Only half the world's original forest cover now remains. And WWF estimates that between 1970 and 1995, the world lost about 30 percent of its natural wealth. The decline and disappearance of frog populations worldwide remains a mystery, despite efforts by hundreds of scientists to determine the causes. During the past six months, press interviews with research scientists, and published studies, have shed a bit of light on both problems though true consensus has not yet emerged on either one. No one is even sure whether the two problems are connected, though new evidence indicates they are.
Some scientists still doubt that frogs are actually disappearing worldwide.
They prefer to believe that the simultaneous declines and disappearances of frog populations in North and South America, Europe, and Australia reported since 1980 are nothing more than the normal ups and downs of any wild population. There are roughly 5000 species of amphibians worldwide. Global warming and accompanying droughts may contribute because frogs develop from eggs that thrive in water. The artificial stocking of streams with trout and bass plays a role, too. Laboratory experiments have shown beyond doubt that ultraviolet light from the sun can interfere with the development of frogs' eggs.