Golf courses can also be
beneficial to the
environment - in areas where they do not use up scarce ressources like water or land.
If we take Germany as an example, golf courses are usually built on spaces used for agricultural monocultures. To get a permit to build a course, the whole are has to be re-naturalized, a minimum of 1/10 of the area turned into a nature reserve, which is also closed to golfers.
When it comes to fertilizer and pesticides, any green keeper using more than absolutely necessary not only hurts the environment but the quality of the course as well.
Besides - if you see perfect, green greens on tv, on a course that is located in a hot, dry area, the chances are that it has been dyed green. (Yes, there is a special paint to dye grass a nice shade of green when it is brown...)
Now - for the real downside of golf :
it is addictive...