The Essentials of Carbon Dioxide Removal Technologies
To tackle climate change, we have to stop burning fossil fuels that emit ever more greenhouse gasses. We also need to deal with some of the carbon dioxide (CO2) we’ve already released into the atmosphere.Imagine your bathtub is running and overflowing. We definitely need to turn off the faucet, but we also need to clean up what's spilled over. That's where Carbon Dioxide Removal (CDR) comes in, acting as a crucial mop-up operation for our planet's atmosphere.
Two Roads: Removal vs. Capture
There are a few common processes that are often bunched under the term carbon removal: removal from the air through Direct Air Capture (DAC) or Nature-Based Solutions (NBS) and Carbon Capture, Utilization, and Storage (CCUS).
DAC and NBS focus on taking CO2 directly from the air, where it's been causing climate change, and storing it safely away where it can't do any harm. In contrast, CCUS catches CO2 right where it’s produced (like a coal power plant or steel factory) and either re-uses it for fuel or compresses the CO2 and stores it underground. While the idea of CCUS sounds attractive, so far CCUS’s track record has been spotty and there is a reason it’s been a long-time favorite of oil and gas companies. In reality, there are only about 40 sites with functional CCUS in the world: most of them are using the captured carbon to help pump out more oil and the rest have been billion-dollar failures. There are promising storage uses, such as turning the CO2 into a solid mineral or putting it in concrete, but these are methods more commonly attributed to Direct Air Capture projects.
Direct Air Capture: A Glimpse into the Future
One of the most talked-about methods of CDR is Direct Air Capture (DAC). Picture a giant vacuum cleaner for the air, sucking in CO2 and storing it safely. This technology is still growing but may hold the promise of directly tackling the dispersed CO2 in our atmosphere. The problem is that DAC projects are power hogs. They need lots of energy to work. If they don’t run on renewables, we end up with even more CO2 in the atmosphere than we’re sucking out. Companies such as Climeworks and Heirloom currently offer the most promising forms of DAC.
Nature-based and Hybrid Solutions
While technology offers one path, nature itself is a powerful ally. Trees, wetlands, and seas naturally absorb CO2. Innovative hybrid solutions such as Bioenergy with Carbon Capture and Storage (BECCS) and Enhanced Rock Weathering are emerging to try to marry technology with natural processes. BECCS, uses plants or biomass (organic material that can grow back) to soak up CO2, then captures the CO2 released when that biomass is converted into energy. This method not only removes CO2 from the atmosphere but also produces energy, making it a double win. The current scientific consensus is that there are meaningful local, small-scale applications for BECCS, but that it has real limitations to scale.
Enhanced Rock Weathering is the process of spreading finely ground rock on land to react with CO2 in the air, turning it into stable minerals. It mimics natural geological processes but speeds them up, offering a way to lock away carbon for thousands of years.
Why It Matters
Dealing with carbon dioxide removal is a complex issue and each solution has its pros and cons. We need effective CDR technologies that are scalable, sustainable, and affordable. Innovations in this space are moving fast, and support from both the public and private sectors could help accelerate this progress.
It's crucial to remember that promising technologies like DAC are part of a larger puzzle. They're not a silver bullet but a supplement to essential efforts to reduce emissions, transition to renewable energy, and protect and restore nature. By combining both reducing emissions and removing CO2, we stand a better chance of avoiding the worst impacts of climate change.
Get Involved
Curious about how you can contribute to the fight against climate change or learn more about these technologies? Exploring Terra.do’s educational resources and staying informed about the latest developments in climate solutions are great first steps.
-written by Isaac Shamam