this post was submitted on 01 Aug 2023
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The technical summaries are still ultra-conservative in their predictions and whilst their latest updates finally factor in some tipping points, the vast majority are left out to avoid alarm. To give you just one example, they predict the AMOC will not collapse before 2100. Take a look at the current North Atlantic temperatures and tell me in good faith that this is a sensible prediction.
Tautological argument, see above.
I mean the graphic you posted is literally entitled "Potential contribution to net emissions reduction, 2030". And I think you vastly underestimate what it would take to sequest enough carbon to make any kind of difference.
Just realised you're a mod here, why on earth are you allowing/posting conjecture such as that climate pessimism blog post if the purpose of this sub is to be truthful? It's the biggest load of drivel short of denial I've read with regards to the climate. A whole essay from what I can only presume is a fossil fuel industry shill with literally nothing to back up any of its claims.
They represent a consensus summary of the published academic literature from before the cutoff date. A study which came out after the last report is naturally not included.
They're literally about emissions reduction, and quantifying it. Getting the maximum reduction would mean something like a WWII-style mobilization. I don't think I'm underestimating that.
Oh naturally, I think you've hit the nail on the head there. Tell me, how does one conduct a scientific study on feedback loops which haven't happened yet? Then tell me how many peers would be willing to risk their funding to verify such a pessimistic prediction?
I know they're about emissions reduction, I didn't say they weren't and I don't understand your point. All I'm saying is that it's all well and good stating what we need but the feasibly of implementation is laughable.
I suggest you look into the resources required to extract the smallest amounts of carbon from the atmosphere. To quote Dr Hugh Hunt of Cambridge...
Completely agree with you re the WWII mobilisation. That would require every government in the world to work together in actively worsening the lives of their citizens. Not exactly a vote winner is it?
You model them. A great example was the ice-albedo feedback, where you could measure the albedo of ice, and the albedo of open water and bare ground, and reach clear conclusions about how losing ice would create differential warming in the arctic.
The modeling work won't ever be perfect, but it's good enough to have incredible predictive power.
Sorry, couldn't resist.
And yet still the ice is melting faster than expected and faster than that model predicted, because, as you explain, the models are inaccurate (overly conservative in nature as all scientific studies on complex systems tend to be).
Ice sheet dynamics have been an area where scientists haven't converged on agreed-upon models. So yes, not everything gets there, but an awful lot does. As I said above, enough to be useful.
You seem to keep supporting my point.
The models are conservative, the peer review process is long and we're rapidly running out of time.
It's more complicated than that. The temperature modeling is roughly right. Secondary effects aren't as well modeled, and surprise is a lot more likely there.
Yes it's obviously way more complex than that. For instance, there are a lot of additional warming factors that haven't been included in current studies or "suprises" to use your euphimism.
The big ones we expect to play a role in the next few decades are in there though. That's enough to be pretty useful.
Pretty useful, in that they predict warming but not necesarily accurate.
I disagree, we do not know how well feedbacks are modelled or even if the models include all significant feedbacks. Correct me if you've found anything that contadicts these:
The albedo effect problem you mentioned is likely to happen faster than predicted as the latent heat of melting isn't considered. The heat it requires to melt all that ice will instead heat the water around the remaining ice at a much higher rate.
IPCC doesn't account for the aerosol cooling effect. If we cut our emissions there would likely be a rapid warming of 0.5-1.0°C within a couple of years as particulates in the air are blocking less sunlight.
The ice sheets don't melt at a steady rate. Last time this much carbon dioxide was in the atmosphere they ended up retreating 600m per day which should affect predictions.
Not strictly a feedback loop but worth mentioning... The earth contains less than 20% of the copper needed to produce the renewables required to replace fossil fuels over the next 20 years, about 20% of the required nickel and less than 2.5% of the required lithium.
Just no. Ice sheet response tends to be parameterized, where a computationally simple approximation is used, including this.
This is complete nonsense. They've been accounting for it for ages. That's where figures like this come from.
This is well known, and widely discussed.
This appears to be from a single study of a particular set ice sheets off Norway which were grounded below sea level. Thwaites is like that, but much of the big ice sheets are not. Ice melt isn't some simple thing which will happen at the same rate everywhere.
This is a serious misreading of what's going on. There's enough in the earth's crust, but trying to depend only on existing mines would be a bottleneck. That's why a ton of new mines are opening.