"Climate change is a growing and pressing problem. It's now clear that if we continue on our current path, we run the risk of dramatic, disruptive changes to our climate in the lifetimes of our children and grandchildren," he told the Senate Energy and Natural Resources Committee.
Chu said he would press for a cap-and-trade system to lower greenhouse gas emissions, which would require power plants and other greenhouse gas emitters to buy and sell pollution permits.
Chu won the Nobel Prize in physics in 1997, for experiments in which he used laser light to trap and study atoms. In recent years he's turned his attention to energy research. As head of the Energy Department's Lawrence Berkeley National Laboratory, he's refocused the lab's research efforts on renewable energy.
In his prepared testimony Tuesday, Chu softened some of his earlier statements on rising gas prices, a New York Times blog pointed out. Last September, he told the Wall Street Journal that "somehow we have to figure out how to boost the price of gasoline to the levels in Europe."
But in his confirmation hearing he said that "last year's rapid spike in oil and gasoline prices not only contributed to the recession we are now experiencing, it also put a huge strain on the budgets of families all across America."
His confirmation is expected to pass easily. Committee chairman Sen. Jeff Bingaman (D-N.M.) said Chu has "insight and vision," and that a committee vote on his nomination would likely occur later in the week, according to the Associated Press.
Sen. Lisa Murkowski (R-Alaska) also called Chu "well-qualified," but questioned his positions on offshore oil drilling and nuclear energy, the AP reported.
In response, Chu said that nuclear energy "is going to be an important part of our energy mix."
He also said that the administration would consider expanded offshore drilling as part of its energy policy, but noted that the United States holds only 2 percent of the world's oil reserves.
"Improvements in energy efficiency is the one single factor that can most reduce our dependency on foreign oil," he said.
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