Washington Post: There have been hotter days on Capitol Hill, but few where the heat itself became a kind of congressional exhibit. It was 98 degrees on June 23, 1988, and the warmth leaked in through the three big windows in Dirksen 366, overpowered the air conditioner, and left the crowd sweating and in shirt sleeves. James E. Hansen, a NASA scientist, was testifying before the Senate Energy and Natural Resources Committee. He was planning to say something radical: Global warming was real, it was a …