this post was submitted on 03 Dec 2024
109 points (100.0% liked)

Climate - truthful information about climate, related activism and politics.

5383 readers
108 users here now

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:

Anti-science, inactivism, and unsupported conspiracy theories are not ok here.

founded 2 years ago
MODERATORS
[email protected]
109
Pulling CO2 out of the air won’t stop climate change…unless it is stored for at least 1,000 years. Researchers pinpoint an unexpected threat to climate action: ambiguous carbon accounting (www.anthropocenemagazine.org)
submitted 2 weeks ago by [email protected] to c/[email protected]
16 comments fedilink hide all child comments
you are viewing a single comment's thread
view the rest of the comments
[–] [email protected] 21 points 2 weeks ago (1 children)

The storage part is a big issue with current plans for CCS and DAC. If they end up turning around and repackaging the CO2 into something that can be released again, it's only better than pumping out new petroleum and not a true reduction.

But the title is a bit wrong. It should be "Pulling CO2 out of the air alone won't stop climate change". Even if we dropped the CO2 level to preexisting levels (280ppm or even lower) there are still some feedbacks already in play that wouldn't suddenly stop their contribution. It would be far better than continuing to add to CO2 for sure, but there is still going to be some climate change and adaptation needs regardless of how well we act. And of course, we are not acting very well.

[–] [email protected] 2 points 2 weeks ago

Mineralization. There is a paper from Nature estimating a capacity of 10,000 - 100,000 Gt CO₂ for mineralizing CO₂. This is more than sufficient for the 1,000 - 2,000 Gt CO₂ that we will need to remove from the atmosphere once we reach zero emission. Needless to say, mineralization to a solid carbonate would remove the threat of fugitive emissions permanently.

People can complain about DAC as expensive etc., but it is the fastest way to bring down CO₂ once emissions have ceased. Without it, we will be stuck with the climate effects of increased greenhouse gas emissions - severe storms, erratic climate events - for hundreds of years. The fact that it is expensive just means that we will need to know what our target CO₂ level is and how how fast we want to get there.

Often, it's said, "Just plant trees." However, trees are not a sufficient solution for greenhouse gas reduction. A 2022 article in Environmental Research Letters predicts a "121 Gt C increase in carbon in forests over the course of this century." That's great, but it's not enough to get GHG down to an ideal level. Of course, that doesn't mean that we shouldn't engage in sustainable agriculture and reforestation - we should, but we should not rely on it as a climate restoration strategy because it cannot deliver those kinds of GHG reductions.