Gr 6-10 These hi/lo books provide basic introductions to environmental problems related to the Earth's atmosphere. Cefrey explains the growing hole in the ozone layer, causes of ozone depletion, harmful effects of UV rays, and potential solutions. She urges readers to take steps to reduce the dangers. Photos and diagrams reinforce the message. If libraries own Alex Edmonds's The Ozone Hole (Copper Beech, 1997) or Sally Morgan's The Ozone Hole (Watts, 1999), they may not need Cefrey's work unless demand by report writers is high. Friedman tackles issues of global warming, explaining the increase in greenhouse gases and stressing the impact on weather patterns, human settlement, and plant and animal life. She also suggests ways in which readers can have an impact. Because of the scope of this book, the explanations are sometimes oversimplified. One of the diagrams is almost identical to one that appears on the E.P.A. site, which is included in the resource list, but is not attributed. Several books in the list for further reading contain minimal information on the topic. However, Laurence Pringle's Global Warming (SeaStar, 2001) is included, and is a more thorough, attractive, and balanced introduction to the subject. -Kathy Piehl, Minnesota State University, Mankato Copyright 2002 Cahners Business Information.