One of them is the cost of everything being in the wrong place. Humans have built farms, dams, ski resorts, cities, and all kinds of other things based on the current weather. If the Earth warms up, all of these things will be reduced in effectiveness.
What about the cost of preventing any changes of climate.
Not that I believe humans are capable to control global climate. This is usual communist megalomania.
This is so silly because climate has been changing since the beginning of Earth.