It's going to be a long Hurricane Season

Four Atlantic weather systems -- Arlene, Bret, Cindy and Dennis -- reached Tropical Storm status by July 5, the earliest for so many named storms in recorded history. Only three major hurricanes (Category 3 or higher) have hit the U.S. coast in July in the past 100 years.

Dennis gains strength

As of 11:00 a.m. ET, Dennis' maximum sustained winds increased to 150 mph, making it a very dangerous Category 4 major hurricane. The hurricane's pressure dropped sharply earlier in the morning, prompting the intensification. Remember, a Category 5 hurricane has sustained winds greater then 155 mph so Dennis is indeed a very strong Category 4. Hurricane Dennis made a brief landfall near Cabo Cruz, Cuba on Thursday evening. The eye will make a second landfall on the south-central coast of Cuba this afternoon, move across western Cuba and finally emerge into the Gulf early Saturday.

One of the first impacts of global warming is more and bigger hurricanes.

However, hurricane intensity and rainfall have been increasing consistently. For instance, the total precipitation from hurricanes hitting the US rose by about 7 per cent over the course of the 20th century. This is because the sea-surface temperature and atmospheric moisture content have been increasing as the world warms, and both provide the energy to fuel hurricanes, writes Trenberth.

Large hurricanes in the Gulf of Mexico impact the entire country. Much of the domestic oil supply comes from the Gulf of Mexico. Large hurricanes at the least result in offshore oil platforms being shut down during the storm but often result in damage resulting in long shutdowns and a loss of domestic oil and gas. How many more major hurricanes in Florida before the state is simply abandoned? A major hurricane making direct hit on New Orleans will result in the destruction of that city and it will not be rebuilt. Think of the economic impact. Global warming is here, hang on.