this post was submitted on 09 Jul 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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[–] 14th_cylon@lemm.ee 20 points 4 months ago (2 children)

we can't.

air conditioning does not work with hundred percent efficiency, so you will cool your apartment, removing x joules of heat from inside and create 1,1 x joules of heat outside. your apartment is now temporarily colder, but there is more heat in total than there was before.

you will now be tempted to use the air conditioning even more, creating even more heat. welcome to hell.

[–] ptz@dubvee.org 9 points 4 months ago (1 children)

Yep. That's also not counting the heat generated from the electric transmission infrastructure between the power plant and your dwelling. Plus the extra emissions from dirty power plants to power all of the A/C.

Hell indeed.

[–] 14th_cylon@lemm.ee 4 points 4 months ago* (last edited 4 months ago) (2 children)

Plus the extra emissions from dirty power plants to power all of the A/C

i mean if we had AC that would work with 100% efficiency, then it would be the prime use case for solar panels. you only need AC when there is a lot of sunlight and vice versa.

[–] HobbitFoot@thelemmy.club 2 points 4 months ago (1 children)

Technically, all heat pumps have greater than 100% efficiency. It is how electric heat pump heating can compete with natural gas heating in terms of efficiency.

[–] brisk@aussie.zone 1 points 4 months ago

They have a greater than 100% Coefficient of Performance, which is often marketed as efficiency in heat pumps. Their efficiency is bounded between 0 and 1 like every other physical system.

[–] ptz@dubvee.org 1 points 4 months ago (2 children)

I don't think we'll ever make any machine that's 100% efficient (electric resistance space heaters aside), but maximizing the efficiencies we can will at least mitigate most of the problems if they're powered by clean energy.

Not sure if ground source heat pumps (which would heat the ground rather than the air in the summer in AC mode) would make a meaningful difference or not.

[–] mojofrododojo@lemmy.world 3 points 4 months ago

Not sure if ground source heat pumps (which would heat the ground rather than the air in the summer in AC mode) would make a meaningful difference or not.

I worry that this will just displace the problem for a generation, and eventually, just as the atlantic ocean has warmed to fucking jacuzzi levels, eventually we won't be able to pour more heat into the ground.

https://apnews.com/article/record-hot-water-florida-coral-climate-change-6414d44c6f120507d3ee37c059fb75cd

[–] 14th_cylon@lemm.ee 2 points 4 months ago (1 children)

I don’t think we’ll ever make any machine that’s 100% efficient

i didn't mean to imply that, it was purely theoretical remark

[–] ptz@dubvee.org 2 points 4 months ago

Yea, I got that :) just building on it.

[–] mojofrododojo@lemmy.world 4 points 4 months ago

we can’t.

but the rich will. they won't hesitate even if they know it's making things worse for everyone.

watch.

[–] toaster@slrpnk.net 13 points 4 months ago

This was a great, succinct article. Here are a few key points that I noticed:

The important result here is that the efficiency of your air conditioner decreases as ∆T increases — e.g., as the outside temperature goes up.

the work required to keep your house at a fixed temperature Tc increases with the square of the temperature difference between inside and outside temperature, ΔT².

Let’s use the same numbers from the previous example: you want to keep your house at 75F. If climate change has increased the outside temperature from 96F to 100F, the energy your air conditioner consumes increases by (100-75)2/(96-75)2 = 252/212 — this is an increase in energy consumption of 42%!

Averaged over an entire day, the increase will be less than this because ∆T is smaller for much of the day (e.g., at night) But the result is robust: climate change is driving exponentially increasing energy demand for cooling.

People with financial means, who work in air-conditioned offices and live in climate-controlled homes, can handle rising temperatures by simply paying for more electricity.

However, a significant portion of the global population lives the hot life. These people live in homes without air conditioning, work outdoors or in warehouses or kitchens with no climate control.

[–] Tronn4@lemmy.world 1 points 4 months ago (1 children)

Why don't we build a tunnel to space? Heat goes up so it'll go out to space where it's cold and some cold air would come in. Win win

[–] millie@slrpnk.net 4 points 4 months ago* (last edited 4 months ago) (1 children)

Heat doesn't go up. Hot air rises because it's less dense than cold air. You know what's less dense than hot air though? Vacuum. That's a good thing, though, because we don't want to be hemorrhaging atmosphere.

Even if we could build a physical heat sink sticking out of the atmosphere somehow, it would be less protected from solar radiation than anything inside the atmosphere, so if it were facing the sun it probably wouldn't work.

Even if we had the resources and like, enough readily available materials on Earth to make some sort of retractable heat sink sticking out of the night-side of the planet, it'd probably require more energy consumption to create than would be worth it.

Probably the best way to cool things down is to quit burning so much shit and quit knocking forests down.

[–] Tronn4@lemmy.world -2 points 4 months ago

Are you assuming heats gender? /s