Pieces of ice fall from the front of Argentina's Perito Moreno glacier near the city of El Calafate, in the Patagonian province of Santa Cruz, in this file photo. REUTERS/MARCOS BRINDICCI Thirty years ago, on June 10 and 11 of 1986, the U.S. Senate Committee on the Environment and Public Works commenced two days of hearings, convened by Sen. John H. Chafee, R-Rhode Island, on the subject of "Ozone Depletion, the Greenhouse Effect, and Climate Change."