How to address the climate crisis — one tonne of carbon at a time

How to address the climate crisis — one tonne of carbon at a time

Here’s the low-down on carbon dioxide removal credits, what they do and why they’re a vital tool in the fight against climate change.

Climate change is no longer an invisible boogeyman — extreme weather events and intense heat waves are happening with increasing frequency. And yet, we’re still pumping greenhouse gases in ever-growing amounts into the atmosphere. Emissions rose by 1.1 percent in 2023, reaching a record-breaking 37.4 billion tonnes. But even if we went cold turkey with fossil fuel products tomorrow, heat stored in the ocean would continue to rise to the surface, heating up our atmosphere for several decades. That means, things are bound to get worse before they get better. To hit 2050 net-zero targets (not to mention keep our planet hospitable to human life), we have to remove the excess carbon that already exists in the atmosphere, along with emissions that will continue to be created.

Alongside massive reductions in emissions, new tools are needed. Hard-to-abate emitters, like industrial sectors, agriculture, aviation and shipping will have a harder time converting to renewable energy. “We’ll need multiple ways to pull that carbon from the atmosphere and lock it away for hundreds or thousands of years,” says Andy Lam, a senior manager on the MaRS climate team. “We need to develop technologies and create policies to help scale the carbon dioxide removal (CDR) sector.” The nascent-but-fast-growing CDR market still has a lot to figure out, and scaling projects is going to require investment.

This is why MaRS is putting its money where its carbon is and is purchasing CDR credits worth $60,000 from five Canadian startups working on removing carbon from the atmosphere. The methods these startups are using vary widely: CarbonRun restores pH balance to overly acidified rivers by introducing limestone, which causes the waterways to absorb more carbon; Planetary Technologies also works on deacidification but in oceans rather than rivers; Gaia Refinery uses direct air capture and biomass technology to suck up carbon from the atmosphere and store it permanently; Arca reprocesses mine tailings to accelerate their transformation into minerals that lock in carbon; and TerraFixing specializes in direct air capture in cold climates.

As one of the first Canadian charitable organizations to buy carbon removal credits, MaRS aims to kick-start the market, while also offsetting emissions from the annual MaRS Climate Impact conference. This purchase also shows that carbon credits aren’t exclusively for the Googles and J.P. Morgans out there. Investment from big corporations is necessary for startups developing transformative tech, but the door to Canada’s CDR market is open to NGOs and small businesses, too. But where is the carbon market at now in Canada? Why is this country a natural fit for CDR solutions? How do you join in and make sure carbon is actually being removed from the atmosphere?

Let’s dive into what these credits are and how they can help the climate keep its cool.


What exactly are carbon removal credits?

First off: a single carbon credit equals one tonne of carbon removed from the atmosphere and stored in a new form, for hundreds or thousands of years. A company or individual can buy credits from an environmentally-focused company via an advisory firm, broker or directly from their website. The five companies chosen by MaRS are changing carbon dioxide from a gas into an inert state, such as using biomass to capture carbon dioxide directly from the air, introducing alkaline substances into rivers to make them less acidic and capable of absorbing more carbon dioxide or reprocessing mine tailings to accelerate the mineralization process. These practices all remove carbon and permanently store it, leading to a net reduction in the amount of carbon in the atmosphere. Companies sell the quantifiable carbon removal created by their endeavours.


Scientists from Dalhousie University are gathering data to measure the impact of Planetary Technologies’ ocean alkalinity project in Halifax Harbour.
Photo credit: Planetary Technologies


Why do we need to remove carbon from the atmosphere?

It’s important to highlight that companies and corporations have a lot of work to do in cutting their emissions, but many big industrial processes are hard to abate and they will continue to emit considerably for years to come. CDR is needed to help address those emissions as well as what we’ve already released into the atmosphere. However, CDR is not a silver-bullet solution, and it will suffer from being labelled as greenwashing if it’s treated as such. “Right now, carbon removal is looked at favourably by outsiders. If we were to lose that, then that would be catastrophic,” highlights Mitchel Selby, who leads Shopify’s sustainability fund. According to the IPCC’s 2023 report, CDRs have a considerable role to play in achieving net zero, since they’re a must for decarbonizing unavoidable emissions from big polluters.

Arca reprocesses mine tailings to accelerate their transformation into minerals that perpetually lock in carbon.


How are carbon removal credits different from carbon offsets?

There’s a big difference between removal credits and traditional offsets, and they often get jumbled. “A lot of carbon offsets don’t tackle atmospheric carbon dioxide. A lot of them are carbon avoidance, like buying more efficient stoves or supporting forest conservation,” explains Lam. An offset project might ensure that a forest doesn’t get chopped down (meaning the carbon contained therein stays trapped), whereas the CDR credit-selling company Arca is developing technology that reprocesses mine tailings to speed up mineralization, which permanently captures carbon from the atmosphere. Though avoidance is not what these companies are doing, it’s important to stress that both removal and avoidance provide a positive impact on the planet. While carbon removal can directly affect the total carbon count, many avoidance offsets can support biodiversity and protect resources through conservation.


What should you look for when considering a CDR purchase?

When Selby is looking to buy CDR credits for Shopify, he has a solid list of considerations to run through. High on the list is the tech’s potential to grow, ensuring projects can make a significant dent in the climate problem. The processes need to also be low-cost once they’re at scale and make a quantifiable impact — they need to be actually removing carbon dioxide from the atmosphere in a measurable way and storing it permanently. (CarbonRun traps carbon for an estimated 90,000 years, unlike many nature-based solutions in which trees can burn down in wildfires or kelp forests can be destroyed by warming waters.)

