We're going to go ahead and assume that if you’re here, you know that climate change is caused by us humans emitting too many greenhouse gases, mostly CO₂, into the atmosphere. If not, feel free to learn more here.
You might also be aware that climate change poses a whole host of problems, from sea level rise to extreme weather events to a multitude of negative health impacts for virtually all life on our planet.
How to remove CO2 from air?
We see three main approaches to solving problems associated with Climate Change:
Efforts that help stop causing the problem and making it worse. These efforts usually fall under the terms "Emissions Reductions" or "Decarbonization", because they reduce or eliminate the carbon emissions from a given activity.
Efforts that help societies adapt to changes in the climate. These efforts fall under the term "Adaptation", and we are going to need them as our world changes.
Efforts that help reverse the problem we have already created. Because changes in the climate stem directly from excess greenhouse gas emissions into the atmosphere, a large part of the solution is to remove them so they can no longer continue to heat the planet. These efforts fall under the broader term "Greenhouse Gas Removal and Storage".
We are focused on the third approach - reverse - specifically on the removal of one greenhouse gas, CO₂, because it presents the biggest problem long term.
CDR also contains plenty of both accessible and desirable solutions, from reforestation and soil sequestration, to capturing CO₂ from the air with machines and storing it permanently underground, to mineralizing industrial wastes, making them less hazardous.
Something for everyone. ☺️
The Scale of the Problem
In order to keep global temperature rise between 1.5°C and 2°C, we are going to need to remove GIGATONS of CO₂ - much more CDR than is currently possible.
Did you know that the 2020 COVID lockdowns reduced global fossil fuel emissions by only 7%?
Imagine how hard it is going to be to get to a 20% or 30% decrease.
What we urgently need right now is to build a solid foundation for the emerging CDR industry. None of the solutions available today are a silver bullet - we will need a combination of them in order to succeed. And we need to invest in early stage CDR solutions TODAY so that they can scale massively tomorrow.
So, what is Carbon Dioxide Removal (CDR)?
So what do we mean specifically when we say CDR (Carbon Dioxide Removal)? CDR can actually be any process that moves a CO₂ molecule from the atmosphere and puts it somewhere where it doesn’t cause problems. There are lots of these processes, and we spell out a handful of them here.
Generally speaking, CDR processes tend to fall under 3 categories:
These include Reforestation and Afforestation, Soil Carbon Sequestration, Kelp Forest Restoration, and more. Usually everyone loves these methods because they come with a host of co-benefits, such as improved ecosystems and biodiversity, and healthier food production. Mangrove restoration can help prevent flooding, for example, and who doesn’t love that?
Technological methods are those that humans invented to either pull CO₂ out of the atmosphere or ocean, or to convert it to other materials. Direct Air Capture (DAC) uses a variety of techniques to collect CO₂ straight from the air and concentrate it, so it can either be used somewhere else or stored someplace safe in combination with another method, such as Mineralization.
Just as the word ‘Hybrid’ implies, these methods use a bit of technology in combination with natural methods to collect and store the CO₂. Some of these include things like biochar, which is half natural (plants sequester carbon as they grow) and half engineered (people pyrolize the biomass to make the biochar). In carbon mineralization, people can use machines to help a natural process along by, for example, grinding rocks to increase overall the surface area for CO₂ to react with.
Which Solution should we use?
It is important to understand that none of these methods by themselves are anywhere near capable of reducing CO₂ concentrations at the level we need, and it is absolutely imperative that we pursue all types of solutions in order to get to gigaton scale CO₂ removal. For reference, humans emit about 50 gigatons of CO₂ per year - that’s 50 billion tons. And no, we are not anywhere close to removing even a significant fraction of that yet - we only have about 10 years to change that, and we can start now by using all methods in tandem, testing for greatest impact, and scaling the most impactful solutions.
Improving the capacity of soil to store carbon
Creating injectable plant-based oil from biomass byproduct
Mineralizing captured CO₂ by injecting it into concrete mixture
Improving the capacity of soil to store carbon
Enhancing natural mineralization processes to permanently store carbon
Replanting forest ecosystems
that sequester CO₂
...and more as they become available.
We need to invest in early stage CDR solutions TODAY so that they can scale massively tomorrow.
Shop by Solution:
So what are we missing? While this all is great, not all of it is a direct solution to the excess atmospheric CO₂ problem. One of the primary things we need to think about when talking about these different carbon sequestration techniques is how permanent the storage is, because it wouldn’t really help to have the CO₂ return right back to the atmosphere.
How Permanent are these Solutions?
One of the primary things we need to think about when talking about these different carbon sequestration techniques is how permanent the storage is, because it wouldn’t really help to have the CO₂ return right back to the atmosphere.
We love Soils as a solution because of the other benefits they provide - they are low cost, understandable and are available now. But Soils might only store carbon for maybe 10 years or so, and there are lots of reasons they might stop storing carbon sooner, for example if someone decided to turn the land into a parking lot. Forests are similar - lots of reasons to plant them, but if we are lucky, trees can only store carbon for decades, likely not centuries and definitely not millenia. They are susceptible to wildfires, disease and destruction by humans.
Biochar is a much more permanent way to store biomass, and may last on the order of 1000 years. Mineralisation and Bio-oil are some of the most permanent ways to store carbon, but these methods are more costly, and we need much more deployment to get the costs to come down.
Permanence is one of the primary considerations when considering the quality of the removal aspect of a CDR project. For now, until we get more techniques to scale and get costs to come down, the more permanent options are usually the most expensive (though you only have to do them once!) Of course, the climate crisis is not the only crisis humanity is facing, so co-benefits, such as biodiversity support or increased food supply, should not be overlooked. And then there are other things to consider as well, such as how additional each project is, will the project cause damage to happen somewhere else, and can it be effectively monitored after to make sure the CO₂ is safely stored and ecological impacts are kept to a minimum.
What if we don't?
Most climate action is focused on decarbonization - things like replacing fossil fuels with solar and wind energy. These things absolutely need to happen, and fast, but we are too late in responding to the climate crisis to expect the problem will magically disappear after we reduce emissions. Even if we stopped all CO₂ and other greenhouse gas emissions yesterday, we already have too much extra CO₂ in the atmosphere right now, and this CO₂ will not draw itself down for thousands of years. We humans made this mess, and it’s up to us toactively clean it up. That is what CDR is all about - without it, we are just accepting that we are willing to live with the mess that has already been made, despite the consequences to our health, our ecosystems and our society.