this post was submitted on 18 Jun 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] 7 points 6 months ago (1 children)

https://phys.org/news/2024-06-satellite-megaconstellations-jeopardize-recovery-ozone.html

When old satellites fall into Earth's atmosphere and burn up, they leave behind tiny particles of aluminum oxide, which eat away at Earth's protective ozone layer. A new study finds that these oxides have increased 8-fold between 2016 and 2022 and will continue to accumulate as the number of low-Earth-orbit satellites skyrockets.

Those micrometeors aren't mostly aluminium.

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

Those micrometeors aren’t mostly aluminium.

Do you have a source for that? Perhaps I'm misunderstanding you, but I've found a number of sources that show that meteorites contain aluminum:

To be fair, I don't think any of those claim that any meteorites are "mostly" aluminum. But is that a true requirement?

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

I did write "mostly" for a reason. Aluminium is used a lot in aerospace due to its low mass. There is a lot of matter falling from space naturally, but the composition is key to the effects that will have on the atmosphere. Satellites, spent stages etc. have different compositions to meteors.

Over 20 elements from reentry were detected and were present in ratios consistent with alloys used in spacecraft. The mass of lithium, aluminum, copper, and lead from the reentry of spacecraft was found to exceed the cosmic dust influx of those metals. About 10% of stratospheric sulfuric acid particles larger than 120 nm in diameter contain aluminum and other elements from spacecraft reentry. Planned increases in the number of low earth orbit satellites within the next few decades could cause up to half of stratospheric sulfuric acid particles to contain metals from reentry.