Pittsburgh ? President Barack Obama pressed Congress to scrap billions in oil company tax breaks and pass legislation to help the nation kick a dangerous “fossil fuel addiction” Wednesday, trying to channel disgust over the worsening oil disaster into a force for clean energy.

Seeking opportunity in a crisis, Obama argued for action in Congress as crews struggled into a seventh week to contain BP’s mangled oil well in the Gulf of Mexico. He urged lawmakers to shift the tax-break money toward clean-energy research and approve a major energy bill, now stalled in the Senate, that would slap a price on carbon emissions.

“Our continued dependence on fossil fuels will jeopardize our national security,” he declared. “It will smother our planet. And it will continue to put our economy and our environment at risk.”

Among the costs, Obama said in a speech at Carnegie Mellon University, is the risk that comes with drilling deep below offshore waters to find oil. He received sustained applause when he said, “We have to acknowledge that an America that runs solely on fossil fuels should not be the vision that we have for our children and grandchildren.”

Obama’s tough words about Big Oil came as he and oil giant BP face growing unhappiness from a public watching the disaster unfold day by day. What started with an oil rig explosion on April 20 has become the worst spill in U.S. history, with oil reaching shorelines and still gushing with no permanent fix in sight.

The Justice Department is investigating, and Vice President Joe Biden said Wednesday of BP: “My guess is that there are all kinds of discussions about whether or not they pushed the envelope with the rig operator beyond what it should be pushed to safely pursue.” Biden, in a pretaped interview for Charlie Rose’s PBS talk show, said that if any civil or criminal violations are found “they will be pursued to the extent of the law.”