Senator Lindsey Graham may have bailed on the effort, but Senators John Kerry and Joe Lieberman unveiled their climate-change and energy bill on Wednesday anyway. If passed, the bill would seek to reduce carbon emissions by 17 percent below 2005 levels by 2020 and 80 percent below 2005 levels by 2050. The bill would implement a cap-and-trade system by 2025, though it’s unclear how carbon allowances will be distributed to polluters. It would also place a moratorium on drilling in the Gulf of Mexico until the investigation into the current oil spill is completed.