IPCC climate crisis report delivers ‘final warning on 1.5C’ • Hacker News Board

Re: IPCC climate crisis report delivers ‘final warning on 1.5C’

#121

Post by mrmanner » Mon, Mar 20, 2023, 3:59 PM UTC

mrmanner wrote: post #117

kypro wrote: post #59

Assume we hit 1.5C and "nothing happens" does this help the cause? While I'm very concerned about how unchecked climate change could impact future crop yields I also worry that having a hard line like this probably won't help convince anyone, and could counter intuitively act as a "I told you so" for climate denialists when the world doesn't fall apart as soon as we hit 1.5C. A lot of the more convincing arguments I…

The problem here is that we just aren’t cut out to understand delayed consequences. The society we build today decided co2 levels tens of years into the future, affecting temperature for yet more years into the future, affecting society for very long time. One effect of this is that consequences may be locked in long before we see them. Propagandists love to exploit this by saying things like “there’s still time - ju…

Another interesting thing: one of many reasons behind the “hard line” at 1.5 degrees is that this is the level of warming were models and simulations of consequences have reasonable certainty. Beyond that level there are more unknowns and more less certainty.

So 1.5 degrees should be an important target if good models are important. But, it turns out, certainty isn’t what we’re after.

Re: IPCC climate crisis report delivers ‘final warning on 1.5C’

#122

Post by bertil » Mon, Mar 20, 2023, 4:03 PM UTC

Retric wrote: post #18

Rygian wrote: post #8

For anyone interested in what 1.5C represents, I can't recommend enough the Climate Fresk [1] exercise. It's not just the droughts and floods, the heatwaves, the changes in birds, insects, crop yields, … Include permafrost melting and releasing greenhouse gasses, civil unrest in populated areas that won't be livable anymore, unstable food production, and quite a few other causes and consequences. It's a feedback loop…

Overstating impact is detrimental to the cause. > decimated 1.5C will be bad, but it won’t directly kill 800+ million people in a short timeframe. People simply don’t respond to harm spread across 100 years the way they react to harm concentrated into a few large events.

OK: how will their respond?

Imagine you live in a valley where elderly people die of heat stroke every summer: 100 three years ago, 500 the summer after, 2,000 last summer. Your parents are 70 and 71 and barely made it. You immigrate, with your children, right? To where? The big city with worse heat management?

Repeat with peasants who can’t grow crops without expensive feedstock, or pig farmers whose water supply is dry. Where will they go?

People will want to flock to places that are currently openly considering tall walls and machine guns to prevent immigration — and that’s when thousands are coming at a time.

You think that having several millions every year will not make that situation a lot more tense?

Re: IPCC climate crisis report delivers ‘final warning on 1.5C’

#123

Post by taylodl » Mon, Mar 20, 2023, 4:03 PM UTC

scottLobster wrote: post #104

geysersam wrote: post #51

Earlier quoted context omitted.

So is understating the impact. This take is seriously dangerous. "1.5C is not so bad, chill people" When the fact is - we don't know the impact - if we go beyond 1.5. What we do know (because it's already very much measurable) is that much of the worlds glaciers will melt, causing drought. What we do know is that eventually the sea levels will rise and drown many extremely valuable coastal areas.

I'd argue we have no idea what will happen when the glaciers melt, given the lack of accurate climate change predictions to date. We have a lot of models that have historically proven very incomplete with no reason to believe they're any more complete now. The oceans rising is more a problem, but it's not going to end human civilization and will happen slowly enough that adaptation is possible, albeit expensive. "Dro…

Oh my Sweet Summer Child, you really have an unplaced faith in humanity - especially given our track record. "The sky is shifting" - is a hand-wave to the life-changing impacts headed our way and what our collective response to those impacts will be. Look how nuts people are getting over what are mere trivialities in comparison. Wait until there's crop failures threatening our food supply, fresh water supplies being threatened, property damage on the scale never seen in history, the religious blaming the non-religious for all our woes - the list goes on.

