Humanity is releasing tens of billions of tons of carbon dioxide into the atmosphere every year. Given the rather limited attempts at mitigating this, the climate crisis is getting more and more serious with every passing day.
One of the many approaches being investigated is a method to suck carbon dioxide directly out of the atmosphere. A study published in Nature Communications has now tried to estimate its potential impact, with some good news as well as some less than good news.
The team assessed two direct air carbon capture and storage (DACCS) technologies that are currently in development, specifically focusing on their possible scalability and energy consumption. They estimated that once fully deployed, the two DACCS approaches could remove on average 1.5 billion tons of carbon dioxide per year. This would make a significant dent, but such technology is not a magic bullet and doesn't come without its costs.
The two DACCS methods use sorbents, substances that can trap certain molecules. One of the methods uses water-based sorbents, while the other uses sorbents derived from ammonia. For large-scale capture, there would need to be considerable production of these sorbent materials to trap CO2. The technologies are not passive, as air needs to be pump through them, which means the tech could require between 10 to 15 percent of the energy production of 2100 in order to work at maximum efficiency, according to the team's estimates.
The deployment of this technology could reduce the cost of cutting emissions over the next few decades since emissions wouldn't have to fall as steeply. Yet, the researchers warn that this is a gamble that might not pay off, with some serious consequences if it doesn't.
“Our analysis shows that in theory DACCS can be an enabling factor for the Paris Agreement objectives: it allows their achievement at lower costs, by more-than-halving carbon prices in 2030,” wrote the researchers in the paper.
“The analysis also highlights the clear risks of planning a long-term mitigation strategy on the assumption that DACCS will be available and can scale up at speed.”
If the technology doesn’t develop as expected, the emissions will still be there and lead to an overshoot of around 0.8°C of the Paris Agreement target. The team concludes there should be an investment in carbon-capture technological developments but not at the expense of other methods and without easing up on the near-term mitigation approaches.
There’s also been recent estimations on large-scale reforestation efforts, which suggest they could be extremely useful in removing carbon dioxide from the atmosphere.
[H/T: Carbon Brief]