WASHINGTON (Reuters) - President Barack Obama’s top adviser on energy and climate change, Heather Zichal, plans to step down in the next few weeks after five years at the White House, senior administration officials said on Monday.

Zichal, 37, has advised Obama since his 2008 presidential campaign and helped shape the administration’s policies to curb greenhouse gas emissions blamed for contributing to global warming.

Zichal was the architect of the president’s plan, announced in June, to cut carbon emissions from U.S. power plants, reviving his climate agenda after a planned “cap and trade” system was thwarted by Congress during his first term.

Zichal plans to move to a non-government job. She had other opportunities within the administration but decided the time was right to move on, officials said.

A replacement has not been named.

“Heather is one of the president’s most trusted policy advisers. The president values her expertise and counsel and is grateful for her service,” White House chief of staff Denis McDonough said in a statement emailed to Reuters.

Dan Utech, a deputy director for energy and climate change at the White House and one-time adviser to former Energy Secretary Steven Chu, could be tapped to replace Zichal.

An Iowa native, Zichal is one of only a handful of advisers from Obama’s 2008 campaign still working at the White House. Other big names such as communications gurus David Axelrod and David Plouffe left for the private sector much earlier.

The first-term heads of the Environmental Protection Agency, Department of the Interior and Department of Energy have also stepped down and been replaced.

Zichal started thinking about leaving the White House after the 2012 election but waited to help usher through Obama’s new climate initiatives in June. Obama raised the hopes of environmentalists with his reference to climate change in his January inaugural address.

The EPA is now taking the lead on implementing that agenda, with emissions standards for new power plants unveiled in September and those for existing plants due in 2014.

But officials said the White House would continue to be deeply involved in climate and energy policy.

“We will continue to make important progress in reducing carbon pollution to help keep our air and water clean and protect our kids, helping communities prepare for a changing climate and leading international efforts to address climate change,” McDonough said.

LEGACY, BALANCING ACT

Zichal’s job mixes outreach with environmentalists, industry and lawmakers on Capitol Hill. She helped implement policy to double renewable energy generation in Obama’s first term and oversaw the administration’s response to the 2010 Gulf of Mexico oil spill.

Zichal worked with car makers and fossil fuel producers to try to balance Obama’s ambition to curb pollution without putting an undue burden on the economy. That led to a 2009 deal to boost fuel efficiency on new cars that was backed by the auto industry.

Obama’s plan to cut pollution from coal-fired power plants, meanwhile, is likely to face years of court challenges.

An administration decision on whether to approve or reject TransCanada’s Keystone XL oil pipeline from Canada looms as the next defining moment for Obama’s climate legacy.

The president surprised listeners to the June speech unveiling his new climate policies by signaling he would block construction of the pipeline if it significantly exacerbated the problem of carbon pollution.

One senior administration official told Reuters on Monday Obama should be judged by whether he keeps his promises reducing greenhouse gas pollution rather than on his decision on any one particular issue. The decision on Keystone, technically being handled by the State Department, could still be months away.