1. The document discusses the history and impact of the National Climate Assessment (NCA) report published in 2000 and subsequent reports issued in 2009, 2014, and 2018.
2. It outlines how the reports have documented the impacts of climate change across different regions of the United States, including rising temperatures, increased heavy downpours, more severe wildfires and hurricanes.
3. The assessments have provided evidence that climate change poses a significant risk to Americans' physical, social, and economic well-being but some policymakers remain unconvinced of the urgency for action.
