The Day: Adapting to rising sea levels, more frequent and intense rainstorms, warmer temperatures and other effects of climate change would be costly, but inaction would be costlier. That was the point made by the panelists for “Staying Dry and Paying for It,” a symposium Tuesday at the Avery Point campus of the University of Connecticut on the costs of coastal living in a changing climate. “It’s pretty hard to armor the coast” against sea levels rising an average of 2.5 mm per year, …