Even before George W. Bush can settle into his new house in Dallas, his legacy on the environment is being dismantled by his replacement in the White House.
In less than two months, President Obama has put on hold Bush's plans for power-plant pollution, offshore oil drilling, nuclear waste storage and endangered species.
The Obama team has rolled out policies Bush officials delayed, such as requiring higher energy efficiency from appliances.
Such moves have significant impacts and not just on the environment. They could affect electric bills, gas prices and the time it takes to build highways, dams and bridges.
For now, the decisions are winning plaudits from green groups — "swift and strong leadership," the Natural Resources Defense Council gushed last month — but experts such as Christopher McGrory Klyza of Middlebury College say the Obama team's hard work is only beginning.
The reversals undertaken "are the easiest things to move quickly on," says Klyza, co-author of a book on presidential environmental policy.
The hard work, such as filling in the details of how Obama will keep his campaign pledge to cut global warming gases 80% by 2050, lies in front of the new administration.
Christie Whitman, Bush's first chief of the Environmental Protection Agency, knows firsthand how hard that work can be, and she says it will be even harder for Obama. The time and political capital Obama will have to expend on the economic crisis will "make it much more complicated" for him to achieve his environmental and energy goals, Whitman says.
"They're hard enough anyway," she says.
Although Obama has the advantage of a Democratic-controlled Congress, party affiliation counts less than regional politics on many of the issues he wants to tackle. Democrats from heavily industrial Midwestern states, for example, are less eager to sign on to legislation to combat global warming.
"Whether they are Republicans or Democrats, they tend to be concerned about economic effects on their own states," says Reid Detchon of the non-partisan Energy Future Coalition, which promotes renewable energy.
In the budget unveiled Feb. 26 and in numerous pronouncements by Cabinet officials, the Obama administration has started to sketch out its environmental platform, but details are in short supply.
For example, the president's budget does not fund the Energy Department's plan to store nuclear waste at Yucca Mountain in Nevada.
The federal government has spent more than 25 years and $13 billion investigating a place to store highly radioactive waste.
Yucca was not likely to open until 2020, despite a 1998 deadline set by Congress for the government to take charge of nuclear waste. Obama's position could further delay finding a final resting place for the radioactive materials piling up at the nation's nuclear plants.
Some experts, such as Robert Alvarez, a top Energy Department official during the Clinton administration, want the government to pick a new site for storing the waste. Alvarez recognizes the political difficulties ahead. "Everybody will just get angry if they learn their backyard might be a candidate site," he says.
The budget assumes passage of a law to curb emissions of the gases responsible for global warming.
Obama wants Congress to pass a bill that would set a strict cap on emissions. Companies would be required to pay the government for the right to emit global warming pollutants.
The budget includes revenue of $646 billion from 2012 to 2019 from such payments. Some of the money would pay for a middle-class income tax cut, some for research on solving global warming.
A wide spectrum of groups — from the Environmental Defense Fund to the Edison Electric Institute, which represents power plants — agree on the need to cut greenhouse-gas emissions, but there is disagreement over how to do it.
Lawmakers, who failed to pass a bill last year, will have to decide how much to cut emissions and how soon.
"This is going to be a very complex piece of legislation," says Rep. Ed Markey, D-Mass., who chairs a House subcommittee key to passage of a global warming bill. "In the end, politics is the art of the possible."
What has been done, what lies ahead on president?s green agenda
USA TODAY'S Traci Watson takes a look at the actions President Obama has taken on key environmental and energy issues — and the hard work yet to be done.