On climate and energy matters, no one had the president's ear more than Carol Browner, for whom a special White House office was formed to lead the push for a wholesale overhaul of energy policy. Denigrated by the right and celebrated by the left, Obama's climate czar—who announced her resignation late Monday—ultimately failed in her central mission: shepherding legislation that addressed the threat of global warming. Political observers and environmental advocates view her departure as a sign that climate may have been banished to the back of Obama's domestic agenda once and for all. Some worry that Browner's resignation could also spell the end for the White House Office of Energy and Climate Change Policy; and they are reading into the timing of the move, just a day before Obama's State of the Union and at a time when the administration has veered noticeably to the center.
"In politics there are no coincidences, especially during the State of the Union news cycle," remarks a House Democratic aide who works closely on energy issues. "It's hard to ignore this as anything other than a message of some kind."
EDIT
Yet her departure comes as many have given up any hope of passing comprehensive climate legislation during the remainder of Obama's term. With the House under Republican control, a stalemate on the issue is virtually guaranteed. And Browner, like other veterans of the Clinton administration, knows what it's like to deal with a divided Congress. After the Republican takeover of the House in 1995, Browner and the EPA were top targets for investigation and allegations of wrongdoing. Recently, at least one Republican House committee chairman listed grilling Browner as a top priority. Some Democratic insiders speculate that Browner may have departed in the interest of avoiding a repeat of the Clinton-era inquisitions at a time when her efforts aren't likely to pay off in any major way.
Others point out that the staff change comes amid personnel reshuffling at the White House, including most recently the appointment of former JPMorgan executive Bill Daley as Obama's new chief of staff, a move that riled progressives but pleased many business interests. That, along with the administration's more business-friendly tone following the midterms, has caused concern among some environmentalists that Browner was sacrificed in effort to bolster that centrist appearance.
EDIT
http://motherjones.com/politics/2011/01/carol-browner-resignation-climate-change