This oppressive summer of 2023 provides stark confirmation that the climate crisis is not some far off looming threat but instead an alarming reality we’re already grappling with. The ocean in Florida in July is nearly as hot as a jacuzzi – ten degrees above normal, and worldwide heatwaves show no sign of easing in the weeks ahead. The hottest temperatures usually occur late in the year around August, but this year the global record was broached in early July, a significant outlier.
Conservative leaders have long been complacent, stalling and kicking the can down the road hoping for some singular, miraculous solution like geoengineering to emerge and solve everything. So it is encouraging that climate policy has finally been addressed in the form of the Inflation Reduction Act, an almost shotgun approach to incentivize research and private investment in lots of various climate solutions with grants and tax credits.
Stop Digging
The first step is to stop digging the hole deeper. Energy production and the internal combustion engine (ICE) are the two biggest drivers of emissions, and fortunately, progress in renewable energy production and electrifying transportation is promising. But it will be a while – likely more than 10 years, until those sectors see significant transitions to renewables.
The Carbon Capture Landscape
Carbon capture has therefore emerged as an indispensable tool in our arsenal to draw down atmospheric concentrations. A trillion tons of CO2 have been released into the atmosphere over the past two centuries, and 90% of this excess has been absorbed by the oceans, resulting in acidification that is killing base food chain organisms and coral reefs, the ocean’s nursery. Mitigating the catastrophic effects of this carbon footprint requires reducing legacy emissions on top of net-zero energy and transportation goals.
Three carbon capture strategies:
- Carbon Capture and Storage (CCS) captures and stores emissions from energy generation and oil drilling.
- Carbon Capture, Utilization, and Storage (CCUS) captures carbon and also repurposes it.
- Direct Air Capture (DAC) filters ambient air, extracting CO2 for sequestration or use.
CCS and CCUS can be viewed as necessary short-term remedies to the polluting energy generation systems we currently employ. Both will phase out as petroleum is phased out of energy production, but are essential technologies now to not make the problem worse. DAC, in contrast, acts as an environmental filter, scrubbing CO2 from the atmosphere, an approach vital to reduce CO2 concentrations that were 280 ppm before the industrial age, and is now 419.
The scale of the task is sobering. To reach modest climate goals – and in addition to achieving net zero energy production and transportation, researchers suggest we need to construct dozens of DAC plants each year for the next thirty years.
The Challenges of Stored CO2
While carbon capture technology is showing great promise, it is still in its infancy and numerous challenges remain. The most critical issue is what to do with the captured CO2. Currently, the majority is used in the oil industry, where it’s injected into wells to enhance oil and gas extraction – a practice that clearly aggravates the problem instead of solving it.
Commercial use of captured CO2 is currently limited. But beyond compressing and pumping CO2 underground, carbon mineralization offers a promising alternative. This process transforms CO2 into calcium carbonate, either by injecting it into specific underground formations or by reacting it with mined minerals to solidify.
A Beginning
There are now a number of DAC plants and projects worldwide that are helping drive progress and innovation. One such plant in Iceland, named Orca and begun by Climeworks in 2021, removes 4,000 tons of CO2 annually and has been approached as a research project to learn easy replication and future scaling. It is powered by geothermal energy and is nearly a thousand times more effective than trees in terms of land use efficiency to remove CO2, which in partnership with Carbfix mixes CO2 with water and injects it underground where it crystallizes, resulting in permanent storage. Climeworks claims there is a nearly inexhaustible supply of these formations worldwide, more than enough for the storage required to bring concentrations back to pre-industrial levels.
Another company, Carbon Engineering of British Columbia, is now building two plants – in Arizona and Scotland, that will also be powered by renewable energy and are each planned to remove a million tons annually.
Calcium Carbonate
A promising approach is to create commercial products with the CO2 above-ground by mining reactive agents such as basalt and mixing it with CO2 to create calcium carbonate. It’s an energy-intensive process that is sustainable only if using renewable energy, but progress happens faster when there’s a monetized reason to do so. And calcium carbonate has uses such as additives in cement and paint, in agriculture, health supplements, and is a main ingredient in antacid.
Scientific advances always begin with widespread skepticism, clunky first designs, and exploding rockets. Eventually though, the setbacks give way to refinement, progress, and success if eager smart people are given the policies and resources to do it.