http://www.reuters.com/article/idUSTRE6AO21Q20101125
NOAA tide gauges located on islands show an average rise rate of 1.22 mm per year, or less than five inches per century.
http://tidesandcurrents.noaa.gov/sltrends/sltrends_states.shtml?region=wm
I doubt that even the Aztecs were superstitious enough to believe that they had the power to change the sea through sacrifice. 21st century man may be the most superstitious group to ever occupy the planet.
Why is Grenada involved?
Most of the island is hundreds of feet above sea level. Even a Hansenesque rise in sea levels would do no more than flood a few beach huts.