12-22 Forsterite olivine

[Image above] Olivine, a silicate mineral that is highly abundant on earth—and may be the next big thing in effective and scalable carbon capture and storage techniques. Credit: James St. John, Flickr (CC BY 2.0)

As 2020 winds to a close, I can’t help but reflect on what a year it’s been.

If your experience has been anything like mine, the calendar year that is closing looks drastically different than the one that began eons ago in a time called January. I haven’t seen most of my family or friends (in person) in the better part of a year, far-flung travel plans and much more have been canceled, videoconferences became a regular part of life, and I have a starter culture of microbes constantly bubbling away on my counter (sourdough forever!). The world changed in many different ways, and I’m sure I changed as well.

In the ups, downs, tragedies, and triumphs of the year, it is hard not to reflect on all that’s been lost in 2020—lives, jobs, peace of mind, hope, plans, a sense of normalcy. 

The year has been challenging, and it’s surely been marred by disappointment, sacrifice, and grief.

While I acknowledge these challenges and negative attributes that 2020 carried with her, I also acknowledge that the year wasn’t all bad. We’ve innovated new ways to adapt and pivot to a new normal; we’ve come together to provide support when it’s needed; we’ve perhaps learned to appreciate the small things a little bit better than before. I surely won’t take a hug for granted anytime in the near future.

But I’m taking an entirely human-centered view here—the pandemic also had positive impacts on the natural world as well.

We saw it early in the pandemic, as wild animals were seen taking back the streets, roaming free while humans were locked inside their houses.

And recent analyses by the Global Carbon Project indicate that all our canceled plans and confinement to our homes in 2020 compounded into a 7% worldwide drop in fossil carbon emissions from 2019.

“I think it’s likely the biggest [drop in emissions] ever,” Rob Jackson, Stanford University earth scientist and chair of the Global Carbon Project, says in a Popular Science article. “That’s the equivalent of taking about 500 million cars off the world’s roads for a year.” 

That’s impressive. But when it comes to carbon emissions, it is still not enough. 

Simply cutting current and future carbon emissions, even drastically, will not be enough to reverse the damage that’s already been done and prevent further climate change and environmental damage. Instead, we need additional strategies to help dig us out of the hole we’ve created, and one popular option currently is capture carbon and storage.

These methods and techniques widely vary, from high-tech to entirely natural, but the principle is the same—to capture carbon dioxide formed from industrial processes and fossil fuel-based activities and store it, so that it doesn’t further contribute to atmospheric levels. Some of the strategies even turn that carbon dioxide into a usable product such as fuel (those strategies are termed carbon capture, utilization, and storage).

One industry that certainly has been under a harsh spotlight is the cement industry, due to its 7% contribution to global carbon dioxide emissions. Accordingly, the cement industry has increasingly looked at ways to reduce its negative environmental impact, including not only “greener” cement formulations but also production facilities that capture carbon before it is released into the atmosphere.

Another significant contributor to carbon emissions is the transportation industry, which is estimated to account for 28.2% of carbon emissions in the United States in 2018. In addition to fossil fuel burning vehicles on the roads, air travel accounts for a large amount of those emissions, so many airlines are now similarly looking for ways to reduce their environmental impact.

Again, carbon capture techniques offer a solution. For instance, United Airlines recently announced that it plans to reduce its carbon emissions 100% by 2050 by investing in carbon capture technologies. Its strategy involves a multimillion-dollar investment in a company called 1PointFive, which uses large facilities to literally suck carbon dioxide from the air, a process generally termed direct air capture.

But while such carbon capture solutions generally are seen as a necessary component of our sustainable future, the problem is that these technologies and strategies are often expensive to implement—the economics still are not favorable to encourage and expand their use enough to sufficiently address the problem.

So what is really needed is a strategy that is not only effective at removing carbon dioxide from the air but also is scalable, affordable, and easy to implement across the globe.

A simple green silicate mineral called olivine just might provide the solution.

