Long-term real-estate play: buy land near urban areas that will be soon submerged (100 year time frame) and near the "new" coast.
What I do believe is that a major UN climate conference is starting today in Doha and that their PR people yet again managed to sell the idea of disaster to the newspapers.
Sell a piece of land a few kilometres in for a lot of money, citing it's major benefit as future beachfront property (put ads in local paper, etc). If anyone actually decides to buy it at that price, cover your losses and donate the rest to WWF or Charity:Water.