To prove your point you will need to find a time when temperatures were higher then now, and supported a higher level of human life. Good luck with that! Otherwise your point that "A warmer wetter world might support more people," is utterly speculation.
Oh, well I dont need the fossil record for that. There's more people alive today than in the past so global warming is supporting more people. The population increased and civilization was born during a period of global warming and we're riding that wave. The proof was right before you and will be there tomorrow with an even warmer world and a larger human population.
But my point was life flourished with much warmer temperatures. I dont accept your logic that I need to show a warmer world from the past with a larger human population given the population has never been this big, all I need to show is how life responded to warmer worlds in the past.
I doubt our current population could have existed 4 centuries ago in the little ice age. I'm less worried about CO2 than a lengthy cold snap.
The flaw in your argument is that this is going from a cold climate to a temperate climate, rather than from a temperate climate to a hot one. Humans favor a narrow climate range, and we are already on the high end of it.
I dont know how you're defining hot, temperate and cold so lets deal with actual temperatures. I've seen estimates Greenland warmed up to 18F within a few decades. You argued the current rise in temperature is unprecedented given the time frame. Now you're claiming a small rise in temperature constitutes a 'hot' world, so how would you describe past worlds when the average temp was 15-30F warmer than today?
Those who can will, those who can't will die presumably? Plus mass migrations historically speaking don't tend to be peaceful affairs. For example the end of Roman empire can be linked to climatic changes (in this case less stable and cooler conditions) which caused mass migration and crop failures. However if you look at the chart above, they weren't facing anything as rapidly changing as we are facing.
Less stable, cooler conditions... or more stable, warmer conditions. Those who will, can. Those who wont will adapt. I've lived in below freezing cold and Phoenix, I worked in an open warehouse that would hit 125F, thats a helluva range.
Could it not be said Biden was caught out by the lie too which led to him supporting the Iraq War?
No, he was one of the liars and I'll bet he knew about the torture program too. Pelosi did, I'm sure Senate Democrats like Biden were well informed about what was going on. Thats how the torturers avoid future legal troubles, they make their crimes bipartisan. Thats one of the reasons why few people got prosecuted except for some low level grunts following orders to 'soften' up Iraqi prisoners.
I know Biden and Clinton were in on the lie because of how they acted. If I was a senator and voted for a war based on a lie I'd be furious and I would enthusiastically bring the liars to justice, not cover for them. I seriously doubt more than a handful of congressional members didn't understand it was a scam, they actually had access to intel. Another clue was how the hawks kept citing foreign intel, what do our people say about that? Never mind, trust our foreign intel

Okay lets discuss your indifference to all the lives being lost to climate change.
Which of these scenarios could save the most lives?
A. An opposition senator decides not to support the Iraq war (deaths from Iraq war estimates range from 151,000 violent deaths to 1,033,000). How many lives would have been saved?
The death toll keeps climbing, Iraq, Libya, Yemen, Syria, Afghanistan, and a few other places. But I wouldn't say I'm indifferent, just skeptical about studies blaming a small bump in temperature for an environmental disaster.
B. The leader of the US provides clear and determined leadership when faced with a global pandemic (deaths from Covid 228,000 and still rising). He does not disband the pandemic task force, does not provide confusing health advise (?inject yourself with bleach), does not feud with state governors, does not downplay the danger of the virus despite knowing its dangers, does not feud with the scientists and health experts advising him (such as trying to discredit them), does not promote medications regardless of their actual benefits (see Hydroxychloroquine) and he does lead by example following recommended precautions for dealing with the pandemic such as social distancing and wearing a mask (rather then frequently doing the opposite). How many lives could have been saved?
Not many, Trump doesn't run the states. I remember him sending a hospital ship and rushing ventilators to NYC and other governors thanked him for helping them out. But he was following the advice of the scientists, they told him and the Democrats and the media to avoid panic buying of PPEs so all of them did as told, they downplayed the virus and they downplayed masks. It wasn't Trump who sent infected people into NY nursing homes.
C. The leader of the US takes a lead in combating climate change (deaths from Climate Change by 2050 estimated to rise to 6,500,000).
Our wars on drugs & terror might be in that ballpark by then, but how many lives will result from global warming?
He invests in sustainable energy, works to find ways to reduce carbon dioxide output (there are many). Maybe tariffs are placed on countries that continue to pollute heavily. He does not call climate change a hoax, he does not ignore reports proving it is happening, even those from his own administration, he does not pull out of the Paris accord, he does not promote fossil fuels, he does not pursue over 100 anti-environment policies and removal of regulations designed to protect the environment, he does not undermine the EPA, and he does not put a climate change deniers in charge of the EPA! How many lives could have been saved?
I suggest you watch Planet of the People about 'sustainable' energy. People are working to find ways of reducing CO2, thats one of the reasons your studies about 2050 are irrelevant. I'll repeat this, Obama and Biden oversaw Arctic drilling, oil sands pipelines and the fracking boom. And now Biden's an environmentalist?
By the way how do you feel about the fact that Trump vetoed a senate bill that Biden supported which wanted to end the US support for the humanitarian catastrophe that is the Saudi led war in Yemen? Doesn't really fit in with your narrative does it!
The war in Yemen and our support for SA began under Obama and Biden as part of their "Arab Spring" plan to topple governments they didn't like. Presidents typically veto challenges to their constitutional powers on principle, but I dont like arming SA.
My final question is more one of curiosity, are you against all wars, or just certain ones?
Self defense justifies war