That's some "shifting."

Re: IPCC climate crisis report delivers ‘final warning on 1.5C’

#124

Post by dathos » Mon, Mar 20, 2023, 4:04 PM UTC

shrubble wrote: post #62

So, does this apply to China, which is burning more coal than ever? The UN secretary general, António Guterres, said: “This report is a clarion call to massively fast-track climate efforts by every country and every sector and on every timeframe. Our world needs climate action on all fronts: everything, everywhere, all at once.”

This is not one of those problems that goes away by pointing a finger.

Re: IPCC climate crisis report delivers ‘final warning on 1.5C’

#125

Post by Retric » Mon, Mar 20, 2023, 4:06 PM UTC

timr wrote: post #113

Retric wrote: post #95

Earlier quoted context omitted.

Every hour in operation 2GW of natural gas emit the same CO2 as 1GW of coal. In terms of how quickly we hit 2.5C of global warming that makes a big difference on its own. However, large steam turbines simply take a lot of energy to warm up to operating temperature. This means simply turning coal power plants on and off releases lots of CO2. This makes a huge difference as we add wind and solar because you can turn na…

> However, large steam turbines simply take a lot of energy to warm up to operating temperature. Boilers, not turbines. The boilers at a coal plant are gigantic -- 5+ story hunks of metal the size of city buildings. They don't turn on/off on demand. The whole system is complex, of course, but the boilers are giant boxes of fireball that flash-vaporize water using pulverized coal at ~500C and 200+ bar of pressure [1].…

I was referring to a nuance that’s easy to overlook. As you say the coal power plant needs to heat up a boiler to operating temperatures before it’s turbine can generate power. Yet, that’s still not enough for maximum efficiency.

Cold pipes and turbine blades steal energy from the steam. Similarly the boiler is less efficient when fed cold water vs hot water from the condenser. Thus the startup process is more involved than just how long it takes to start generating power.

The most efficient coal power plants are actually double-reheat which takes even long to get up to optimal conditions. https://www.sciencedirect.com/science/article/abs/pii/S03605...

Re: IPCC climate crisis report delivers ‘final warning on 1.5C’

#126

Post by zug_zug » Mon, Mar 20, 2023, 4:08 PM UTC

burkaman wrote: post #64

kypro wrote: post #59

Assume we hit 1.5C and "nothing happens" does this help the cause? While I'm very concerned about how unchecked climate change could impact future crop yields I also worry that having a hard line like this probably won't help convince anyone, and could counter intuitively act as a "I told you so" for climate denialists when the world doesn't fall apart as soon as we hit 1.5C. A lot of the more convincing arguments I…

Can you quote something from the report that you feel was overly emotional?

Well I think climate change is objective fact, but this link is wildly emotional.

"Final Warning" "act now or it's too late" sounds like a late-night infomercial selling me something.

If I were running the report I'd try to write it in a manner that is scientific and thus emotionally indifferent to every outcome. Science doesn't care whether any special dies or not (humans or not). If you can't look at climate science with an indifference to the death of the species, you probably can't run statistics neutrally, which gives a lot of room for doubt (fair or not).

Re: IPCC climate crisis report delivers ‘final warning on 1.5C’

#127

Post by ch4s3 » Mon, Mar 20, 2023, 4:08 PM UTC

mrmanner wrote: post #107

ch4s3 wrote: post #68

Earlier quoted context omitted.

Is that true? And assuming it is, the model was still wrong as an assumption of business as usual is part of that model. But I don't see how any of that could have prevented a glacier from melting by 2023 or the world from being "doomed" by 2018.

The model didn’t _assume_ business as usual. It explained the consequences of business as usual.

