I'm in the KISS club: keep it simple stupid club. I prefer hard science data driven over speculations over millions of years in the past. So, I go with C3S and their data indicates that we are seeing a 0.2 degC increase annually, so, at this rate, 1 degC increase every 5 yrs. Go to their "climate pulse" page and see for yourself. The "canary in the coal mine" for me is the 1.2 trillion tons of global ice melting annually, 3.3 billion tons per day, 41 million tons PER HOUR. Any fool can see the worldwide climate collapse on the news. The fossil fuel lobby does a great, if unethical, job of obscuring the truth for mass consumption. The simple truth is that too many humans are using too many natural resources and producing too much pollution, including heat. Enjoy the entertaining speculations of the "experts" if you wish, but I grew-up watching ole Joe Friday: "just the facts, mam".
Thanks for the update. One thing I would ask though is, what does the paleoclimate record indicate, if anything, about the PACE of change? The paleoclimate record, going back millions of years, cannot be very precise in terms of time interval. Even data points every hundred thousand years would be considered extremely fine detail when you're operating on that scale. And timing is everything in terms of impact to human civilization.
It's certainly possible that increasing CO2 concentrations to 560 will result in a +8C change in temperature relative to 1850. But the real question is, how LONG does that transition take? If it takes place over a century, yeah, that is beyond catastrophic for our civilization. Like, "a few millions people surviving as hunter gatherers circa 2150" bad.
However, if it takes 10,000 years for those changes to slowly heat up the planet, well we could probably adapt to even a change that large on that type of time scale. On a long enough time scale, you don't even need to abandon and relocate buildings and cities; those things don't last that long anyway. And on that timescale, large scale atmospheric carbon capture really would seem practical. But even if not, you could end up with humanity slowly transitioning to high-latitude regions.
I'm really curious what we can say about the rate of change. Because it is really what is critical here. If we've set in motion a process that will cause the climate to reach +8C 10,000 years from now, well that really isn't actually much of a problem. Removing CO2 from the atmosphere in bulk by the end of this century is dubious. Doing it slowly over millennia, as our tech and capabilities continue to advance? That's quite doable. Hell, at that timescale, even sci fi solutions like big orbital mirrors become quite plausible. On that scale, even a +8C problem becomes something we can manage quite easily.
I would think that all that the paleoclimate data would tell us is that EVENTUALLY we would end up at the +8C level. But on a long enough time scale, we can adapt to damn near anything. The real crucial question for us and our civilization isn't the absolute amount of change, but the rate of change. We can trivially handle +8C over the next 10k years. Over the next hundred? We're completely screwed.
I said this elsewhere, from what I understand of the solutions to this crisis is a bit like rolling down the window in a car that’s already gone off the cliff. This paper is making me feel like the Earth is taking a big breath in…and we’re about to experience the exhale. I say that in reference to this particular moment from An Inconvenient Truth, wherein it was asked why the temperature swings look something like an EKG.
The math is wrong re the chances. The wider the range, the higher the probability. The 2.0-5.7 range should have a higher probability than the second biggest range (which correctly has a higher probability than the first, narrowest range). I know what you mean, but the math needs fixing (rephrasing).
The math is weird because it's a 'political' number, not really 'science'. There's a LOT of history and backstory in that 2020 report, going all the way back to the 70's.
At the 1979 Climate Summit the field split over the question of Climate Sensitivity. Basically on a 2 to 1 fault-line of Moderates VS Alarmists.
The Alarmists have held since the 70's that Climate Sensitivity would be in the +4.5°C to +6°C range.
The Moderates in the 70's assigned a range of +1.8°C to +3°C.
Over time the models of the Moderates have crept upward in their bottom range in the face of reality. The 66% range is the "best guess" as of 2020.
It reflects the Moderate Faction position that 2XCO2 will cause +2.6°C to +3.9°C of warming. Which is just 'crazy beans' if you think about it. We have gotten +1.6°C of warming using the VERY sketchy GISS baseline at 425ppm CO2. To hit +2.6°C in the Moderate models would mean that the next +140ppm CO2 causes ONLY +1.0°C of additional warming. REALLY?
