terawatt-hours in excess of RPS requirements.

The paper concludes that CCAs have helped to accelerate California’s ability to meet state renewable energy targets over the past decade. However, the future contributions of CCAs to the RPS are more uncertain as communities make new power-purchasing decisions and utilities seek to reduce their excess renewable energy contracts.

“CCAs offer a way for communities to put their desire for clean energy into action. They're growing fast in California, one of only eight states where this kind of mechanism is allowed," said UCLA's Kelly Trumbull, an author of the report. "State and federal policies could be reformed to better enable communities to meet local demand for renewable energy.”

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White Pines Project cancellation highlights Ontario's wind farm contract dispute in Prince Edward County, involving IESO approvals, Progressive Conservatives' legislation, potential court action, and costs to ratepayers amid green energy policy shifts.

Key Points

The termination effort for Ontario's White Pines wind farm contract, triggering legal, legislative, and cost disputes.

✅ Contract with IESO dates to 2009; final approval during election

✅ PCs seek legislation insulating taxpayers from litigation

✅ Cancellation could exceed $100M; cost impact on ratepayers

Cancelling an eastern Ontario green energy project that has been under development for nearly a decade could cost more than $100 million, the president of the company said Wednesday, warning that the dispute could be headed to the courts.

Ontario's governing Progressive Conservatives said this week that one of their first priorities during the legislature's summer sitting would be to cancel the contract for the White Pines Project in Prince Edward County.

Ian MacRae, president of WPD Canada, the company behind the project, said he was stunned by the news given that the project is weeks away from completion.

"What our lawyers are telling us is we have a completely valid contract that we've had since 2009 with the (Independent Electricity System Operator). ... There's no good reason for the government to breach that contract," he said.

The government has also not reached out to discuss the cancellation, he said. Meanwhile, construction on the site is in full swing, he said.

"Over the last couple weeks we've had an average of 100 people on site every day," he said. "The footprint of the project is 100 per cent in. So, all the access roads, the concrete for the base foundations, much of the electrical infrastructure. The sub-station is nearing completion."

The project includes nine wind turbines meant to produce enough electricity to power just over 3,000 homes annually, even as Ontario looks to build on an electricity deal with Quebec for additional supply. All of the turbines are expected to be installed over the next three weeks, with testing scheduled for the following month.

MacRae couldn't say for certain who would have to pay for the cancellation, electricity ratepayers or taxpayers.

"Somehow that money would come from IESO and it would be my assumption that would end up somehow on the ratepayers, despite legislation to lower electricity rates now in place," he said. "We just need to see what the government has in mind and who will foot the bill."

Progressive Conservative house leader Todd Smith, who represents the riding where the project is being built, said the legislation to cancel the project will also insulate taxpayers from domestic litigation over the dismantling of green energy projects.

"This is something that the people of Prince Edward County have been fighting ... for seven years," he said. "This shouldn't have come as a surprise to anybody that this was at the top of the agenda for the incoming government, which has also eyed energy independence in recent decisions."

Smith questioned why Ontario's Independent Electricity System Operator gave the final approval for the project during the spring election campaign.

"There's a lot of questions about how this ever got greenlighted in the first place," he said. "This project was granted its notice to proceed two days into the election campaign ... when (the IESO) should have been in the caretaker mode."

Terry Young, the IESO's vice president of policy, engagement and innovation, said the agency could not comment because of the pending introduction of legislation to cancel the deal, following a recent auditor-regulator dispute that drew attention to oversight.

NDP Leader Andrea Horwath said the new Tory government is behaving like the previous Liberal government by cancelling energy projects and tearing up contracts amid ongoing debates over Ontario's hydro mess and affordability. She likened the Tory plan to the Liberal gas plant scandal that saw the government relocate two plants at a substantial cost to taxpayers.

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Quebec EV transition plan aims for 2 million electric vehicles by 2030 and bans new gas cars by 2035, stressing charging infrastructure, incentives, emissions cuts, and industry impacts, with debate over feasibility and economic risks.

Key Points

A provincial policy targeting 2M EVs by 2030 and a 2035 gas-car sales ban, backed by charging buildout and incentives.

