Unfortunately, this phenomenon has already begun, not in countries around the world, but right here in the United States, where the first massive movement of climate refugees has been that of people away from the Gulf Coast of the United States.
Hurricane Katrina, which made landfall in late August 2005, forced a million people from New Orleans and the small towns on the Mississippi and Louisiana coasts to move inland either in state or to neighboring states, such as Texas and Arkansas. Although nearly all planned to return, almost a year later 375,000 — or a full third of those million evacuees — have yet to return.
Unlike in previous cases, when residents typically left areas threatened by hurricanes and returned when authorities declared it was safe to do so, many of these evacuees are finding new homes. In this respect, the U.S. hurricane season of 2005 was different. Record-high temperatures in the Gulf of Mexico surface waters helped make Hurricane Katrina the most financially destructive hurricane ever to make landfall anywhere. Interestingly, the country to suffer the most damage from a hurricane is also primarily responsible for global warming.
New Orleans' population before Katrina struck was 463,000. Claritas, a private demographic data-gathering and analysis firm, reported that after the hurricane New Orleans' population shrank to 93,000. By January 2006, it had recovered to 174,000. By July 2006, the city still had only 214,000 residents, less than half of its pre-Katrina size.
Similar population declines took place across coastal Louisiana and Mississippi, bringing the total displaced population count, as of July 2006, to 375,000 residents because of destruction from Katrina.
Of these 375,000, we at the Earth Policy Institute estimate that at least 250,000 of them have established homes elsewhere and will not return. They no longer want to face the personal trauma and financial risks associated with rising seas and more destructive storms. These evacuees are now climate refugees.
The Katrina displacement however, is just the first chapter in what may be the beginning of a larger migration from the hurricane-prone coastal regions of the U.S. southeast. A major factor in this reality is the difficulty in getting property insurance. In the wake of the last two hurricane seasons, including the 2004 season when four hurricanes crossed Florida, reconstruction is still ongoing, insurance costs are climbing, and private insurance companies are withdrawing from high-risk coastal areas.
The experience with more destructive storms in recent years is only the beginning. Since 1970, the Earth's average temperature has risen by one degree Fahrenheit, but by 2100 it could rise by up to 10 degrees Fahrenheit (6 degrees Celsius).
We're already seeing the early manifestation of global warming. The longer term risk is that rising temperatures will melt glaciers and polar ice caps, raising sea level and displacing coastal residents worldwide. The flow of climate refugees to date numbers in the thousands, but if we do not quickly reduce CO2 emissions, it could one day number in the millions.
While stabilizing climate and reducing CO2 emissions is not an easy task, we have the technologies, economic instruments, and financial resources to do so, as I outline in Plan B 2.0.
[See TreeHuggerTV's interview with Mr. Brown here. -Ed.]