Carbon-Sucking Tech To Use More Energy Than All Homes

Technology that sucks carbon emissions out of the air would need more energy than used to run the world’s homes if it’s to play a significant role in reaching global climate goals.

That’s according to a future energy scenario modeled by oil supermajor Shell Plc that includes direct air capture, which filters the gas out of the air so that it can be stored safely and permanently. It’s one of the two main ways to trap CO2 — along with capturing it before it leaves a smoke stack.

Despite net-zero emissions goals in most of the world, governments will need to make big changes to limit global warming well below 2C and avoid the worst impacts of climate change. Getting there won’t just mean sharply cutting back on fossil fuels in favor of renewables and batteries, but also scaling up technologies that sequester CO2.

Direct air capture is still in its infancy and while it could one day be a crucial climate tool, it’s hugely energy intensive. It’s effectively like running a giant air conditioner to cool the atmosphere.

In a scenario in which the world limits global warming in line with the Paris climate agreement, final energy demand for direct air capture rises from about nothing today to almost 66 exajoules in 2100. That would be more than the energy needed to heat and power all the world’s homes by then, according to a report by Shell.

That amount of energy would allow the world’s carbon-sucking machines to absorb more than 5 billion tons of CO2 per year, Shell said. Were that to happen, it would be possible for global warming to be around 1.24C by 2100, after briefly rising above 1.5C in the middle of the century.

Despite the technology remaining fledgling, there’s major interest in it. US President Joe Biden’s climate bill provides significant subsidies to help expand the industry. US oil giant Occidental Petroleum Corp. has already started building what will be the world’s largest carbon-removal plant. 

How the machines fare depends on investment and how the technology develops. But if they do scale up, they’ll need a lot more wind turbines and solar farms to provide low-carbon power.