What the heck is "humanly made"? Harvey's problem is that he does not see the creation of cities, suburbs, farms as the results of the capitalist system. The central preoccupation of Marx was with the absolutely devastating effect of the SEPARATION between city and countryside, which seems to matter little to urbanists like David Harvey and William Cronin. The gist of the disagreement between Harvey and Foster is over this precise question. To talk about the "ecology" of NY, Chicago, etc. as Harvey and Cronin do is to strip the word of all meaning. In his entire book, Harvey does not address this central contradiction ONCE. This is its greatest failing. It means that questions such as the exhaustion of the soil, misuse of water resources (watering lawns in Arizona), waste disposal do not get addressed. These are the things that are killing us. Fertilizer and pesticide runoff into rivers and lakes has disastrous consequences for marine life and causes cancer and are of ZERO concern to Harvey who views urban life in the breathless tones of the narrator of a World's Fair travelogue from the 1930s. Such tall buildings. Gosh! And indoor plumbing!
The Communist Manifesto puts forward the demand:
"Combination of agriculture with manufacturing industries; gradual abolition of all the distinction between town and country by a more equable distribution of the populace over the country."
Louis Proyect
(http://www.panix.com/~lnp3/marxism.html)