this post was submitted on 11 May 2024
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Climate - truthful information about climate, related activism and politics.

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Discussion of climate, how it is changing, activism around that, the politics, and the energy systems change we need in order to stabilize things.

As a starting point, the burning of fossil fuels, and to a lesser extent deforestation and release of methane are responsible for the warming in recent decades: Graph of temperature as observed with significant warming, and simulated without added greenhouse gases and other anthropogentic changes, which shows no significant warming

How much each change to the atmosphere has warmed the world: IPCC AR6 Figure 2 - Thee bar charts: first chart: how much each gas has warmed the world.  About 1C of total warming.  Second chart:  about 1.5C of total warming from well-mixed greenhouse gases, offset by 0.4C of cooling from aerosols and negligible influence from changes to solar output, volcanoes, and internal variability.  Third chart: about 1.25C of warming from CO2, 0.5C from methane, and a bunch more in small quantities from other gases.  About 0.5C of cooling with large error bars from SO2.

Recommended actions to cut greenhouse gas emissions in the near future:

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[–] [email protected] 18 points 6 months ago* (last edited 6 months ago) (6 children)

Has anyone done the math and figured out if these things are more efficient than trees? I have my doubts but I'm also a pleb so idk how to compare them.

[–] [email protected] 25 points 6 months ago* (last edited 6 months ago) (1 children)

I haven’t done the math but I studied a lot energy stuff for my degree. I can say for sure that’s it’s a hell of a lot more money and work than just reducing emissions in the first place. The below comment is accurate, if cynical; I knew someone who works on it in the states. You collect a bunch of co2 (using energy), then compress it (with energy), then ship it (yep diesel trucks), to salt caves where it is pumped (with energy) into the empty salt lined cave where the pressure causes the salt to sort of seal in a partial melt from the pressure. And hope we don’t accidentally frack it all back out. Needless to say I think it’s a waste of technology, money, and political will that’d be better spent on a plethora of other options.

[–] [email protected] 9 points 6 months ago (1 children)

Here in Iceland, where this is located, we produce more green energy than we consume and can't store that energy, and the carbon is pumped straight into the basalt below which absorbs it. I think doing it here is a decent way to do research on improving the technology.

[–] [email protected] 3 points 6 months ago

Yea it’s a good tool in places that have unlimited energy sources nearby, like geothermal or hydroelectric

[–] [email protected] 13 points 6 months ago* (last edited 6 months ago)

I mean just looking at the amount of concrete in that picture, I get pessimistic. When will this particular site have dug itself out of the carbon "hole" created by its construction?

As for trees: That is really, really hard to measure and even harder to know in advance. Some factors appear to be:

  • different tree species store different amounts of carbon
  • tree plantation or actual forest?
  • prior use of the site (e.g. meadows do store carbon too)
  • development over time (most trees need to grow a couple years before they start storing significant amounts of carbon)
  • failure of sites due to being planted in a bad way (e.g. a lot of Chinese Green Wall sites and quick-buck billion tree projects seem to be affected by this)
[–] [email protected] 11 points 6 months ago

IIRC, a tree absorbs up to 3 tons/year, and takes a bunch of years to get to that stage.

The trees also don't sequester underground, and will need surface area staying as forest for the rest of time.

As many have echoed: an ounce of prevention saves a pound of cure. Most bang for our buck would be to change our lifestyle and regulations. But as that's not feasible we're at the geo engineering and artificial sequestration stage.

[–] [email protected] 6 points 6 months ago (1 children)

I don't know what more efficient means here. The CO2 is stored sorta permanently underground, whereas trees release their CO2 when they rot or burn.

Trees are kind of better because they grow on their own, and don't require massive amounts of green energy to scrub the atmosphere.

[–] [email protected] 1 points 6 months ago

CO2 generally is released in cycles. Wood rots, new forests grow etc. The biggest issue is that we went from slow cycles such as carbon is stored in fossil fuels that VERY slowly release CO2 through natural processes, to extremely rapid release of CO2.

[–] [email protected] 5 points 6 months ago

How do you measure "efficiency" ? By money spent? Then yes, trees are currently cheaper. But trees are complicated (see other comments). Additionally, even if we cover the whole landmass with trees, there is still a catastrophic amount of Co2 left in the atmosphere.

[–] [email protected] 2 points 6 months ago