WASHINGTON - The Smithsonian Institution toned down an exhibit on climate change in the Arctic for fear of angering Congress and the Bush administration, says a former administrator at the museum. Among other things, the script, or official text, of last year's exhibit was rewritten to minimize and inject more uncertainty into the relationship between global warming and humans, said Robert Sullivan, who was associate director in charge of exhibitions at the Smithsonian's National Museum of Natural History. Also, officials omitted scientists' interpretation of some research and let visitors draw their own conclusions from the data, he said. In addition,...