This photo I took while flying out of Istanbul yesterday morning shows the vast expanse of the city. The Sea of Marmara and a sliver of the Bosphorus are visible in the background. The land below is Europe, while the hills in the background, likewise smothered with concrete and asphalt, are Asia.
A pet peeve of mine is the seemingly endless growth, sprawl, of cities that are already way too big. In many developing countries like Turkey land development is not as well planned and controlled as it may be in more developed countries. As a result, such development robs the countries of their naturalness and irreversibly destroys wildlife habitats. I have touched upon this subject before.
One idea that I have been running into lately is that densely populated, but compact high-rise cities are actually good for the environment, because they free up land elsewhere that could be restored. (For example, see this interview with Jesse Ausubel; full text requires subscription to the New Scientist.)
One problem with this approach is that the city dwellers can't be expected to spend their entire lives in vertical habitats; they also need to go on vacation in more horizontal places. And this means highways, airports, hotels and houses will continue to be built elsewhere. At the end, there is no net gain in land.
The population of Istanbul was about 800,000 in 1927; by 2000 it had reached a staggering 10 million. There will be no solution to the problem of land destruction until this maddening population growth of humanity, and the religious fundamentalism that fuels it, are curbed and controlled.