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How Climate Scenarios Lost Touch with Reality

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51–60 of 85 posts

Re: How Climate Scenarios Lost Touch with Reality

#51
This takes a long time to get to the point, but it's hard to deny this part of the article?

> It associated the RCP scenarios with not just plausibility but also likelihoods when it labeled the scenario leading to the greatest amount of climate change, called RCP8.5 (indicating a radiative forcing of 8.5 W/m2 in 2100), as the single business-as-usual scenario of the set.

> For instance, RCP8.5 projects to 2100 a six-fold growth in global coal consumption per capita, while the International Energy Agency and other energy forecasting groups collectively agree that coal consumption has already or will soon peak. Also, RCP8.5 foresees carbon dioxide emissions growing rapidly to at least the year 2300 when Earth reaches more than 2,000 ppm of atmospheric carbon dioxide concentrations. But again, according to the IEA and other groups, fossil energy emissions have likely plateaued, and it is plausible to achieve net-zero emissions before the end of the century, if not much sooner. Today, projections that carbon dioxide emissions from fossil fuels will increase dramatically for the next 50, 100, or 300 years are simply implausible.

Re: How Climate Scenarios Lost Touch with Reality

#52
post #7

This is waaaaaaaaay too many words when all they want to say is “RCP8.5 is now unrealistic given progress towards climate goals, and the “business as usual” scenario should be updated in the next IPCC report”

Thank you. This seemed like it was written by a student who was saying the same thing over and over in order to satisfy a 4,500-word target, and I was wondering what I was missing.

It’s interesting to understand how these RCPs came into existence, in addition to their flaws.

Re: How Climate Scenarios Lost Touch with Reality

#53
post #38

Earlier quoted context omitted.

[flagged]

Perhaps a reply to the wrong comment? In what way were average people mentioned? Who are the villains? Who's going after them?

And why average people? If we waited for the average person to care about problems then that would usually cause action to be taken much later than ideal.

Re: How Climate Scenarios Lost Touch with Reality

#54

Earlier quoted context omitted.

I get the sense that they are trying very carefully not to sound like climate change denialists, so that they won't get conflated with people much further from the scientific consensus. If they just said "the IPCC models are BS," they would likely be dismissed out of hand, at least in the scientific community.

Pielke Jr is a climate-action "denialist" from a long way back, no? (claims to accept the science but then concludes there's nothing we can do about it for the foreseeable future other than adapt. This article seems to be saying "well ok some of the changes we've made are making a difference to emissions, but now there's no real need to make any more...").

You’ve substituted “climate change denialist” for “climate action denialist”.

Why?

Re: How Climate Scenarios Lost Touch with Reality

#55
post #31

Eeh. Misguided article. The article itself starts by recognizing the challenge of making scenarios because of the feedback loop they embody. Then seemingly forgets about all that and basically says "coal has likely peaked already, why are assuming it will grow in the future?" Well, because of that feedback loop. Coal is still a cheap way of making energy, as it is in the business-as-usual economics of the scenarios.…

Likes like coal production has increased since the 1990s https://ourworldindata.org/grapher/coal-production-by-countr...

Re: How Climate Scenarios Lost Touch with Reality

#56
post #27

I'm not clear on the take away. Are the models wrong? Or is it more that the projections were off? Put differently, are the models precise but inaccurate or both? If inaccurate only, are they still instructive?

The article argues that the models are still using baselines from the 90s, while the world as it is today has already made significant progress toward decarbonizing industry. Therefore the projection are far more onerous than they should be.

I get that, but how much more? And what is the reason for the error?

That is, are the models bad, or the scenarios? The models don't control the inputs, after all. If it is just the inputs are different from actuals, that is very different from the outputs are wrong

Re: How Climate Scenarios Lost Touch with Reality

#57

Earlier quoted context omitted.

Pielke Jr is a climate-action "denialist" from a long way back, no? (claims to accept the science but then concludes there's nothing we can do about it for the foreseeable future other than adapt. This article seems to be saying "well ok some of the changes we've made are making a difference to emissions, but now there's no real need to make any more...").

You’ve substituted “climate change denialist” for “climate action denialist”. Why?

Only because I don't believe he's ever denied climate change was happening or that if it is it's not our fault, which are the usual first two phases of denialism.

Re: How Climate Scenarios Lost Touch with Reality

#58

Earlier quoted context omitted.

The article argues that the models are still using baselines from the 90s, while the world as it is today has already made significant progress toward decarbonizing industry. Therefore the projection are far more onerous than they should be.

We're probably using more carbon now, then in the 90s. You have to look at the total carbon output of the world.

Not the point. We use less carbon today than the scenarios looking forward to today did. Such that our path forward does not start from where many models assume.

Yes, you have to look at the whole picture. But you also have to look from where you are. Not where someone else thought you could be. Right?

Re: How Climate Scenarios Lost Touch with Reality

#59
post #7

Earlier quoted context omitted.

Thank you. This seemed like it was written by a student who was saying the same thing over and over in order to satisfy a 4,500-word target, and I was wondering what I was missing.

Unfortunately I feel like submissions on the site, as well as general content online, of the same type for significantly less academic subjects (this new cool web framework I'll spend 6000 words writing about) are the norm now. And before anyone says so, no it has nothing to do with the supposed lessened attention span smartphones have caused. I'm not wasting 15 minutes of my life reading about social media recommend…

Ever since I saw a comment on HN about low information density on the internet, I haven’t been able to unsee it. They were commenting on a YouTube video that had an 8-second bit of content but was nearly 2 minutes long. But it’s so much worse than that.

Recipes tell you how their great grandmother moved to the Americas and made the first apple pie ever. And then detail the entire history of apples and how to make the entire recipe. And then, 70% of the way down the page, right before the comment section, is what you wanted at first glance: what’s in this pie, and how long will it take me to make?

It’s everywhere.

Re: How Climate Scenarios Lost Touch with Reality

#60
The reason RCP 8.5 remains relavant despite changes to the mix is that our historical CO2 output is closer to it than of the other scenarios. Its predictions remain the most likely after 15 years from this scenario being created given what we have already released into the atmosphere. RCP 8.5 is the scenario best tracking the actual emissions of the last 15 years.

https://www.pnas.org/doi/10.1073/pnas.2007117117

Relevant image: https://www.pnas.org/cms/10.1073/pnas.2007117117/asset/56610...

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