Direct Air Capture

In How To Avoid a Climate Disaster, Bill Gates treats direct air capture (DAC) as a distinct decarbonization technology from point capture — and a likely-essential one. Where point capture installs devices at fossil-fuel plants to absorb emissions before they hit the atmosphere (an approach that “existed for decades” but is expensive, captures only ~90%, and gives power companies no upside), DAC does “exactly what the name implies: capturing carbon directly from the air.” Its advantage is flexibility — “you can do it anywhere” — which is why Gates argues it’ll “in all likelihood … be a crucial part of getting to zero.”

Gates anchors the scale of the problem in a National Academy of Sciences study he cites: roughly 10 billion tons of CO₂ removed per year by mid-century, rising to about 20 billion by century’s end. But he flags DAC as “a much bigger technical challenge than point capture, thanks to the low concentration of carbon dioxide in the air” — the core physics problem that makes pulling diffuse CO₂ from ambient air far harder (and costlier) than scrubbing a concentrated smokestack. The book groups both methods under Carbon Capture as parts of the path to zero.

Context: Direct air capture is an industrial carbon-removal technology that chemically scrubs CO₂ from ambient air; companies like Climeworks and Carbon Engineering operate early commercial plants. Because atmospheric CO₂ is only ~0.04%, DAC is energy-intensive and costly per ton — the central economic and engineering hurdle to scaling it as a climate solution.

Where this appears

• How To Avoid a Climate Disaster — Gates distinguishes DAC from point capture, frames it as a likely-crucial but technically harder path to net-zero, and sizes the gigaton-scale removal it must eventually deliver