In this study there was a HUGE fight about including an Alarmist model. That model is the "outlier" at +5.7°C. The Moderates didn't want to include it at all and their models assign a "less than" 5% likelihood of temperatures reaching that high at 2XCO2. As well as a less than 5% chance that warming will be as low as +2°C.
After this report, there was a BIG push to "decertify" the Alarmist model and not include it in future reports. That has been done. The next report won't include models which are so dramatically different from the others.
FYI- Many of the people at the 1979 event are still alive and influencing the field.
It's about confidence intervals. The way I read your post, I think what you mean to say is this:
The chance of staying inside a +2.6–3.9°C increase is 66%
The chance of staying inside a +2.3–4.5°C increase is 95%
The chance of falling outside of a +2.0–5.7°C increase is 5%
Because the chance of staying inside a +2.0–5.7° increase must logically be greater than the chance of staying inside a narrower window of a +2.3–4.5°C increase.
But maybe I misunderstood; in which case, never mind :)
The thing I've been thinking about recently is even with your distinction between moderates and alarmists, moderate outcomes would still be.... well, alarming! How much worse if the alarmists are correct? Goddamn.
No sir, what I find crazy is that number, 0.81, is just the best fit from now until that magical 2100. There won’t be anything linear about our futures.
And that's if it turns out to be linear. It likely will be front end loaded though, so the next 5 years will be the worst . . . Maybe 2 degrees for the next decade.
It's likely to be 8 degrees by 2100? Who will still be around at 4.5 degrees? When will we hit catastrophic temperatures? To me, this looks like a death sentence for society as we know it. And what else would a moderate scientist say? "Fuuuuuuuck! That looks bad, I guess I was wrong"?
I'm in the KISS club: keep it simple stupid club. I prefer hard science data driven over speculations over millions of years in the past. So, I go with C3S and their data indicates that we are seeing a 0.2 degC increase annually, so, at this rate, 1 degC increase every 5 yrs. Go to their "climate pulse" page and see for yourself. The "canary in the coal mine" for me is the 1.2 trillion tons of global ice melting annually, 3.3 billion tons per day, 41 million tons PER HOUR. Any fool can see the worldwide climate collapse on the news. The fossil fuel lobby does a great, if unethical, job of obscuring the truth for mass consumption. The simple truth is that too many humans are using too many natural resources and producing too much pollution, including heat. Enjoy the entertaining speculations of the "experts" if you wish, but I grew-up watching ole Joe Friday: "just the facts, mam".
Thanks for the update. One thing I would ask though is, what does the paleoclimate record indicate, if anything, about the PACE of change? The paleoclimate record, going back millions of years, cannot be very precise in terms of time interval. Even data points every hundred thousand years would be considered extremely fine detail when you're operating on that scale. And timing is everything in terms of impact to human civilization.
It's certainly possible that increasing CO2 concentrations to 560 will result in a +8C change in temperature relative to 1850. But the real question is, how LONG does that transition take? If it takes place over a century, yeah, that is beyond catastrophic for our civilization. Like, "a few millions people surviving as hunter gatherers circa 2150" bad.
However, if it takes 10,000 years for those changes to slowly heat up the planet, well we could probably adapt to even a change that large on that type of time scale. On a long enough time scale, you don't even need to abandon and relocate buildings and cities; those things don't last that long anyway. And on that timescale, large scale atmospheric carbon capture really would seem practical. But even if not, you could end up with humanity slowly transitioning to high-latitude regions.
I'm really curious what we can say about the rate of change. Because it is really what is critical here. If we've set in motion a process that will cause the climate to reach +8C 10,000 years from now, well that really isn't actually much of a problem. Removing CO2 from the atmosphere in bulk by the end of this century is dubious. Doing it slowly over millennia, as our tech and capabilities continue to advance? That's quite doable. Hell, at that timescale, even sci fi solutions like big orbital mirrors become quite plausible. On that scale, even a +8C problem becomes something we can manage quite easily.
