Credit: WhiteHouse.govCredit: WhiteHouse.govIn his State of the Union speech, President Barack Obama warned that Americans must take steps now to cut "our emissions of the dangerous carbon pollution that threatens our planet." To justify these efforts, he appealed to the "overwhelming judgment of science," pointing chiefly to recent weather extremes in the United States as evidence for the urgency of action. Reason Science Correspondent Ronald Bailey assesses the science and the policy and suggests a "balanced approach" to the president.