"has ever been" is a very long time
well beyond the science
Well, ever in
human terms. We need to focus on the planet and the biosphere conditions that have supported our growth and development.
There are two key periods for that. The first is 3 million years. It's only been that long since the American continents met up at Panama and changed ocean circulation so that equatorial waters no longer act as an unbroken band of warm water around the centre of the globe and have, since then, diverted warm waters northward through the Gulf Stream. The second is the 10000 years of the Holocene. The only reason we have been able to create our agriculture based civilisations is that we have predictable, reliable seasons suited to the cultivation of annual grasses.
Any references to climate conditions before 3 million years ago can only give us very,
very general guidance about our own circumstances. Just the physics really. Such and such a CO2 concentration maintained for
x years is likely to result in
y temperature. That temperature likely means sea levels
z metres higher or lower than now.
The substantial ice sitting at the poles is the air conditioning unit driving our predictable seasonal conditions. Hadley cells, Rossby waves, jet streams, trade winds are just a few of the major air circulation processes that bring rainy, windy, dry conditions to various places at predictable times. Reducing the ice reduces the temperature differentials between the equator and the North Pole in particular. Which slows down Rossby waves - whoops! Suddenly we get rain that stays for days or weeks and washes our crops away instead of watering them. Or we get dry periods that stay in place for weeks at a time and dessicate our soils and fry our crops instead of warming the soil and maturing the crop.
You may not like ice or snow. I certainly don't. I live in a city that has never recorded a temperature below 0C. But I'm grateful for it. With ice at the poles and the mountaintop glaciers, I know that the weather systems that have allowed human civilisation to grow and flourish will keep on doing so.
If you don't like ice, or even the idea of it, think about it the way we
don't think about sewage systems in cities. We don't want ever to go there, let alone work there, but we're very grateful for its contribution to a healthier place to live. And we want it to always be there. Out of sight, well maintained, doing its job, making our lives safer and better.