Are there environmental consequences for removing all ice from polar regions?

Are there environmental consequences (e.g. global warming, rising sea levels) if I transform all the ice in the polar regions into ice-free terrain (e.g. forest, grassland, plains)? I am planning to expand my empire by colonizing the polar regions. I don't want to cause the sea levels to rise when I remove all the ice.

A few years ago, I planned to fill all ocean tiles and terra-format both polar region. Polar region was nearly 75% as prairies and ocean was filled maybe at 10-20% and became prairies too.
I can`t remember was version was but it was around 2010ish
The sea level never risen.