The encyclical letter Laudato Si is available here on the Vatican website. Here, Pope Francis criticizes cities, not as entities, but as unplanned and unhealthy locations for any person:
44. Nowadays, for example, we are conscious of the disproportionate and unruly growth of many cities, which have become unhealthy to live in, not only because of pollution caused by toxic emissions but also as a result of urban chaos, poor transportation, and visual pollution and noise. Many cities are huge, inefficient structures, excessively wasteful of energy and water. Neighborhoods, even those recently built, are congested, chaotic and lacking in sufficient green space. We were not meant to be inundated by cement, asphalt, glass and metal, and deprived of physical contact with nature.
A friend with relatives in Houston has tart criticism for an urban/suburban sprawl that takes “ninety minutes to cross” by car. In my recent job search, I was comparing two cities: a tightly-planned Portland in Oregon with a wide-open counter-approach of that Texas locale. In the Third World, I suspect, the issues are more serious. People come to cities looking for survival, and find instead this “urban chaos.” Not just undesirable conditions far away from gated and protected enclaves, but unhealthy ones.
Personally, I love the excitement of cities. People have to live somewhere. And cities, well-planned, need not be wasteful and dangerous wildernesses of broken glass, crumbling stone, and non-recycled trash.