Can negative emissions technology clear the air without costing the Earth?

The numbers are mind-boggling. To prevent catastrophic climate change we may need to install 1500 direct air capture plants every year between 2030 and 2050, with each capable of removing 1 million tonnes of carbon dioxide from the atmosphere. This would be a consequence of not having made the deep emissions cuts climate scientists say are imperative.

We also have to capture emissions from plants in hard-to-abate sectors such as steel and cement. The numbers here are perhaps easier to comprehend. The International Energy Agency (IEA) estimates over 1 billion tonnes must be captured every year by 2030 – requiring a considerable scale up from the 40 million tonnes capacity today. Meeting that target would put a dent in the emissions from 5200 industrial facilities globally that the IEA says are each emitting more than 1 million tonnes of carbon dioxide every year.

How much energy is going to be required, however? The answer is clear: it depends. There are such a broad range of sources of carbon dioxide from diverse industries and types of power plant, that different technologies might be needed for different applications. And in every case a scale-up of supply chains for sorbent materials will be required.