✅ Requires major charging infrastructure and grid upgrades

✅ Balances incentives with economic impacts and industry readiness

✅ Gas stations persist while EV adoption accelerates cautiously

Quebec's ambitious push to dominate the electric vehicle (EV) market, echoing Canada's EV goals in its plan, by setting a target of two million EVs on the road by 2030 and planning to ban the sale of new gas-powered vehicles by 2035 has sparked significant debate among industry experts. While the government's objectives aim to reduce greenhouse gas emissions and promote sustainable transportation, some experts question the feasibility and potential economic impacts of such rapid transitions.

Current Landscape of Gas Stations in Quebec

Contrary to Environment Minister Benoit Charette's assertion that gas stations may become scarce within the next decade, industry experts suggest that the number of gas stations in Quebec is unlikely to decline drastically. Carol Montreuil, Vice President of the Canadian Fuels Association, describes the minister's statement as "wishful thinking," emphasizing that the number of gas stations has remained relatively stable over the past decade. Statistics indicate that in 2023, Quebec residents purchased more gasoline than ever before, and EV shortages and wait times further underscore the continued demand for traditional fuel sources.

Challenges in Accelerating EV Adoption

The government's goal of having two million EVs on Quebec roads by 2030 presents several challenges. Currently, there are approximately 200,000 fully electric cars in the province. Achieving a tenfold increase in less than a decade requires substantial investments in charging infrastructure, consumer incentives, and public education to address concerns such as range anxiety and charging accessibility, especially amid electricity shortage warnings across Quebec and other provinces.

Economic Considerations and Industry Concerns

Industry stakeholders express concerns about the economic implications of rapidly phasing out gas-powered vehicles. Montreuil warns that the industry is already struggling and that attempting to transition too quickly could lead to economic challenges, a view echoed by critics who label the 2035 EV mandate delusional. He suggests that the government may be spending excessive public funds on subsidies for technologies that are still expensive and not yet widely adopted.

Public Sentiment and Adoption Rates

Public sentiment towards EVs is mixed, and experiences in Manitoba suggest the road to targets is not smooth. While some consumers, like Montreal resident Alex Rajabi, have made the switch to electric vehicles and are satisfied with their decision, others remain hesitant due to concerns about vehicle cost, charging infrastructure, and the availability of incentives. Rajabi, who transitioned to an EV nine months ago, notes that while he did not take advantage of the incentive program, he is happy with his decision and suggests that adding charging ports at gas stations could facilitate the transition.

The Need for a Balanced Approach

Experts advocate for a balanced approach that considers the pace of technological advancements, consumer readiness, and economic impacts. While the transition to electric vehicles is essential for environmental sustainability, it is crucial to ensure that the infrastructure, market conditions, and public acceptance are adequately addressed, and to recognize that a share of Canada's electricity still comes from fossil fuels, to make the shift both feasible and beneficial for all stakeholders.

In summary, Quebec's ambitious EV targets reflect a strong commitment to environmental sustainability. However, industry experts caution that achieving these goals requires careful planning, substantial investment, and a realistic assessment of the challenges involved as federal EV sales regulations take shape, in transitioning from traditional vehicles to electric mobility.

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Germany Industrial Electricity Price Subsidy weighs subsidies for energy-intensive industries to bolster competitiveness as Germany shifts to renewables, expands grid capacity, and debates free-market tax cuts versus targeted relief and long-term policies.

Key Points

Policy to subsidize power for energy-intensive industry, preserving competitiveness during the energy transition.

✅ SPD backs 5-7 cents per kWh for 10-15 years

✅ FDP prefers tax cuts and free-market pricing

✅ Scholz urges cheap renewables and grid expansion first

Germany’s three-party coalition is debating whether electricity prices for energy-intensive industries should be subsidised in a market where rolling back European electricity prices can be tougher than it appears, to prevent companies from moving production abroad.

Calls to reduce the electricity bill for big industrial producers are being made by leading politicians, who, like others in Germany, fear the country could lose its position as an industrial powerhouse as it gradually shifts away from fossil fuel-based production, amid historic low energy demand and economic stagnation concerns.

