I don’t see any issues as long as you carted away all of the material that you excavated. You could even build up the land to make it taller and harder to flood.

But unless you did it without burning any fossil fuels, then the additional greenhouse gases would cause more ice to melt. And you’d run the risk of fucking up ocean currents and weather systems which, again, could worsen global heating…

On second thoughts, maybe hold off on that plan for now