"The nation that leads the world in creating new sources of clean energy will be the nation that leads the 21st century global economy," Mr. Obama said in his first return to Iowa, the state that launched him toward the White House. "America can be that nation. America must be that nation."
Mr. Obama's message came as his energy legislation has slowed in Congress. Skeptical Republicans and some Democrats from coal-producing states complain that it will increase costs for consumers, send jobs overseas and hurt businesses.
The president contends his approach will protect the environment while also creating jobs at a critical time for the economy.
"The choice we face is not between saving our environment and saving our economy, it's a choice between prosperity and decline," he said.
Mr. Obama said the nation needs more domestic production of oil and natural gas in the short term. But "the bulk of our efforts," he said, must focus on transitioning the U.S. to more renewable energy.
For his remarks, he chose Iowa, second only to Texas in installed wind capacity.
Mr. Obama announced that his administration is creating the nation's first program to authorize offshore projects to generate electricity from wind and ocean currents. Later in the afternoon, the Interior Department is issuing the final rule governing the development of offshore wind and tides.
Mr. Obama said that wind could generate as much as 20 percent of the U.S. electricity demand by 2030 if its full potential is pursued on land and offshore. It would also create as many as 250,000 jobs, he said.
"As with so many clean energy investments, it's win-win: good for environment and great for our economy," the president said.
But wind-produced electricity totals just under 2 percent of all electricity generated, according to the American Wind Energy Association, a trade group. And while green energy work has created jobs, the numbers fall far short of what once existed in some cities and towns.
In Newton, Maytag once employed 4,000 people from a town of 16,000. The new wind energy plant has 90 people working, a number that could group to 140.
During his political campaign, Mr. Obama touted wind as a prime source of renewable energy. Aides say he's remains steadfast in his support for an energy plan that would reduce greenhouse gases by 20 percent from 2005 levels by 2020, and 83 percent by mid-century.
Mr. Obama's plan also calls for a series of measures aimed at reducing the use of fossil energy, such as requiring utilities to produce a quarter of their electricity from renewable sources.
The backdrop for Mr. Obama's Earth Day commemoration was economically struggling Newton, whose biggest employer was sold and then stopped operations.
Newton's Maytag Corp. appliances plant closed in 2007, costing the small city hundreds of jobs. But a year later, the state announced that Trinity Structural Towers would build a $21 million factory on the former Maytag site and employ about 140 workers, in exchange for business incentives and tax breaks.
Mr. Obama's energy plan would drive more investments to companies such as Trinity, which builds the towers that support wind turbines.
The administration's economic stimulus plan also included some $5 billion for low-income weatherization programs and $2 billion for electric car research. Another $500 million was set aside to train workers for "green jobs," such as those at Trinity Structural Towers.
CBS News White House correspondent Mark Knoller notes that it was hardly a low carbon impact Earth Day for Mr. Obama. To get to and from Iowa for his speech on energy conservation and alternative fuels, he took two flights on Air Force One and four flights on Marine One.
Mr. Obama's carbon footprint was a big topic on Iowa talk radio, reports CBS News White House correspondent Peter Maer. In addition to the president's aircraft, callers cited press buses, the press charter and police vehicles.
Mr. Obama's post-inauguration travel itinerary reads like a list of battleground and Republican-leaning states that helped lift him to the presidency and will be critical in any re-election bid. He's visited Colorado, North Carolina, Indiana, Ohio and Florida. The visit to Iowa Wednesday was his first since the election.
Mr. Obama staged a surprise upset over one-time rival Hillary Rodham Clinton to win Iowa's caucuses in January 2008, giving him much-needed momentum out of the caucuses that sparked a marathon nomination struggle. His Iowa field operation for 2012 is up and running, with town-hall meetings scheduled this week.
The House began four days of hearings on climate legislation Tuesday, but the challenge of getting bipartisan support immediately became apparent. Energy Secretary Steven Chu, EPA Administrator Lisa Jackson and Transportation Secretary Ray LaHood reinforced Obama's message in testimony Wednesday.
The administration officials expressed broad support for a House Democratic bill but indicated the White House would work with Congress on the specifics of the legislation.
In Landover, Md., Vice President Joe Biden marked Earth Day by announcing that $300 million in federal stimulus money will go to cities and towns to purchase more fuel-efficient vehicles. State and local governments and transit agencies are eligible to apply for the funds, though they must agree to match half the amount they are allocated.