this post was submitted on 20 Aug 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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[–] NoiseColor@startrek.website 18 points 3 months ago (2 children)

Maybe it's because climate scientists have been underestimating effects for decades so they didn't lose grants for looking alarmist.

[–] mindlesscrollyparrot@discuss.tchncs.de 12 points 3 months ago (1 children)

Have they?

"In this case, their very specific prediction was that warming of between 1.5°C and 4.5°C would accompany a doubling of atmospheric CO₂" https://theconversation.com/40-years-ago-scientists-predicted-climate-change-and-hey-they-were-right-120502

Isn't the problem more that people have been reading that and assuming that it means 3°, not 'possibly 4.5°' ?

That said, the study there seems to assume that the effects are roughly linear, ie. that there are no tipping points.

[–] NoiseColor@startrek.website 4 points 3 months ago (1 children)

I don't want to go into specific predictions because there are too many. But generally, scientists are very conservative with their predictions, because they don't want to lose grants. It's safe to hide behind numbers and give low estimates.

I hear what you're saying, but I think the real problem is the policy makers, who are without doubt choosing to use the least scary predictions, and pushing even those targets back when they fail to achieve them.

[–] hannesh93 4 points 3 months ago (1 children)

That's the thing - if science is projecting something for the future nothing is 100% certain - so they have to widen the range in order to have a statement with a lower number that's "90% certain" even if there's a very high chance that it's going to be way worse

[–] NoiseColor@startrek.website 5 points 3 months ago (1 children)

Absolutely, but if you ask climate scientists, in private, what they think the numbers are saying, they will tell you a very different story.

[–] whoisearth@lemmy.ca 6 points 3 months ago (1 children)

I would guess we've been fucked for at least a couple of decades by now. In their need to "reach a consensus" we have been sold an unrealistic narrative of hope lol

[–] NoiseColor@startrek.website 3 points 3 months ago

Yes, well phrased. All though I think there was hope. There is always hope, but none of the deciders care or have cared.