At least that’s what a recent initiative called Project Vesta is pursuing. The Project describes itself as “a nature-based, permanent, scalable, and affordable solution to climate change,” and that solution involves using olivine to enhance the earth’s natural process of carbon sequestration. 

Project Vesta’s idea is relatively simple yet clever—mimic the earth’s natural process of carbon sequestration but enhance the process, speeding it up to keep pace with human activity. “Our mission is to help reverse climate change by turning a trillion tonnes of CO2 into rock,” the Project’s website states.

To understand the project’s strategy, it helps to understand the process by which the earth normally sequesters carbon dioxide, called the carbon-silicate cycle or the inorganic carbon cycle. This natural cycle incorporates weathering of rock and volcanic activity, which sequester and release carbon dioxide, respectively—converse processes that roughly balance one another to keep the earth’s atmosphere at a relative carbon dioxide status quo.

The basic gist is that weathering of rocks draws carbon dioxide out of the atmosphere and incorporates it into the rocks, which are eventually drawn down into the earth’s mantle via movement of the tectonic plates. There, heat and pressure catalyze chemical reactions that release the carbon dioxide, which is then burped back out into the atmosphere during volcanic eruptions, restarting the cycle.

The carbonate-silicate cycle. Credit: John Garrett, Wikimedia (CC BY-SA 3.0)

The cycle normally works to balance out the earth’s atmospheric carbon dioxide content, but the problem is humans—we have altered the natural landscapes to such an extent and contributed so much additional carbon dioxide to the atmosphere through activities like burning fossil fuels that the earth cannot keep up. 

So Project Vesta’s idea is to enhance this natural process, essentially jump starting the carbonate-silicate cycle to augment the earth’s ability to sequester all that excess carbon dioxide created by human activity. The project’s solution—termed coastal enhanced weathering—involves mining, crushing, and spreading a mineral called olivine on beaches. 

“Olivine is a widely abundant volcanic mineral. It makes up over 50% of the Earth’s upper mantle, and is the most effective mineral for enabling CO2 removal through rock weathering,” the Project’s website states. 

During weathering, olivine reacts with water, generating hydroxide ions that react with carbon dioxide in the atmosphere. The bicarbonate that forms from this reaction washes into oceans, through the action of waves, and precipitates as carbonate onto the ocean floor. There, the carbon dioxide is locked into rock that will eventually be drawn down into the earth via movement of tectonic plates, effectively sequestering carbon dioxide deep in the earth.

Project Vesta isn’t looking to turn all beaches green with olivine—the project estimates just 2% of shelf seas (oceans on the continental shelf, where there is high mixing of waters) are needed to capture all carbon emissions spewed out by human activity.

And at a cost of as little as $21/tonne—which the project says, at full scale, amounts to less than 10% the cost of other carbon capture strategies—enhanced coastal weathering is economically feasible as well.

Because olivine is one of the most common minerals on earth by volume, supply shouldn’t be an issue either. And while mining, crushing, and transporting olivine to beaches will certainly contribute its own carbon emissions, the scaled process, if successful, will more than offset its damage. Project Vesta states that the process is 95% efficient—for every tonne of CO2 emitted during olivine extraction and transportation, enhanced coastal weathering with that olivine can remove 20 tonnes of COfrom the atmosphere.

It all sounds quite promising—but the big question is, will it work?

Project Vesta currently is testing pilot-scale experiments, incrementally adding crushed olivine to a test beach to monitor how it affects the total environment. If they see positive results, the team plans to extend the testing to additional environments to ensure scalability and safety of the strategy, scaling up incrementally and continuing to monitor the effects before eventually rolling out a global strategy.

The project reminds of the current situation with the global pandemic, where the promise of highly effective vaccines is offering a glimmer of hope to restore some sense of balance to the world. 

Now, we just have to wait and see if it all pans out.

Find more of the science behind Project Vesta’s strategy here.