President Barack Obama promised to take action on climate change in his inaugural speech, putting the issue at the forefront of his agenda for the second term. Americans’ obligations are not just to self, “but to all posterity,” Obama said. “We will respond to the threat of climate change, knowing that the failure to do so would betray our children and future generations.”

The strong language suggests that recent efforts by environmentalists to appeal to the president’s sense of legacy on the issue have hit home. The issue was central to the otherwise limited and brief speech, where the president spoke of the tenets of the Declaration of Independence, health care and war. The president also asserted that he hopes to push forward on making the U.S. a world leader in renewable energy.