STEINBECK'S novel, The Grapes of Wrath, told of a family forced from their farm in Oklahoma in the 1930s by a prolonged drought, and the subsequent loss of top soil that resulted in the Dust Bowl. These migrants were called 'Okies' and it is now likely that another mass movement of American people could be on the cards.

This time, however, these new 'Okies' will be motivated by too much water, all of it salty, as Florida suffers from climate change. Another difference is they're unlikely to be stuffed into old Ford cars with mattresses on the roof as now they'll be in four wheeled drive, petrol-gulping, CO2-spewing monsters that are not unrelated to the unfolding disaster.

Florida as we know it won't exist by the end of the century, as it faces problems that it can't do much about. It's not high enough, it's made of limestone and the sea level is rising.

It's a long narrow peninsula surrounded by warm seas on three sides, and is larger than England and Wales but with very few hills. For most of it the highest points are below 300 feet, (think lower than Shipley market place), and the 4,000 square miles of the Everglades swamps in the south are close to sea level.

The key problem, though, is the underlying rock type – it's a highly permeable and porous limestone that allows sea water to flood in and bubble up through the drains and into low lying properties following spring and autumn high tides. It's not like Holland, where the water can be kept out with a dyke – here it comes in underneath.

In the Miami region alone there's over £100 billion worth of coastal property, some 300,000 homes, generally less than three feet above normal high tide. This means frequent local flooding, contaminated drinking water, problems of disposing of sewage and waste, as well as possible threats to an ageing nuclear power station.

And then there's the rising sea level. Not only will the extra water come from melting ice in Greenland and the West Antarctic but as the seas warm the water expands, by two millimetres a year, and it's expected it will all lead to a rise of at least two feet over the next fifty years. Add to this spring tides, normal storm surges, plus hurricane enhanced ones, and the future's wet.

Miami's residents are just making the problem worse by trying to build their way out of the problem, with pumps and walls. They are raising street levels, redesigning ground floors, and installing hundreds of expensive pumps.

These all mean more CO2, more warming and more water, so inevitably less Florida.