The White House stressed Tuesday the need for "urgent action" to fight the threats of climate change. The U.S. Administration unveiled the third U.S. National Climate Assessment, which is "the most comprehensive scientific assessment ever generated" of climate change and its impacts across every region of America and major sectors of the U.S. economy. The findings in the National Climate Assessment underscore the need "to protect American citizens and communities today, and build a sustainable future for our kids and grandkids." Developed over four years by hundreds of the Nation?’s top climate scientists and technical experts, the third National Climate Assessment represents "the most authoritative and comprehensive knowledge base about how climate change is affecting America now, and what?’s likely to come over the next century." The Assessment stressed that "climate change, once considered an issue for a distant future, has moved firmly into the present." "Long-term, independent records from weather stations, satellites, ocean buoys, tide gauges, and many other data sources all confirm that our nation, like the rest of the world, is warming," the Assessment shows. It noted that "precipitation patterns are changing, sea level is rising, the oceans are becoming more acidic, and the frequency and intensity of some extreme weather events are increasing." "Many lines of independent evidence demonstrate that the rapid warming of the past half-century is due primarily to human activities," it stressed. Global climate is projected "to continue to change over this century and beyond, but there is still time to act to limit the amount of change and the extent of damaging impacts." The White House said that "today?’s announcement is a key deliverable of the Climate Action Plan launched by President Obama last June, which lays out concrete steps to cut carbon pollution, prepare America?’s communities for climate-change impacts, and lead international efforts to address this global challenge." The Plan acknowledges that "even as we act to reduce the greenhouse-gas pollution that is driving climate change, we must also empower the Nation?’s communities, businesses, and individual citizens with the information they need to cope with the changes in climate that are already underway