The article itself did not focus on making predictions on global warming. The title, while a bit sensationalised, is not wholly inaccurate and was probably picked by the editor not the writer. The other two claims that I could find were about the potential damage of a six-foot sea level rise, which was probably accurate even if it didn't list out the likelihood of such a rise, and the article by the Union of Concerned Scientists which made a claim about the likelihood of increased flooding that seemed reasonable to me.
It is not trying to make the case for/against global warming to a non-scientific audience. It is trying to make the case against bullish development in S. Florida to investors who subscribe to Bloomberg. The point is basically, "Even if these guys don't end up under the ocean in 50 years, they're still going to have to pay more in taxes and water rates just to keep the city afloat"