Siberia, Canada and Skandinavia are fine for very slow-growing pine trees, not staple food stocks. Even with defrosted soils as there is simply not enough sun.

As for evaporation, the big problem is that it also comes down. More and harder. The million-dollar question is only where and with how much damage.

ps 1. With more water evaporation...why would "The CO2 share in the atmosphere increase"?

ps 2 religions and dogmas I like to leave to the pious. It makes them feel happy and secure. As long as it doesn't affect my life too much it's fine by me.

ps. There is a new field emerging called geo-engineering, so I'm not so sure man cannot and will not (try) to seriously influence the earth's climate by design. Or already have unknowingly by burning at great speed all types of fossil fuels for the last 200 years.