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grundar t1_irs1w9b wrote

> by 2050 we’ll need to remove and store 5-16 billion tons per year.

This is the key point.

Direct air capture of CO2 is far too small-scale to be an excuse to slow down emissions reduction; that's not even on the table.

What DAC is useful for is:

  • (1) Offsetting hard-to-decarbonize edge cases.
  • (2) Reducing atmospheric CO2 to minimize overshoot.

To accomplish either of those goals, though, DAC will need to be deployed at a massive scale mid-century, and research shows it takes decades to scale up to that level of operations. Scaling up a large industry by 10x takes ~15 years, and there's less than two of those before 2050.

So the point of working on DAC now is not to have an excuse to delay emissions reductions; nobody serious is proposing that.
The point of working on DAC now is so it will be available at the scale needed in mid-century.

Mitigation at this scale takes decades of preparation.

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