“It is in the interest of all of us that this strong industry, which we undoubtedly have in Germany, is preserved,” Lars Klingbeil, head of Germany’s leading government party SPD (S&D), told Bayrischer Rundfunk on Wednesday.

To achieve this, Klingbeil is advocating a reduced electricity price for the industry of about 5 to 7 cents per Kilowatt hour, which the federal government would subsidise. This should be introduced within the next year and last for about 10 to 15 years, he said.

Under the current support scheme, which was financed as part of the €200 billion “rescue shield” against the energy crisis, energy-intensive industries already pay 13 cents per Kilowatt hour (KWh) for 70% of their previous electricity needs, which is substantially lower than the 30 to 40 cents per KWh that private consumers pay.

“We see that the Americans, for example, are spending $450 billion on the Inflation Reduction Act, and we see what China is doing in terms of economic policy,” Klingbeil said.

“If we find out in 10 years that we have let all the large industrial companies slip away because the investments are not being made here in Germany or Europe, and jobs and prosperity and growth are being lost here, then we will lose as a country,” he added.

However, not everyone in the German coalition favours subsidising electricity prices.

Finance Minister Christian Lindner of the liberal FDP (Renew), for example, has argued against such a step, instead promoting free-market principles and, amid rising household energy costs, reducing taxes on electricity for all.

“Privileging industrial companies would only be feasible at the expense of other electricity consumers and taxpayers, for example, private households or the small trade sector,” Lindner wrote in an op-ed for Handelsblatt on Tuesday.

“Increasing competitiveness for some would mean a loss of competitiveness for others,” he added.

Chancellor Olaf Scholz, himself a member of SPD, was more careful with his words, amid ongoing EU electricity reform debates in Brussels.

Asked about a subsidised electricity price for the industry at a town hall event on Monday, Scholz said he does not “want to make any promises now”.

“First of all, we have to make sure that we have cheap electricity in Germany in the first place,” Scholz said, promoting the expansion of renewable energy such as wind and solar, as local utilities cry for help, as well as more electricity grid infrastructure.

“What we will not be able to do as an economy, even as France’s new electricity pricing scheme advances, is to subsidise everything that takes place in normal economic activity,” Scholz said. “We should not get into the habit of doing that,” he added.

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CO2 Removal Technologies address climate change via negative emissions, including carbon capture, reforestation, soil carbon, biochar, BECCS, DAC, and mineralization, helping meet Paris Agreement targets while managing costs, land use, and infrastructure demands.

Key Points

Methods to extract or sequester atmospheric CO2, combining natural and engineered approaches to limit warming.

✅ Includes reforestation, soil carbon, biochar, BECCS, DAC, mineralization

✅ Balances climate goals with costs, land, energy, and infrastructure

✅ Key to Paris Agreement targets under 1.5-2.0 °C warming

The world is, on average, 1.1 degrees Celsius warmer today than it was in 1850. If this trend continues, our planet will be 2 – 3 degrees hotter by the end of this century, according to the Intergovernmental Panel on Climate Change (IPCC).

The main reason for this temperature rise is higher levels of atmospheric carbon dioxide, which cause the atmosphere to trap heat radiating from the Earth into space. Since 1850, the proportion of CO2 in the air has increased, with record greenhouse gas concentrations documented, from 0.029% to 0.041% (288 ppm to 414 ppm).

This is directly related to the burning of coal, oil and gas, which were created from forests, plankton and plants over millions of years. Back then, they stored CO2 and kept it out of the atmosphere, but as fossil fuels are burned, that CO2 is released. Other contributing factors include industrialized agriculture and slash-and-burn land clearing techniques, and emissions from SF6 in electrical equipment are also concerning today.

Over the past 50 years, more than 1200 billion tons of CO2 have been emitted into the planet's atmosphere — 36.6 billion tons in 2018 alone, though global emissions flatlined in 2019 before rising again. As a result, the global average temperature has risen by 0.8 degrees in just half a century.

Atmospheric CO2 should remain at a minimum
In 2015, the world came together to sign the Paris Climate Agreement which set the goal of limiting global temperature rise to well below 2 degrees — 1.5 degrees, if possible.

