this post was submitted on 13 Oct 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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[–] Risk@feddit.uk 9 points 1 year ago (2 children)

It ends on a positive though - if the world gets to net zero, then (apparently) no further warming will occur (does this mean runaway warming -from lack of reflection via ice sheets, methane release from previous permafrost zones, etcetera - is no longer expected?).

We just need to push our politicians harder. Poverty and climate are intrinsically linked - we can improve things in the everyday person's life with green investment and policy.

[–] Rhaedas@kbin.social 10 points 1 year ago

Here's the problems with net zero. First, it's a marketing term more than anything. But assuming it was an obtainable goal, it requires carbon removal techniques that have been shown by prototype and basic math to not be scalable to the task. Making another assumption that such emissions or their equivalent could be removed, we would need to go far beyond net zero into negative emissions to start chipping away at not only continued natural emissions from the mentioned runaway feedback loops already set in motion, but the historical carbon that still remains fro the last century or so of our pollution. If just net zero isn't scalable, the latter is magnitudes greater and impossible.

Net zero is the new "1.5 limit". It's an easy to remember catch phrase for a goal post on wheels. As we pass the old 1.5 mark the new one is used to distract from continued growth of population and consumption, catering to the wired tendencies of our species to procrastinate when danger isn't immediately in front of us. "They'll fix it".

I think the idea that if we can reduce our emissions warming and all that comes with it will also stop is also a subtle marketing being spread because most people don't understand that we're not the sole source of warming, we were just a small catalyst that started the reaction. And with most chemical reactions, at some point the catalyst isn't needed any more to sustain the rest of the reaction. We could stop all emissions right now (whether that be voluntary or not) and the Earth will continue to warm for decades or more just from environmental inertia and breakdown of the system, and then from the addition feedbacks that starts.

The only "fix" for the CO2 issue (which is only part of the problem, but the focus here) is to remove and sequester enough carbon to bring us down to 300 ppm or less, aka preindustrial levels. Put everything burned by our industrial age back into the ground. Entropy alone says that won't happen, calculating the numbers of how much carbon that means is mindblowing. We throw around the giga- prefix like it's nothing, and yet the total carbon we would have to remove gets into the tera- and possibly peta- levels. It's insane.

Net zero is a scam, nothing more. I'm not at all saying we shouldn't change, but don't believe anyone selling you a solution, as change means adaptation and preparation for a different and hostile world, not some science "fix" that will let us keep doing what we've always done.

I'm sure my rant that started as a short reply will get some responses of "what about ___?" Good luck showing me something new that changes the basic math of the problem. It's looking into some of these potential solutions and finding out the real problem that turned me into a hardened skeptic of anything "new". Show me the math that can tackle the numbers, then I'll consider it. In the end you can't fool Nature.

[–] Spzi@lemm.ee 3 points 1 year ago

if the world gets to net zero, then (apparently) no further warming will occur (does this mean runaway warming -from lack of reflection via ice sheets, methane release from previous permafrost zones, etcetera - is no longer expected?).

I followed the links in that quote:

Climate models have consistently found that once we get emissions down to net zero, the world will largely stop warming; there is no warming that is inevitable or in the pipeline after that point.

Neither addresses tipping points. They seem to talk about something else entirely, like wether a model assumes constant atmospheric concentration, or constant emissions, that kind of difference.

"Runaway warming", as I understand it, merely describes the outcome, the effects, while being agnostic about the causes. My current understanding is, we ruled out one possible cause. Tipping points like sea ice or methane hydrate are still on the table, AFAIK.