I'm being charitable by saying "model". Greta was just making shit up when claiming the world would be doomed in 5 years back in 2018. But models don't explain what will happen in the future, they predict and they bake in a lot of assumptions. Any model that predicted an ice free Glacier National Park by 2023 was simply wrong, and it was doubly wrong to post signage that stated the prediction as fact.

Re: IPCC climate crisis report delivers ‘final warning on 1.5C’

#128

Post by timr » Mon, Mar 20, 2023, 4:09 PM UTC

Retric wrote: post #125

timr wrote: post #113

Earlier quoted context omitted.

> However, large steam turbines simply take a lot of energy to warm up to operating temperature. Boilers, not turbines. The boilers at a coal plant are gigantic -- 5+ story hunks of metal the size of city buildings. They don't turn on/off on demand. The whole system is complex, of course, but the boilers are giant boxes of fireball that flash-vaporize water using pulverized coal at ~500C and 200+ bar of pressure [1].…

I was referring to a nuance that’s easy to overlook. As you say the coal power plant needs to heat up a boiler to operating temperatures before it’s turbine can generate power. Yet, that’s still not enough for maximum efficiency. Cold pipes and turbine blades steal energy from the steam. Similarly the boiler is less efficient when fed cold water vs hot water from the condenser. Thus the startup process is more involv…

Yes, definitely. Not disagreeing with you, just adding color and an anecdote.

The broader point that we can't just turn these things on and off is 100% correct, and one of the (many) things that people don't understand when talking about the power system and emissions.

I don't know the details of wind and solar, but any system that deals with hundreds-to-thousands of megawatts can't just be spun up on a dime. Make a mistake, and things blow up.

Re: IPCC climate crisis report delivers ‘final warning on 1.5C’

#129

Post by specialist » Mon, Mar 20, 2023, 4:13 PM UTC

Retric wrote: post #18

Rygian wrote: post #8

For anyone interested in what 1.5C represents, I can't recommend enough the Climate Fresk [1] exercise. It's not just the droughts and floods, the heatwaves, the changes in birds, insects, crop yields, … Include permafrost melting and releasing greenhouse gasses, civil unrest in populated areas that won't be livable anymore, unstable food production, and quite a few other causes and consequences. It's a feedback loop…

Overstating impact is detrimental to the cause. > decimated 1.5C will be bad, but it won’t directly kill 800+ million people in a short timeframe. People simply don’t respond to harm spread across 100 years the way they react to harm concentrated into a few large events.

> won’t directly kill 800+ million people in a short timeframe

I'd rather we not find out.

Plan for the worst, hope for the best.

Re: IPCC climate crisis report delivers ‘final warning on 1.5C’

#130

Post by ewjt » Mon, Mar 20, 2023, 4:13 PM UTC

johnnymorgan wrote: post #69

thwayunion wrote: post #40

Earlier quoted context omitted.

If climate models were predicting the temperature of your city on March 21, 2120 then your intuition here would be wise. But that is not at all what these models are predicting. They are predicting global average annual temperatures and other gross, planet-scale statistics. "Average annual global temperature in a given year" and "temperature in my city tomorrow" are fundamentally very different types of predictions.…

The point he is making is the disconnect between models and reality. Also when are people held accountable for their models being wrong and the output that comes from that. Climate models has a terrible track record and have failed to materialize over and over again. We have environmental crises all over the place which we should be focused on. The two are not the same thing and climate activism seems to not care abo…

Please back up the claim "climate models has a terrible track record" and qualify the word 'terrible'.

Casting blame is a common denier tactic [1] used despite the models being useful and accurate [2].

The "whataboutisms" you mention are another common tactic. [3] Blaming EV batteries is a red herring; they have much lower lifecycle emissions than gas-based engines. [4]

[1] https://skepticalscience.com/climate-models.htm [2] https://climate.nasa.gov/news/2943/study-confirms-climate-mo... [3] https://www.cambridge.org/core/journals/global-sustainabilit... [4] https://arstechnica.com/cars/2021/07/electric-cars-have-much...