The lead authors of Senate climate legislation pushed back today against a request from Finance Chairman Max Baucus (D-Mont.), who wants to water down the bill's 2020 target for greenhouse gas emissions. Baucus today said he has "serious reservations" about the current Senate bill (S. 1733), which seeks to curb U.S. emissions 20 percent below 2005 levels by 2020. But sponsors of the Senate bill say the recent economic downturn has already driven down domestic emissions and makes their goal that much more achievable.