elect Barack Obama underscored on Saturday his intent to push initiatives on climate change by naming John Holdren, an energy and climate specialist, as the new White House science adviser. Holdren is a Harvard University physicist who has focused on the causes and consequences of climate change and advocated policies aimed at sustainable development. He has also done extensive research on the dangers of nuclear weapons. Obama pledged to put a priority on encouraging scientific breakthroughs in areas such as alternative energy solutions and finding cures to diseases, as he announced the pick of Holdren and other top science advisers in the Democratic weekly radio and video address. “Today, more than ever before, science holds the key to our survival as a planet and our security and prosperity as a nation,” Obama said. “It's time we once again put science at the top of our agenda and worked to restore America's place as the world leader in science and technology.” “From landing on the moon, to sequencing the human genome, to inventing the Internet, America has been the first to cross that new frontier,” Obama said. He said government has played an important role in encouraging those breakthroughs and could do so in the future. The Bush administration has had a rocky relationship with the scientific community and was at times accused by critics of ignoring scientific evidence in its efforts to make political points on issues such as global warming. Holdren, who teaches at Harvard's Kennedy School of Government, will head the White House Office of Science and Technology Policy. He is a former president of the American Association for the Advancement of Science. Obama, who takes office on Jan. 20, this week finished naming Cabinet secretaries for his incoming administration. On Friday, he introduced his choices of Illinois Republican congressman Ray LaHood to head the Transportation Department and California Democratic Rep. Hilda Solis to be secretary of labor. After working for weeks to assemble his team, Obama leaves for Hawaii for a Christmas vacation with his family. Obama has named Steven Chu, winner of the 1997 Nobel Prize in physics who was an early advocate for finding scientific solutions to climate change, to head the Energy Department.