I would think that all that the paleoclimate data would tell us is that EVENTUALLY we would end up at the +8C level. But on a long enough time scale, we can adapt to damn near anything. The real crucial question for us and our civilization isn't the absolute amount of change, but the rate of change. We can trivially handle +8C over the next 10k years. Over the next hundred? We're completely screwed.
Well that is the BIG question now isn't it?
I said this elsewhere, from what I understand of the solutions to this crisis is a bit like rolling down the window in a car that’s already gone off the cliff. This paper is making me feel like the Earth is taking a big breath in…and we’re about to experience the exhale. I say that in reference to this particular moment from An Inconvenient Truth, wherein it was asked why the temperature swings look something like an EKG.
Thank you for this well-written update. I look forward to being further informed and horrified by you soon.
Studying this stuff has really changed my life. I appreciate each day more knowing that peace and abundance may be harder to find in the future.
The math is wrong re the chances. The wider the range, the higher the probability. The 2.0-5.7 range should have a higher probability than the second biggest range (which correctly has a higher probability than the first, narrowest range). I know what you mean, but the math needs fixing (rephrasing).
The math is weird because it's a 'political' number, not really 'science'. There's a LOT of history and backstory in that 2020 report, going all the way back to the 70's.
At the 1979 Climate Summit the field split over the question of Climate Sensitivity. Basically on a 2 to 1 fault-line of Moderates VS Alarmists.
The Alarmists have held since the 70's that Climate Sensitivity would be in the +4.5°C to +6°C range.
The Moderates in the 70's assigned a range of +1.8°C to +3°C.
Over time the models of the Moderates have crept upward in their bottom range in the face of reality. The 66% range is the "best guess" as of 2020.
It reflects the Moderate Faction position that 2XCO2 will cause +2.6°C to +3.9°C of warming. Which is just 'crazy beans' if you think about it. We have gotten +1.6°C of warming using the VERY sketchy GISS baseline at 425ppm CO2. To hit +2.6°C in the Moderate models would mean that the next +140ppm CO2 causes ONLY +1.0°C of additional warming. REALLY?
In this study there was a HUGE fight about including an Alarmist model. That model is the "outlier" at +5.7°C. The Moderates didn't want to include it at all and their models assign a "less than" 5% likelihood of temperatures reaching that high at 2XCO2. As well as a less than 5% chance that warming will be as low as +2°C.
After this report, there was a BIG push to "decertify" the Alarmist model and not include it in future reports. That has been done. The next report won't include models which are so dramatically different from the others.
FYI- Many of the people at the 1979 event are still alive and influencing the field.
It's about confidence intervals. The way I read your post, I think what you mean to say is this:
The chance of staying inside a +2.6–3.9°C increase is 66%
The chance of staying inside a +2.3–4.5°C increase is 95%
The chance of falling outside of a +2.0–5.7°C increase is 5%
Because the chance of staying inside a +2.0–5.7° increase must logically be greater than the chance of staying inside a narrower window of a +2.3–4.5°C increase.
But maybe I misunderstood; in which case, never mind :)
The thing I've been thinking about recently is even with your distinction between moderates and alarmists, moderate outcomes would still be.... well, alarming! How much worse if the alarmists are correct? Goddamn.
I think this, taking about getting to 8C by 2100, is like .81C of warming per decade from here on out.
Sounds crazy right?
But, we just warmed up about +0.5°C in four years.
No sir, what I find crazy is that number, 0.81, is just the best fit from now until that magical 2100. There won’t be anything linear about our futures.
And that's if it turns out to be linear. It likely will be front end loaded though, so the next 5 years will be the worst . . . Maybe 2 degrees for the next decade.
Now is the time to, "smoke em, if you got em". Our world is about to experience severe shortages of EVERYTHING.
I'm out in front of this one, enjoying and grieving at the same time while we still can.
It's likely to be 8 degrees by 2100? Who will still be around at 4.5 degrees? When will we hit catastrophic temperatures? To me, this looks like a death sentence for society as we know it. And what else would a moderate scientist say? "Fuuuuuuuck! That looks bad, I guess I was wrong"?