But everyone I spoke with, including the most fervent advocates for carbon removal, stressed the huge challenges of the work, some of them technological, others political and economic. Done on a scale significant enough to make a difference, direct air capture of the sort pursued by Carbon Engineering, in British Columbia, would require an enormous infrastructure, as well as huge supplies of power. (Because CO2 is more dilute in the air than it is in the exhaust of a power plant, direct air capture demands even more energy than C.C.S.) The power would have to be generated emissions-free, or the whole enterprise wouldn’t make much sense.
“You might say it’s against my self-interest to say it, but I think that, in the near term, talking about carbon removal is silly,” David Keith, the founder of Carbon Engineering, who teaches energy and public policy at Harvard, told me. “Because it almost certainly is cheaper to cut emissions now than to do large-scale carbon removal.”
beccs doesn’t make big energy demands; instead, it requires vast tracts of arable land. Much of this land would, presumably, have to be diverted from food production, and at a time when the global population—and therefore global food demand—is projected to be growing.
more here.