When Nobel-prize winner and Secretary of Energy Dr. Steven Chu was asked by a New York Times reporter if he preferred to be called “Mr. Secretary” or “Dr. Chu,” his response—“Steve is fine”—was telling. This down-to-earth, low-profile research scientist from outside the Washington circle was tapped by President Barack Obama to transform the country’s energy policy.

In contrast to his 11 energy predecessors, Chu’s credentials are scientific, not political.

His mission? A nation fueled by clean energy. Chu is a vocal advocate of aggressively controlling emissions, holding the most adamant views on global climate change of any previous Cabinet member. He supports transformational technology and energy efficiency.

“The potentially adverse effects of global greenhouse-gas emissions…are well established today,” he told the Senate Committee on Energy and Natural Resources in March 2009. “If we, our children, and our grandchildren are to prosper in the 21st century, we must decrease our dependence on oil, use energy in the most efficient ways possible, and decrease our carbon emissions. Meeting these challenges will require both a sustained commitment for the long-term and swift action in the near-term.”

At his nomination hearings, Chu promised Republicans he would put domestic nuclear power on a fast-track and accept oil and gas drilling as part of a broad energy package. To Democrats, he promised to champion solar energy and develop a “smart” power grid to bring wind power from remote areas.

“We need all solutions,” he said. “We need to make them as clean as possible as quickly as possible.”

Chu was born in St. Louis, Missouri, into a family of scholars and grew up on Long Island, New York. His father emigrated from China and earned a degree in chemical engineering from MIT, where his mother studied economics.

He received his math and physics degrees from the University of Rochester and a doctorate in physics from the University of California at Berkeley. He has headed research at Bell Labs, and chaired the physics department at Stanford. In 1997 he received the Nobel Prize in physics for his research in cooling and trapping atoms using lasers.

Following his Nobel, Chu became convinced that global warming was the greatest threat to mankind—his belief was so genuine that he changed fields to combat climate change.

In 2004, he was named director of the Lawrence Berkeley National Laboratory, with 4,000 employees and a $650-million budget. The lab is owned by the Energy Department and is under contract by the University of California. Chu retooled the lab’s focus to research “carbon-neutral” sources of energy, particularly advanced biofuels, artificial photosynthesis and other solar-energy technologies.

He initiated the Helios project, an endeavor to harness solar power as a source of renewable energy for transportation, and helped form the Energy Biosciences Institute, a consortium funded by BP Plc to study biofuels.

In his role at DOE, Chu seeks to “reenergize our national labs as centers of great science and innovation,” to effect transformational change that is “game-changing.”

He seeks a quantum leap in areas such as: gasoline and diesel-like biofuels generated from lumber waste, crop wastes, solid waste and non-food crops; automobile batteries with two to three times the energy density and that can survive 15 years of deep discharges; photovoltaic solar power that is five times cheaper than today’s technology; computer design tools for commercial and residential buildings that enable reductions in energy consumption of up to 80%, with investments that will pay for themselves in less than 10 years; and large-scale energy storage systems so that variable renewable energy sources such as wind or solar power can become base-load power generators.

In 2007, before a group of Berkeley students, Chu said “coal is my worst nightmare,” but he doesn’t believe developed and developing countries like the U.S., China, Russia or India will give up coal anytime soon. Thus his next best hope is technology to develop so-called “clean coal” and carbon capture sequestration (CCS), projects into which DOE has funneled some $3.4 billion in research from federal stimulus funds.

For his part, Chu is a hesitant proponent of nuclear power. “Nuclear power will be part of our energy going forward, because it is carbon-free and because it is base load. Now, having said that, we don’t have all the answers today as to how to develop that in a way that would make us all happy, particularly about waste.”

While Chu believes transformational technology is key to long-term change, he also believes energy efficiency is critical in the interim—the “low-hanging fruit.” He has proposed painting all flat roofs in America white, and all sloped roofs a more aesthetic “cool gray,” which he says will save the equivalent of removing the carbon emissions for all the cars on the road for 11 years. He told the Chinese that the energy saved by energy-efficient refrigerators in the U.S. is more than the power that will be generated by the massive Three Gorges dam project under development in China.

Recognizing that China now leads the U.S. as the greatest carbon-emitting country on the globe, perhaps President Obama chose this Chinese-American scientist to head his energy department with partnership-building in mind. In a speech in July at China’s Tsinghua University, Chu noted that while developed nations are largely culpable for existing carbon in the atmosphere, China is on track to emit more carbon in the next three decades than has the U.S. in its history. “We are all in this together, so we have to fix it together,” he said.