This latest in a barrage of environmental overviews by big names takes a lowest-common-denominator approach, chatting up readers in discursive if not patronizing prose that spends much time assessing concepts such as Gaia and countering implied arguments that might be made by people who are either simple-minded or misinformed. Those who respond favorably to this treatment, though, might take to the totally nontechnical profiles of the major suspects- -global warming, ozone depletion, mounting trash, air and water pollution--because science-fiction institutions Asimov and Pohl sum up the problems clearly and include some jolting details about their causes and effects. Still the topics have been covered again and again in recent popular books and newspaper articles. What Asimov and Pohl promise to add here are suggestions for how catastrophe can be avoided and how political means can effectuate solutions--but these sections prove particularly weak. The authors don't come through with new visions or specific programs, and their political section combines the usual suggestions (write letters to public officials, etc.) with sketchy advice on starting an organization (pros and cons of having a constitution) and getting into politics through helping candidates, getting on political- party municipal and county committees, and getting out the vote on election day. Again, most of this is commonplace in manuals for grass-roots activists and unrelated here to the environmental issues they're supposed to implement. Just because the entire book is so basic, however, some libraries may find it handy.