Of course, this argument all comes down to alternative uses of land vs. golf course construction and maintenance. Presumably, and without reading his statements in context, the gentleman from the Sierra Club was referring to golf vs. some sort of preserved "state of nature", in which case he is inarguably correct. At the very least, there would be some erosion from construction, some pollution from fertilizers and pesticides and mowers, some reduction of wildlife, trees, etc. It would be silly to assert the contrary, and that would apply to NGLA, Cypress, or the newest courses built today under the strictest environmental regulation.
On the other hand, we here prefer to contrast golf with housing developments and apartment complexes and shopping malls, because that suits our purposes as demented OCD sufferers. Again inarguably, golf would be preferable to any of THOSE uses.
As is usually the case, the truth is somewhere in between the extremes, and has to be determined case-by-case. The reality is that land gets developed, and a golf course is more environmentally friendly that a heck of a lot of other possibilities. However, we would be equally silly here as advocates of the game to ignore some problems.
IMHO, in the future the big issue facing golf, especially public golf, will NOT be the environmental problems. It will be the use of so much land for so few people. That is going to be a real challenge for the game's growth.