The general trend in the last 4,000 years is that carbon dioxide and temperature have been moving against each other.
Polar bears did very well in the warmer times. They didn't die out at all; they didn't die out in the last 10,000 years, nor during the previous interglacial, nor the one before that. So, they're just used as a deceitful heartthrob; you know, to pluck your heartstrings because the polar bears might die out.
My view is that climate changes have happened in the last 80 years, that is, the world has got a little bit warmer, although not as warm as it has been in Medieval times, or the Bronze Age.
It's not the case that carbon dioxide drives temperatures. When you leave Ice Ages, it's the other way around: The temperatures go up first, and then carbon dioxide levels go up.
Computer modelling for weather forecasting, and indeed for climate forecasting, has reached its limits.