Q. A few years ago you conducted a poll of ecologists to identify the top 10 causes of environmental problems. Would you comment on your original list in the context of today's world?

A. Listing the top 10 sources of environmental problems is one way to put them in perspective. The original list included seven that were somewhat interchangeable as to how they should be ranked. One, two, and three were the same in almost everyone's list, although not always in the same order. Following is the original ranking of environmental problems, in order of increasing concern, with my current comments.