this post was submitted on 17 Mar 2025
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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.

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Best technology for coal electricity capture costs $10/watt (close to new on budget nuclear plants), and only captures 65% of emissions. A better "free" climate strategy would be to put them in "backup peaker" mode for renewables and run them at far less than 35% of year.

DAC can work only if price of carbon is $300/ton ($3/gallon gasoline). Still, 100% renewables is cheapest path to avoiding those taxes, but afterwards, DAC can hope to pay for itself.

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[–] humanspiral@lemmy.ca -5 points 1 day ago (4 children)

Hydrogen gets a short poo poo in video. It's only path to 100% renewables. Airbus slowing down, has no impact on China solutions, and helping airbus with what it's good at: airframes.

[–] futatorius@lemm.ee 1 points 55 minutes ago

It’s only path to 100% renewables.

That's nonsense. Hydrogen is just another engery storage technology, and an inefficient one.

[–] solo@slrpnk.net 2 points 9 hours ago (1 children)

I am not really familiar with hydrogen energy. I just found this community that I will look into. Do you perhaps have some resources to share?

[–] humanspiral@lemmy.ca 2 points 4 hours ago (1 children)

Electrolysis of Hydrogen is green if renewables power it. It is almost as automatable as battery storage. It is transportable/exportable energy that is cheaper to transport than building electric wires, even by truck. A fuel cell is a hydrogen to electricity converter that is twice as efficient in obtaining power from fuel than an ICE engine. Other than fuel, hydrogen has many critical chemical applications.

Hydrogen electrolysis is the key technology. Just make it, and figure out how to sell it later. Biden's IRA was ok for hydrogen. China is doing better as usual. Truck sized electrolysis systems makes electrolysis portable too, and could be used to chase seasonal surplus renewables. The key to 100% renewable power is having enough power every day, and so on most days have surpluses. Hydrogen is path to monetizing that surplus, in addition to displacing some energy use with backup/resilience exportable energy.

[–] solo@slrpnk.net 2 points 3 hours ago

Thank you very much for this intro!

[–] riodoro1@lemmy.world 0 points 8 hours ago

Oh look, here’s a toyota spokesperson.

[–] adrnvrt@lemm.ee 4 points 20 hours ago (2 children)

I think the main problem with hydrogen in Airplanes is the storage. You need either insane pressure or extremely low temperature. Both is tricky for security... And energy density is low... As far as I know no one has technology wise a real edge over anybody else at the moment. We'll see how it turns out...

[–] Nighed@feddit.uk 0 points 6 hours ago (1 children)

I think the designs all end up as big combined wing aircraft to give more storage. Can work, but so many new techs and challenges that no one is really investing in it....

Airport expansions like at Gatwick and Heathrow in the UK (both very contentious) should have carbon caps to encourage investment in this kind of stuff.

[–] futatorius@lemm.ee 1 points 53 minutes ago

There shouldn't be further expansion at Heathrow in particular, it's already a blight on southwest London as it is.

[–] humanspiral@lemmy.ca -2 points 20 hours ago

For aviation, LH2 is best because the tanks are very light too, and much of the fuel is used on takeoff which has a cooling effect on the remaining fuel. Cruising at matched boil off rate works well, and there should be enough pressure resilience for reserve fuel. Small battery can also help with takeoff and regen to handle aborted landings, as well as manage with boil off rate.

A technical challenge is dealing with very cold/liquid H2 in the fuel cell, and pipes. Unclear if that is worked out yet.