Or in my paraphrase, love 'em (options 2 and 3) or leave 'em (option 1).
- Abandon our coastal cities and retreat inland
- Stay put and try to adapt to the menacing new conditions
- Stop burning planet-warming fossil fuels as fast as possible
Why should we care about coastal cities? Remember Willie Sutton's response to why he robbed banks? "Because that's where the money is". Well, we should care about coastal cities because that's where the people are, or an awful lot of them in any case.
The ability to trade was a major growth stimulant for early cities whentrade flowed primarily over the water. This correlation between big cities and location on a coast, meaning that today we have coastal mega-cities, with many millions of population.
Now that we are observing rising sea levels of an average of 3 mm/year since 1993 (see IPCC 2007 Working Group report here) and tropical storms and hurricanes of longer duration and greater intensity (see IPCC 2007 Working Group report here), the risk to these cities is escalating. If we hit a tipping point where the Greenland icepack melts, the seas would rise a whopping 7 meters.
Economics is what seems to get people's attention, and Florida includes an interesting table about the potential for financial losses in huge coastal cities. There is huge vulnerability today and even more by 2070.
Options 2 and 3 above are not cheap. Doing nothing may be more expensive.
This whole discussion brings into sharp focus a major frustration of mine. There's a common slogan "Save the Planet". I don't agree with that slogan. The planet will do just fine no matter what we do about climate change, including nothing. What we need to think about is "Save our Civilization". That's 'all' that's at risk with climate change.
 Richard Florida is an urban studies theorist at the Rotman School of Management at University of Toronto and head of the Martin Prosperity Institute