Barrons AP Environmental Science

Source: U.S. Environmental Protection Agency (EPA)
Figure 11.9 Average global sea surface temperature Worldwide,
Category 4 or 5 hurricanes have risen from 20% of all hurricanes in the
1970s to 35% of all hurricanes in the 1990s. Computer simulations and
projections for the 21st century show that the number of Category 1, 2, and
3 hurricanes in the Atlantic will diminish while, during the same period of
time, the number of Category 4 and 5 hurricanes will increase dramatically.