This paper reviews recent studies and particularly the effects of Climate Change in the North Tropical Atlantic by studying atmospheric conditions that prevailed in 2005 ; Coral Bleaching HotSpot and Hurricane Katrina.

In the aim to better understand and estimate the impact of the physical phenomenon, i.e. Thermal Oceanic HotSpot (TOHS), isotopic studies of δ18O and δ13C on marine animals from Guadeloupe (French Caribbean Island) were carried out.

Recorded measures show Sea Surface Temperature (SST) up to 35°C in August which is much higher than data recorded by NOAA satellites 32°C.

After having reviewed the process that led to the creation of Hurricane Katrina which hit New Orleans in August 29, 2005, it will be shown that the climatic conditions in the Caribbean from August to October 2005 have influenced Katrina evolution.

This TOHS is a combined effect of various phenomenon which represent an additional factor to estimate future climate changes.