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by rayiner
2415 days ago
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Without getting into who is a crank and who isn’t, I think the following point from the post you’re replying to really gets to the heart of my consternation: > And how can the argument both be argument by authority whilst simultaneously attacking the credibility of those authorities? If people are supposed to believe the IPCC because it’s a consensus statement, how can you then ask them to then assume the IPCC is wrong? Who is the scientific authority we’re supposed to trust more than the IPCC? Your assertion that the IPCC “gives too little consideration to tipping points” highlights the issue. The IPCC seems to have considered runaway greenhouse gas effects and rejected them as “unlikely.” Why should we disregard those conclusions? |
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In other respects, notably the structure of having a political approval stage for reports has, if that Guardian Saudi piece is to be believed, subsequently toned down those consensus views -- under pressure from home for political or economic reasons. There's also an awful lot of "he said, she said", meaning it's impossible to reach certainty from those reports. Without criticising any nation's scientific and economic representatives involved in the preparation phase, there are multiple representatives criticising that final political approval phase... Draw your own conclusions.
The upshot for those of us trying to make sense of it is IPCC tends to a very diligent presentation of the least contentious, which subsequent measurements have shown to have underestimated it on multiple occasions. Which leaves me thinking IPCC reports a best-case scenario: I believe them, it's the best consensus we have, but am not surprised if something crops up that turns out to be worse or more significant than projected. I still find that far better than had they been over-estimating impacts consistently. YMMV. :)
Specifically on tipping points, they're likely to always be something of an unknown before they actually tip. Once a threshold has been passed and an ice sheet thought safe for decades collapses, or permafrost tips into catastrophic melting it's clear the threshold was passed, and we know from hindsight. Predicting and modelling on the other hand will probably remain near impossible - we only really know after it's switched. Which is, of course, after it's too late and tipping them back effectively impossible.
That said, that old Scientific American article mentioned they would be including some consideration to threats from tipping points and non-linear effects from 2014.