Associated Press: Actress Sigourney Weaver is making her second trip to Congress in as many weeks, urging lawmakers to help oceans by reducing carbon dioxide emissions. She made her pitch Thursday as a new report found that ocean chemistry is changing because more carbon is being absorbed into the seas from the atmosphere. The resulting increased acidity of the oceans poses a serious threat to shellfish and other marine life. Weaver urged senators at a hearing to pass climate change legislation …