Tropical Storm Rita is the 17th tropical storm of the Atlantic hurricane season and comes on the heels of Hurricane Katrina, one of the most destructive ever to strike the United States.  Some climatologists believe there is a connection between the growing number of these violent storms and global warming. VOA's Melinda Smith has more on the latest scientific reports to back up that claim.

Robert Chil, an employee at the Sports Authority in Miami, boards up the store's windows Monday ahead of tropical storm Rita

Residents and tourists were ordered to get out of the path of Rita, as she headed toward the Florida Keys.  Emergency management officials warned people to take this storm seriously, especially in the light of devastation caused by Hurricane Katrina.

A recent study released in the journal Science has raised the issue once again of whether global warming is responsible for the increase in these violent storms. 

Climatologist Peter Webster provided these facts: "The total number of storms that are reaching Category 4 and 5, and the number of days that they are staying at Category 4 and 5 is increasing substantially."

Peter Webster

Thirty-five years ago, major hurricanes made up about one-sixth of all tropical storms.  In recent years, that percentage has risen to one-third.  During that same time, water surface temperatures around the world have also grown warmer.  The warmer water evaporates at a quicker rate, and once it rises into the atmosphere, the condensation releases energy that forms the storm. 

An increase of one degree Fahrenheit may not sound like much, but climatologist Stephen Schneider says it is significant:

"We'll see more heat waves.  We're going to see reduced snow pack, longer dry season and probably more wildfires at the end of the dry season." said the Stanford University professor.

Stephen Schneider

In the United States, the Gulf and Atlantic coasts are not the only shorelines to worry about.  In California, for example, scientists say the pattern of rising sea levels could mean as much as 1770 kilometers of Pacific coastline submerged and water supplies for millions of residents potentially threatened.

Professor Schneider says the warmer water would evaporate more quickly in reservoirs creating water shortages: "The cities are going to want it.  The farmers are going to want it, and the people who protect nature are going to want it, and soon we're going to have a clash."

The United States has refused to sign the Kyoto Protocol, an international agreement designed to curb global warming by requiring industrialized nations to lower their greenhouse emissions.  President George W. Bush says the protocol exempts largely populated China, India and Brazil from compliance, and would also cause serious harm to the U.S. economy.

Not every scientist agrees with the study linking the increase in hurricanes to global warming.  Some say the study is based on faulty data, and that methods for measuring weather patterns are not uniform worldwide. 

But those who agree with the report say, while no one knows for sure how many hurricanes will be spawned in the future, a greater number of those storms will be packing a deadly punch.