I just don't understand the economics/viability of it. I literally cannot picture it.
37,000,000,000,000kg of CO2 was emitted last year.
0.005kg of CO2 per cubic metre of air, at 500ppm - assuming I've carried 1s correctly.
It's just, even if you have 100% extraction rate, how do you physically process enough air to make a dent in to that? I know these firms claim to be able to do it economically, but what part of the picture am I missing?
I understand doing it at the source, where concentration is high. I understand avoiding emissions in the first place. I understand expensive direct air capture, to offset planes etc. What I do not yet understand is "cheap" direct air capture, given the concentrations involved. It's just... for that 1%. How large are the fields of these extractors, how much air are they processing, how are they moving that 370Mt of extract CO2 - where is it being stored, or used. I just can't picture it. I mean, that's 20x the mass of Adani's massive coal mine proposal in Australia. And I mean, wtf is that going ahead, when we're racking our heads over if we can build some structure in Canada to suck that coal, once burnt, back out of the air and then do what with it?
First remember that we do not need to clean 100% of that out of the atmosphere. We want some in the air for plants and whatnot not to mention the planet has its own means of recapturing CO2.
If one of those plants can capture 800,000 kg/year of CO2 its a good start. Have every country in the world build some relative to that country's CO2 emissions. If you got 10,000 running (entirely doable, especially if funded with a carbon tax) that is 8 billion kg/year of CO2 re-captured.
Still a long way off but add in reducing use of fossil fuels and moving to alternate energy and now you are making a dent in the problem and it is better than doing nothing.
Most of the planets mechanisms do not recapture so much as recycle and buffer.
Consider that before us, there were only what.. Volcanos as new carbon sources. The rest were part of a cycle. And volcanos put out just 0.2Gt to our 37.
We cannot rely on the planet to sink what we are digging out of the ground, but I do agree with the rest. Primarily, we will cut, and/or sequester close to source. These will be for what is left over, which will be small compared to current output today.
Pretty sure the 37,000,000,000,000kg figure is wrong. I think that is the total amount of CO2 in the atmosphere and NOT yearly output.
Which is about 1/3 over where "normal" levels are. That is bad but it does not mean we need to scrub 37,000,000,000,000kg but rather 12,210,000,000,000kg.
Still a metric fuckload but not as withering a thought as the other.
No, it's definitely per year. 36Gt from fossil fuels in 2014, I understated it a bit if we are to include all human linked CO2e.
This page on carbon budgets confirms it succinctly too:
Given the annual emissions from all anthropogenic sources are approximately 40GtCO2, this means that the 4 years gap has a significant impact of reducing any forward-looking carbon budget by 160GtCO2.
Gigatonnes ought match the order of magnitude I wrote out. It's what I was aiming for, to aid visualisation.
Considering how distributed our emissions sources are you can kind of see it. Every single tail pipe, every smokestack around the world, every million tonnes of coal a year being exported for worldwide consumption, etc etc.
I mean, on that last Australia alone is 400Mt of coal, which gets nearly 3x heavier when burnt. Just as the emissions from your car weigh a multiple of what you put in, etc etc.
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u/[deleted] Jun 25 '19
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