The agreement limits the amount of CO2 that can be released into the atmosphere, providing a benchmark for the global energy transition now underway. According to the IPCC, if a maximum of around 300 billion tons were emitted, there would be a 50% chance of limiting global temperature rise to 1.5 degrees. If CO2 emissions remain the same, however, the CO2 'budget' would be used up in just seven years.

According to the IPCC's report on the 1.5 degree target, negative emissions are also necessary to achieve the climate targets.

Using reforestation to remove CO2
One planned measure to stop too much CO2 from being released into the atmosphere is reforestation. According to studies, 3.6 billion tons of CO2 — around 10% of current CO2 emissions — could be saved every year during the growth phase. However, a study by researchers at the Swiss Federal Institute of Technology, ETH Zurich, stresses that achieving this would require the use of land areas equivalent in size to the entire US.

Young trees at a reforestation project in Africa (picture-alliance/OKAPIA KG, Germany)
Reforestation has potential to tackle the climate crisis by capturing CO2. But it would require a large amount of space

More humus in the soil
Humus in the soil stores a lot of carbon. But this is being released through the industrialization of agriculture. The amount of humus in the soil can be increased by using catch crops and plants with deep roots as well as by working harvest remnants back into the ground and avoiding deep plowing. According to a study by the German Institute for International and Security Affairs (SWP) on using targeted CO2 extraction as a part of EU climate policy, between two and five billion tons of CO2 could be saved with a global build-up of humus reserves.

Biochar shows promise
Some scientists see biochar as a promising technology for keeping CO2 out of the atmosphere. Biochar is created when organic material is heated and pressurized in a zero or very low-oxygen environment. In powdered form, the biochar is then spread on arable land where it acts as a fertilizer. This also increases the amount of carbon content in the soil. According to the same study from the SWP, global application of this technology could save between 0.5 and two billion tons of CO2 every year.

Storing CO2 in the ground
Storing CO2 deep in the Earth is already well-known and practiced on Norway's oil fields, for example. However, the process is still controversial, as storing CO2 underground can lead to earthquakes and leakage in the long-term. A different method is currently being practiced in Iceland, in which CO2 is sequestered into porous basalt rock to be mineralized into stone. Both methods still require more research, however, with new DOE funding supporting carbon capture, utilization, and storage.

Capturing CO2 to be held underground is done by using chemical processes which effectively extract the gas from the ambient air, and some researchers are exploring CO2-to-electricity concepts for utilization. This method is known as direct air capture (DAC) and is already practiced in other parts of Europe.  As there is no limit to the amount of CO2 that can be captured, it is considered to have great potential. However, the main disadvantage is the cost — currently around €550 ($650) per ton. Some scientists believe that mass production of DAC systems could bring prices down to €50 per ton by 2050. It is already considered a key technology for future climate protection.

The inside of a carbon capture facility in the Netherlands (RWE AG)
Carbon capture facilities are still very expensive and take up a huge amount of space

Another way of extracting CO2 from the air is via biomass. Plants grow and are burned in a power plant to produce electricity. CO2 is then extracted from the exhaust gas of the power plant and stored deep in the Earth, with new U.S. power plant rules poised to test such carbon capture approaches.

The big problem with this technology, known as bio-energy carbon capture and storage (BECCS) is the huge amount of space required. According to Felix Creutzig from the Mercator Institute on Global Commons and Climate Change (MCC) in Berlin, it will therefore only play "a minor role" in CO2 removal technologies.

CO2 bound by rock minerals
In this process, carbonate and silicate rocks are mined, ground and scattered on agricultural land or on the surface water of the ocean, where they collect CO2 over a period of years. According to researchers, by the middle of this century it would be possible to capture two to four billion tons of CO2 every year using this technique. The main challenges are primarily the quantities of stone required, and building the necessary infrastructure. Concrete plans have not yet been researched.

Not an option: Fertilizing the sea with iron
The idea is use iron to fertilize the ocean, thereby increasing its nuturient content, which would allow plankton to grow stronger and capture more CO2. However, both the process and possible side effects are very controversial. "This is rarely treated as a serious option in research," concludes SWP study authors Oliver Geden and Felix Schenuit.

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