Cutting emissions is not enough. Stabilizing the climate also requires removing carbon from the air, the UN recently warned. For now, the technology is very limited and expensive. But some of the world’s biggest companies want to accelerate development.
In April, Stripe, Alphabet, Shopify, Meta and McKinsey committed to spending nearly $1 billion doing just that over the next nine years.
Its early commitment to the market aims to promote innovative technologies, ensuring future demand for them. The money will be spent on direct air capture (DAC) projects, which have the potential to be low-cost — less than $100 per ton — and high volume in the future.
The goal is to store carbon permanently, or at least for over a thousand years. This avoids the risks of natural carbon sequestration projects, such as planting trees, which are vulnerable to fire and decay.
DAC costs are currently at least US$250 (R$1,199) per ton of COtwo removed, says the World Resources Institute. the COtwo represents just 0.04% of the air, so trapping a ton of the gas means processing as much air as would fit in about 525 Olympic-sized swimming pools. This makes it much more expensive than capturing carbon from industrial processes or power plants, where emissions are more concentrated.
Therefore, cheap renewable energy plays an important role in DAC. Swiss start-up Climeworks, which raised $650 million in April, and Icelandic Carbfix are using geothermal energy to power fans at the world’s largest DAC plant in Iceland. Once the air is sucked in, the carbon dioxide is captured in a chemical filter. It is then injected underground, where it is turned into rock by mineralization, a natural process.
The capacity of a plant planned by Occidental Petroleum in the Permian Basin (Texas) will be 250 times greater, capable of removing 1 million tons of COtwo per annum. It will cost up to US$ 1 billion; the goal is to build 70 by 2035, the American company said in March.
Investors are unlikely to value the opportunity yet. There is a lot of uncertainty: overfunding, government support, cost savings, and the size of the voluntary compensation market.
There’s a lot to do before technology comes of age. The proportion of carbon emissions currently being captured was compared to rescuing the Titanic using a dropper. DAC is not an alternative to reducing emissions. But magnified, it could make a crucial contribution.
Translated by Luiz Roberto M. Gonçalves
