The Standard Global Warming argument is that warm weather melts glaciers, causing sea levels to rise, causing coastal erosion. You have just argued that Global Warming causes increased glaciation, and dropping sea levels.
It's all a bunch of hooey.
Oddly enough I've heard environaziswackos make that very argument. The warming causes increased evaporation, increased evaporation increases precipitaion (in part as snow), increased cloud cover reduces melting, snow builds up, glaciers form, world ends...
Warmer temperatures increase melting of mountain glaciers, increase ocean heat content, and cause ocean water to expand. Largely as a result of these effects, global sea level has risen 4 to 10 inches (10-25 cm) over the past 100 years. With additional warming, sea level is projected to rise from half a foot to 3 feet (15-92 cm) more during the next 100 years. On average, 50 to 100 feet (15-30 meters) of beach are lost for every foot (0.3 meters) of sea-level rise. Local land subsidence (sinking) and/or uplift due to geologic forces and coastal development will also affect the rate of coastal land loss.
Hotspot Selection Criteria: The sea-level rise (SLR) data were confirmed by published journal articles. We did not include places where there were tide gauge records of a rising sea level but no information about land inundation consequences (e.g., Buenos Aires, where the shoreline is raised/hardened and thus protected from inundation); places where there was evidence of land erosion but no SLR records (e.g., the island of Geneva and other Caribbean islands); and places where subsidence or other factors (e.g., changes in river sediment deposition) were clearly the dominating influence on land erosion (e.g., New Orleans and Victoria, Egypt). Although the inundation records for the South Pacific islands are based on anecdotal evidence from local residents, we included them because these accounts are often the best and only evidence available in these very vulnerable small island nations.