this post was submitted on 17 Mar 2024
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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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[–] 0110010001100010@lemmy.world 130 points 8 months ago (4 children)

Hundreds of years of innovation in water travel, and we come back to a sail. Granted, a metal one, but still a fucking sail.

[–] Ephera@lemmy.ml 71 points 8 months ago (1 children)

Hard to beat the efficiency of just having energy delivered to you for free...

[–] NotMyOldRedditName@lemmy.world 40 points 8 months ago

Those damned sails stealing the earth's winds for free.

Global warming you know why it's happening? Because the sails are all stopping the global winds! No winds to blow the heat away and it all warms up! BAN SAILS TODAY to MAKE AMERICA GREAT AGAIN!

[–] protist@mander.xyz 56 points 8 months ago* (last edited 8 months ago)

The scale of a sail needed to propel a giant cargo ship is really quite a bit different from what you might imagine on an old frigate, aka a "pirate ship." Making a sail that large out of traditional materials is not feasible, and would require a ton of people to operate it. One of these monstrosities is staffed by probably less than 20 people, and labor is expensive, so this sort of computer operated sail can be both feasible and cost effective, whereas old school type sails were not

[–] NegativeInf@lemmy.world 37 points 8 months ago

What's old is new again. Time is a flat circle. But really, technology has a good habit of compounding gains. One new idea applied to a hundred old ones really gets innovation running hot.

[–] ColeSloth@discuss.tchncs.de 10 points 8 months ago (2 children)

There's a reason they quit, though. It's slow and doesn't let you go in every direction. The midline area of earth has winds that move mostly towards west, while the north and south portions blow mostly east.

For those curious, these sails save 12 tons per day. The average cargo ship uses around 200,000 tons per day, so around 6% better fuel economy.

[–] Lorgres@lemmy.world 17 points 8 months ago* (last edited 8 months ago) (1 children)

Thanks for putting it into relation to daily use. 200,000 is not realistic though. Just had a google and found this source citing up to 400 metric Tons/day

https://maritimepage.com/fuel-consumption-how-much-fuel-cargo-ship-use/

12 is 0.6% of 200,000 btw

[–] ThrowawayPermanente@sh.itjust.works 9 points 8 months ago (1 children)
[–] Tja@programming.dev 4 points 8 months ago

This is the correct calculation (although the 200k figure is wrong)

[–] zaphod@feddit.de 7 points 8 months ago (1 children)

The 12 tons are a best case and they represent 37% of this ship's fuel consumption, that would be ~32.5 tons a day, on average it saved 3.3 tons, ~10%.

[–] Paragone@sh.itjust.works -1 points 8 months ago

Which makes the break-even point for such wingsails, which cost one hell of alot more than a few tonnes of fuel did .. rather far-away/long-term, doesn't it?


There was also a system using huge parachute-kite things, on carbon-nanotube-ropes, fired up into the sky with rocket-assist, and the things could apparently pull the ship, quite effectively...

.. the service-subscription the ship was supposed to pay-for gave them the optimal route for fuel-savings vs time-to-get-there..

here, it was sorta like this, but the kite-sail looked different, and I'm pretty-sure they were saying something about nanotube cable for the kite, and it wasn't just a concept, it was actually-working...

https://marinersgalaxy.com/giant-kite-pulls-ship-across-atlantic/


I seem to remember that at the beginning of covid, some shipping companies just shortened the bulbs on their hulls, to optimize for a slower cruising-speed, and saved money that way..

again, where's the break-even on it