Edited quotes
I see that you have all been having a lot of fun debunking my claims. And perhaps they needed debunking, who knows.
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So global warming. Yes, it's a disaster. No, we are not going to stop it. So how much of a disaster is it going to be?
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The only true threat to global civlisation would be a large and consistent disruption in food production. And I'm not seeing anybody predicting such an outcome (although it does seem to me to be at least a possibility).
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Another of the papers he links to makes some properly dystopian claims, e.g. that CO2 "... is rapidly heading towards levels last seen some 50 million years ago — in the Eocene — when temperatures were up to 14 °C higher than they were in pre-industrial times."
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Yes I know that end-of-world prophecies are exciting and lot's of people seem to wish for some sort of apocalypse. I don't
binntho - Disagreement is not opprobrium or personal attack. You are well known in this forum for providing thoughtful opinion and insight. If some nut job jumped onto the forum and wrote that disrupting the planetary climate would have minor effect on well being, people would just dismiss it and not bother to respond with forceful argument. It is exactly because you do seem intelligent, informed, and curious that folks weigh in to redirect what I (and I presume others too) see as a colleague who is engaging in delusional thinking. We argue with you because we care and trust that you have the ability to change your mind. That requires the same of us. I submit that the facts do not support your position.
RE: "No, we are not going to stop it."
It is not a yes/no situation. Significant damage has already been done. Dorian/Great Barrier Reef/2003 Eur. heat wave, etc etc ad nauseum. I personally don't see how there is ANY chance of not breeching 1.5 C, so I wish IPCC would stop paying it lip service. But we still have the ability to halt the destruction, pain, and loss caused at 2C or 3C vs. 4C. By numerous analyses by people who dedicate their professional lives to understand this stuff, getting to 4C could result in a runaway situation where human action is overwhelmed by natural reinforcing feedback mechanisms.
RE My #3 citation quoting Lenton et al. Nov. 2019 article in Nature --
The list of authors for that piece includes many widely recognized top-tier experts (published in the 1st or 2nd most respected peer-reviewed journal). "Trust the experts" has fallen out of favor now that with the internet anybody can "publish" any thought that bubbles up through their brain (self included).
But facts and expertise still matter. I still trust the experts when I have a toothache or when the relevant experts tell me that the global ecosystem on which I and my children are utterly and entirely dependent is being irrevocably altered. You misunderstand and misrepresent their statement about potential for a runaway temperature increase. They did not say that human emissions alone would drive CO2 to 2500ppm. But there are powerful feedbacks that can and have done exactly that. That scenario is not merely hypothetical, it has happened before and can happen again. It is an engineering analysis of physical properties, not a prophecy based on philosophy. To ignore factual warnings by experts is self-destructive.
Heeding warnings of impending destruction and attempting to avert it by spreading the alarm is not wishing for it. The scale of response needed to reinvent and replace our energy system on a global scale is daunting and difficult. To succeed will require unprecedented concerted action across political, ethnic, economic and other boundaries. Humanity faces a sink or swim crisis.
RE: Not finding scientific evidence for climate change impact on agriculture
All I can say is look again. It's there. Lots of it. Reduced crop yields as cropping areas exceed tolerances for plants already near their thermal maximum. A CO2 fertilization effect that only allows crop plants more vegetative growth if water, temperature stability and other needs that are threatened by climate change are controlled. And even if that vegetative growth does occur, it largely acts to dilute food nutrient density instead of increasing it. As for, "we'll just move cropping areas north with the shifting isotherm", it isn't that simple. The solar radiation supply required for photosynthesis is not moving north, nor are the soil resources farther north the same as current ag production zones. Add in altered, and more likely more erratic, precipitation patterns and the prospects for simply shifting north become even more challenging. As for that CO2 fertilization effect, here is some more bad news -- weeds are better adapted to benefit from it than crops. Weeds already outpace insect and disease pests for crop production losses.
There may be localized benefits for a few cool ag production areas where water supply is not reduced. I happen to live and work in one such area. But even here the cost-benefit ratio is not necessarily positive. For the planet overall, the studies show net negative impacts that increase with additional warming. The result is stalled or reversed productivity when we need the opposite to feed a larger population. = Supply-Demand Train wreck.
Any "ism" taken to an extreme becomes destructive. Capitalism run amok becomes Nazi fascism. Socialism run amok becomes Animal Farm Big Brother 1984 totalitarian communism. Religious isms run amok become the Crusades,the Jonestown massacre, or ISIS. Maybe Humanism run amok becomes a sterile, isolated, solopsistic, empty narcissism, where the feelings and dignity of other creatures has zero value. Utlimately that could include other people. I wonder if the shrinking circle of that logic ends up as Meism. That seems like the definition of hell. I prefer a world of other beings that can delight, surprise, and teach me expressly because they are different from me, yet we share a common existence.
Enough of my self-published internet philosophizing. To bring it all all back to GDP, we could have a glorious world and a massive economic boon by taking the actions needed to prevent climate catastrophe. I wish the big business interests would pull their heads out of their asses long enough to see that opportunity. The money we spend on military budgets would probably be enough to pull it off.