In the Spring edition of the Journal of the American Planning Association, four researchers from the United Kingdom published an article which essentially concludes, based on computer models of three different cities with three different levels of density, hyper-dense, moderately dense, and sprawling, that the compactness of the urban form has little impact on sustainability.
I certainly don’t have the academic credentials to critique the study, but it certainly seems to fly in the face of pure logic. On the other hand, when have human beings been accused of logical thinking?
Take a look at the article here.
Here's a brief newspaper account.