Greenwire: A Senate proposal setting up a cap-and-trade program to curtail greenhouse gas emissions likely will be offered on the floor later this summer as an amendment to a smaller, energy-only approach, Sen. Chuck Schumer (D-N.Y.) said today. Appearing on MSNBC, Schumer said he expects Senate Democratic leaders to use legislation from Energy and Natural Resources Chairman Jeff Bingaman (D-N.M.) as the base proposal to launch the floor debate. “It’s going to be a good strong energy bill, and I …