Senator Barack Obama presented a plan on Monday to decrease the nation’s dependence on foreign oil and fight global warming by creating an auction system requiring power companies and other industries to pay for their pollution. By the year 2020, he said, emissions would be reduced to levels from 1990.
In a speech in New Hampshire, Mr. Obama, the Democratic presidential candidate from Illinois, called for imposing a national cap on carbon emissions, investing $150 billion over 10 years to develop new energy sources and reducing dependence on foreign oil by 35 percent by 2030.
“No business will be allowed to emit any greenhouse gases for free,” Mr. Obama said in Portsmouth, N.H. “Businesses don’t own the sky, the public does, and if we want them to stop polluting it, we have to put a price on all pollution.”
The energy speech was the latest effort by Mr. Obama to cast himself as a critic of how business has been conducted in Washington. Every president since Gerald R. Ford, Mr. Obama argued, has pledged to curb fossil fuel use, but the United States’ dependence on foreign oil has climbed.
He proposed instituting a mandatory “cap and trade” program across the economy to reduce greenhouse gas emissions to the level recommended by top scientists, a figure that he did not specify Monday. Under his plan, businesses would be required to buy allowances to pollute, which would create financial incentives to limit energy use or reduce emissions.
Mr. Obama said if he was elected, the government would set a national cap on carbon emissions, which by 2050 would be reduced to 80 percent below the levels in 1990. Though he did not mention his campaign rivals by name, Mr. Obama criticized those who opposed gradual increases in gasoline mileage standards for cars, which included Senator Hillary Rodham Clinton of New York.
“When they had the chance to stand up and require automakers to raise their fuel standards, they refused,” Mr. Obama said. “When they had multiple chances to reduce our dependence on foreign oil by investing in renewable fuels that we can literally grow right here in America, they said no.”
Mr. Obama, who had faced criticism from some environmental groups for supporting the Bush administration’s energy bill in 2005 and for pushing legislation to help Illinois’ coal industry, was praised Monday by the League of Conservation Voters, an independent group. The group’s president, Gene Karpinski, said, “By embracing a mandatory cap-and-trade program, the Obama energy plan would provide incentives to cut production of carbon dioxide and other pollutants that cause global warming.”
In Iowa, meanwhile, Mrs. Clinton began a “rebuilding the middle class” bus tour on Monday that included a 50-minute speech on economic prosperity with new proposals to benefit unions and homeowners in particular.
Speaking in Cedar Rapids, she called for reviewing pacts like the North American Free Trade Agreement every five years — not as aggressive a position as John Edwards’s call for renegotiating Nafta or Representative Dennis J. Kucinich’s call for canceling it, but an idea that received applause nonetheless.
And she proposed giving Fannie Mae and Freddie Mac new flexibility to help companies and homeowners replace expiring adjustable-rate mortgages with fixed-rate loans.