... So, honest question. What's wrong with global warming?
Air warms up - seas warm up - ice melts - high volume of fresh water enters the northern oceans - sea levels rise - ocean currents such as the Gulf Stream/Atlantic Conveyor stop delivering their benefits northwards - northern latitudes such as Europe and Western N America cool down, while southern latitudes get drier and hotter, plus many other induced changes to flora and fauna, including our weather systems and our agriculture - on all of which we are dependent. Current civilisation has to adjust to this rapidly or follow the dinosaurs and mammoths into extinction, whilst in the midst of a population explosion demanding more food and water.
Does that equation look comfortable to you, whether you happen to live on a beach front or not?
Anyway, where does it say that life was so much more abundant before? And just when was that? Certainly a good deal has already been killed off directly or indirectly by human activity. But life is not going to exist in either hot or cold deserts in any volume. So where would it find a home if your logic somehow works?
What's wrong? Humans have adjusted quite well to a wide range of climate in the past, in limited numbers. But only with the aid of resources and within limitations. So a diminishing supply of those is not going to support today's 7 Billion+ humans or more in extreme conditions.
Or maybe you have an answer to your own 'honest question'. No joking!
