text: So what does available evidence show? And where do environmentalists begin to get their numbers? Well U.S. News and World Report (12/13/93) explains that while the figure of 40 million acres per year "has taken on a life of its own," it is being "cited and recited without reference to its origins. Yet almost half the estimated total comes from a very rough estimate made by a Brazilian scientist who used sensors on a U.S. weather satellite to count the number of fires burning in the Amazon at one time in 1988 . He estimated the size of each, The resulting number was into the widely cited report by the World Resources Institute that helped fuel the alarm over vanishing tropical forests; was cited by Gore and other administration officials last spring in announcing support for the Biodiversity Treaty.