Carbon dioxide removal (CDR) technology that leverages natural processes is finally taking off after decades of underfunded development, implementation setbacks and deep skepticism.
Now, the science in the latest IPCC report makes clear that humanity must remove legacy emissions from the atmosphere at a scale of 10 Gigaton per year by 2050. In 2022, the Inflation Reduction Act authorized some $370 billion in spending on climate technologies, including CDR. At the same time, more than 25% of all venture capital investment went into climate tech last year.
Now, with more money flowing in and a market for removal credits, the climate tech industry has the resources it needs to develop solutions that remove carbon dioxide from the atmosphere using a combination of technology and the earth’s natural processes to remove as much atmospheric carbon as possible, as fast as possible. These areas are the keys to finally deploying the full range of decarbonization solutions we urgently need, and they all rely to some degree on rapid innovation in hardware.
Designing CDR technologies for scalability may be the biggest and most urgent challenge of all. A huge amount of innovation and investment is required to build and scale up solutions that will help humanity reach its climate goals over the next few decades. While direct air capture (DAC) projects that filter small amounts of CO2 from large amounts of air are promising in their technology readiness level, these projects alone cannot address the globe’s carbon removal needs. The need for complementary technologies that use less energy and can scale is why many climate technologists and researchers are looking for ways to harness natural processes for CDR.
Hardware development challenges for nature-based CDR
While the recent wave of funding is fueling progress, engineers face other challenges in harnessing nature for large-scale carbon removal, and many of these challenges arise from the interconnected nature of our ecosystems.
The first hardware challenge is to develop CDR solutions that are durable, meaning they sequester captured carbon in a way that won’t leak back into the atmosphere over the next few thousand years. The best way to do this is to remove CO2 from the “fast carbon cycle,” which includes the biosphere, atmosphere, and upper ocean reservoirs and transport it to the “slow carbon cycle,” or the deep ocean reservoirs and inorganic material like rocks, where it can remain for millions of years.
One example of this is turning high-carbon agricultural waste like corn husks into bio oil, which can then be injected into specific geological layers under the earth’s surface, where it will remain indefinitely. This approach to permanent sequestration requires meeting a number of hardware challenges, including processing and pyrolyzing the biomass, separating and transporting the bio-oil to the injection location, injecting it underground, and measuring and verifying the entire process.
Another major consideration for climate hardware development is the need for solutions that require minimal energy input–to avoid creating emissions while reducing them–and are inexpensive to implement and scale. Like the bio-oil example, many of the most innovative technologies in development now meet these requirements by harnessing the natural carbon removal processes of photosynthesis. Another example is that there are several initiatives focused on growing kelp in the ocean to pull in CO2 and then sink it to the sea floor along with its embodied carbon.
It is also critical that any CO2 removal approach be monitored, reported on, and verified, a process referred to as MRV. To perform MRV at scale on a solution like kelp bed storage, it requires hardware for sensors, automation, and connectivity that is designed for a remote ocean environment. Another promising ocean-based solution is Ocean Alkalinity Enhancement (OAE), which enhances the ocean’s ability to absorb atmospheric CO2. OAE faces similar MRV challenges.
Finally, it’s critical to consider the second order impacts of any new CDR approach. Researchers and engineers must carefully evaluate the potential for unintended consequences that could undermine the solution’s effectiveness or cause new problems that may or may not be solvable with technology. Yet some of the most promising solutions can have positive side effects, like enhanced rock weathering (ERW) in which CO2-absorbing minerals are spread over farmland, which also enhances crop yields.
Working with, rather than against, natural processes for a better future
While the emerging wave of hardware innovations for CDR is exciting, it’s critical to evaluate each new nature-based technology on the metrics of durability, measurability, cost, and scalability–in addition to carefully considering the possible second-order effects. This evaluation process will be the key to identifying and developing the best options for CDR so that we, as engineers, scientists, technologists, and society as a whole, know where to focus our resources during this critical window for atmospheric carbon removal.
Dylan Garrett is the Head of Climate Tech Business at Synapse, part of Capgemini Invent. He is also the host of the podcast Hardware to Save a Planet. Dylan works with companies that are leveraging hardware technology to fight climate change with solutions that range from carbon dioxide removal, water conservation, waste management, energy storage and production, and beyond.