For one thing, "rising sea levels" is often used as a symbol, representing all the varied consequences of global warming, the most depressing of which may be global ecological turmoil, so you might consider taking it less literally.
For another, rising see levels are going to wipe some island countries off the map and displace a quarter of the Bangladeshi population, among other things. It doesn't seem unreasonable to be dismayed by the social unrest that will surely accompany those events.