Abstract

Many modeling studies depend on direct air capture (DAC) in their 1.5°C stabilization scenarios. These studies rely on assumptions that are overly optimistic regarding the cost and scaling-up of DAC systems. This can lead to highly misleading results that can ultimately impact the ability to reach climate stabilization goals.

  • Thorry84@feddit.nl
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    26 days ago

    Remember kids, it takes as least as much energy to put the carbon back as we got out of it when we released it. And because this is the real world and not some math on paper it takes somewhere between 8 and 12 times as much energy to put it back as we got out of it.

    People think gas is expensive now, it should have been at least 10 times more expensive if we wanted it to be carbon neutral. Think about all the power we used by releasing carbon in just one year, we would need 10 years just to put it all back. Gasoline has powered the modern world, but it turned out to be a curse instead.

  • naeap
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    26 days ago

    I Just don’t see the technical possibility and only see DAC as a red herring

    Everything we do costs energy and nothing is 100% effective
    Using ineffective ways to gather and refine oil, moving out around the world to end users, which is it in ineffective ways. And then we need energy to power carbon capture technologies that are also not 100% effective.

    We’re basically have an energy problem and as long as we don’t solve that, we’re fucked.
    Yeah, yeah, using green energy to capture carbon is an option. Why don’t use the green energy in the first place to get rid of the standing supply chain of oil, powering highly ineffective applications?

  • Duamerthrax@lemmy.world
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    26 days ago

    Plant trees. Plant a lot of trees. With current tech, dollar for dollar, it’s the most effective method. Spend on researching industrial methods, but don’t get taken for a ride by a VC firm over promising.

    • Thorry84@feddit.nl
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      26 days ago

      The issue with trees is they are part of the short-term carbon cycle. Humans are stealing power from the long-term carbon cycle. Once carbon gets released from the long-term cycle, it takes millions of years to put it back. Putting carbon from the long-term cycle into the short-term cycle kinda works, but it doesn’t really help. All of that carbon gets released back in a couple of decades to maybe a hundred years.

      There are many many other issues with planting trees, but the only real solution is to stop stealing power from the long-term carbon cycle.

      • Duamerthrax@lemmy.world
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        26 days ago

        You’re supposed to landfill the trees after they’ve reached maturity. Pick a species that makes wood mass quickly, cut once it maxizes, cut and dump in a land fill and repeat. This of course after we’ve stopped putting old carbon into the atmosphere.

        • Thorry84@feddit.nl
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          26 days ago

          How would you ever contain the co2 gas? It will simply diffuse out. People have enough issues with containing radioactive waste, and that’s a solid encased in layers of steel and concrete made to be watertight and stored in deep storage. Containing a gas in soil for a longer while is impossible I would think.

          Simply putting it into a landfill will cause it to decompose and release the carbon in the form of carbon dioxide and methane.

          This is actually a big problem in permafrost regions. As the region became permafrost, the plants died and got compacted. Because of the cold, not all of it could decompose. Now as the climate heats up, these cold regions once again become warm and the decomposition resumes. There’s places where pockets of methane gas collect, you can punch a hole on the ground and light it on fire. The methane normally releases on its own without humans around to burn it off. Since methane is so much more powerful of a greenhouse gas, this contributes to climate change substantially. That’s why in places where methane gets released it’s usually demanded by law to burn it, because that way it’s only co2. Co2 is still bad, but better than methane.

    • Rhaedas@fedia.io
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      26 days ago

      Plant trees to recover diversity. It’s not a solution for carbon capture. Not that it won’t capture a lot of carbon, it will…but what’s now in the air is the product of millions of years of plant capture all released in a century. A completely forested Earth is only a percentage of that, and we can’t and won’t cover that much area anyway. So planting trees is always a great idea, just not to fix this particular problem.

      Neither is DAC, but for different reasons. Mainly power use and entropy.

    • AA5B@lemmy.world
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      26 days ago

      All too often trees are a way to cheat, greenwashing when you don’t actually care about making change. It’s not that planting trees aren’t effective and cost efficient, but that it’s easy to play fast and loose with whether you actually made a difference