Accountability via data reporting is also paramount. “Before we buy, we need to know that credits are verifiable, and that there’s a strategy and plan for tracking credits, whether it’s sensors in the water up and downstream or monitoring the carbon dioxide being absorbed,” explains Lam. Crucially, CDR credits need to be additional, so not something a company has already done or was going to do anyway, and the credits need to be net negative, meaning they remove more carbon dioxide than the process creates.

Last but not least, projects need to respect the communities in which they’re deployed. Community engagement and working with Indigenous groups is important, so that they are included in the emerging market and able to apply their knowledge about the land in these projects. Halifax-based CarbonRun is currently aiming to improve biodiversity in the West River of Pictou, N.S., and is being guided by the knowledge of local river groups and the Pictou First Nation about the waterway.


How do you buy credits anyway?

Most carbon removal purchases are made by companies looking to buy a considerable sum of credits rather than individuals, says Selby. However, some selling companies have credits open to anyone through their websites. Your first step is to shop around. Once you’ve found a company that meets your criteria, you can work together on an agreement that details pricing, how many credits they have available and a timeline for the CDR process. After all the i’s are dotted and t’s are crossed, the company gets to work, removing carbon dioxide on your behalf.

For example, by releasing crushed limestone into a river via a sensor-equipped lime doser to make water less acidic, CarbonRun sparks a chemical reaction that absorbs carbon. Over the next three years, CarbonRun will remove purchased tonnes from the atmosphere through their alkalization operations and then, once that process is complete for their sold credits, they will sell new credits. Though the total amount of carbon absorption always varies depending on a river’s chemical and hydrological conditions, in ideal conditions, the company expects to remove 0.48 tonnes of carbon dioxide for every tonne of limestone dissolved.


How is this stuff monitored?

There’s still some skepticism surrounding the transparency of CDR and offset markets, but the two shouldn’t get lumped together. CDR projects typically have rigorous third-party verification organizations checking their data and output, so they’re closely monitored and held to established standards, like the Gold Standard voluntary carbon credit certification program.

Offsets and credits can get labelled as an option that allows corporations to take the easy way out by paying others to do their carbon-stained laundry. Timothy Bushman, the director of policy and research at the NGO Carbon Removal Canada (CRC), explains that standards are still being developed. For now, a lot of verification is done via protocols developed for projects by carbon credit certification platforms, such as Isometric whose mission is to rebuild trust in carbon markets.

“We have an ISO-compliant protocol, through which we monitor the carbon drawdown and removal in rivers,” says Eddie Halfyard, the co-founder and CTO of CarbonRun. “Our field crew uses relatively simple sensors. They put them in the water, and we get a data point every 15 minutes. We’re developing systems where that’s all integrated in a network, given to us in real-time data. We can basically look at an interface and say ‘Hey, look how much carbon we drew down this past hour.’” The data then gets used in two ways: The original raw data is kept in a repository where it can’t be altered, and another version undergoes a quality control protocol to test for errors and statistical outliers. This so-called clean version can then fill gaps in CarbonRun’s data and be used for calculating CDR.


What’s the deal with credit pricing?

“The spectrum is crazy,” says Bushman. Prices range anywhere from around $40 a tonne to well into the thousands. We see reforestation projects in that lower range, then things like biomass pyrolysis to create biofuel in the hundreds. In the upper range, you’ll find direct air capture projects or ocean alkalinity enhancement. “Those very first-of-a-kind projects, those are running up to or in excess of $1,000 per tonne,” says Bushman. “The companies are having to build tech from zero with these.” However, prices are set to drop with more money expected to flow into the sector from governments, and as the technology scales and gets cheaper to produce. “Energy prices are going to play a big role, too. If energy prices come down because supply of renewable energy increases, then that’s going to have an impact on the price of these credits,” says Selby.

The price also represents the amount of effort that went into creating the project. Halfyard gives partial props to the natural mixing in rivers that happens thanks to the force of rushing water for their $387 per tonne price point, which he anticipates will decrease in the coming years. “The river does a lot of the work for us — mixing and transporting the carbon to the ocean. It’s a really beautiful system,” he says.


Where is the Canadian CDR market at?

While Canada is behind the U.S. and EU when it comes to building a CDR market, the industry is predicted to create 300,000 jobs and $143 billion in this country by 2050, partially because much of our expansive and diverse geography lends itself well to CDR projects. For instance, TerraFixing has developed the first direct air capture that can be deployed in the Arctic.


Where do we go from here?

CDR can be an abstract concept for many — transferring mass from the atmosphere and putting it somewhere else in another state can sound like something straight out of sci-fi. It can help to highlight the non-carbon benefits of these projects. “Companies that have a better story to tell and tell it effectively are going to be at an advantage in the market,” says Bushman. For instance, CarbonRun’s technology helps improve biodiversity in waterways, and Gaia’s method uses biomass instead of heat, so they are able to capture carbon dioxide with minimal energy.

To enable companies to remove carbon from the atmosphere, we’re going to need cash flow, says Bushman. “Going from demo to pilot to commercial scale to multiple commercial scales, they’re going to need a lot of project financing. We need policy-makers to care about this.” CRC’s 2023 report states that Canada will need at least 300 megatonnes of carbon removal capacity by 2050 to compensate for hard-to-abate sectors and start removing our historical emissions. “Policy can definitely help,” says Selby. “Regardless of how the voluntary market plays out over the next couple of years, the only way this industry scales is if governments introduce policies to support it.”

Based on MaRS’ purchase of carbon removal credits from five Canadian ventures, the Pembina Institute developed an educational report in collaboration with MaRS to act as a resource guide for those looking to become buyers in the carbon market and support responsible CDR development in Canada. Read the report to learn more. 

Main image source: iStock