this post was submitted on 09 Sep 2023
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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] 6 points 1 year ago (1 children)

Every time we had a new energy source, we just added it to the mix. We always had to activly cut the usage of the old one to cause a decline. So renewables just can not grown fast enough to cause a decline in fossil fuels. They however can replace them, if we cut them in a smart way.

[–] [email protected] 2 points 1 year ago (2 children)

That's not really true at all. Significant parts of the world have managed substitutions in recent decades, in particular the decline of coal use in the US and EU looks like replacement, rather than "adding to the mix" on a regional level, and neither part of the world is exporting coal to the places that are burning it.

What we do is a choice, not some inevitability of adding new energy sources to the mix.

[–] [email protected] 1 points 1 year ago (1 children)

The US is a net exporter of coal and since 2007, when gas really started to grow, coal imports have fallen and exports have somewhat increased. The good part is mining it in the US is just too expensive, so mines do close down, but it is not a clear win. https://www.eia.gov/energyexplained/coal/imports-and-exports.php https://ourworldindata.org/grapher/electricity-prod-source-stacked?country=~USA

As for the EU, there is a working emissions trading system, which limits emissions, so there is active cutting of fossil fuels and coal is the easiest to replace.

[–] [email protected] 1 points 1 year ago (1 children)

this seems incredible to me. especially given the co2 emission-equivalency with the deforestation of the amazon. i haven't clicked the link, but do you know whether that calculation takes deforestation into account?

[–] [email protected] 1 points 1 year ago

Yeah, deforestation is a much smaller impact thing at this point than fossil fuels. Big enough to matter, but only a bit of the overall problem.

Per the IPCC:

Based on multiple lines of evidence using interhemispheric gradients of CO2 concentrations, isotopes, and inventory data, it is unequivocal that the growth in CO2 in the atmosphere since 1750 (see Section TS.2.2) is due to the direct emissions from human activities. The combustion of fossil fuels and land-use change for the period 1750–2019 resulted in the release of 700 ± 75 PgC (likely range, 1 PgC = 1015 g of carbon) to the atmosphere, of which about 41% ± 11% remains in the atmosphere today (high confidence). Of the total anthropogenic CO2 emissions, the combustion of fossil fuels was responsible for about 64% ± 15%, growing to an 86% ± 14% contribution over the past 10 years. The remainder resulted from land-use change.

And CO2 is big enough that this means that fossil fuels are the biggest piece of the problem: