The Climes They Are a Changin’

This week the U.S. Global Change Research Program released the Fourth National Climate Assessment (NCA4), also known as the Climate Science Special Report (CSSR). The report is “designed to be an authoritative assessment of the science of climate change, with a focus on the United States, to serve as the foundation for efforts to assess climate-related risks and inform decision-making about responses.” A team of scientists from “Federal agencies, national laboratories, universities, and the private sector” authored the fifteen chapter, 470-page report over the course of 18 months beginning in April of 2016.

According to the report, it provides:

1) an updated detailed analysis of the findings of how climate change is affecting weather and climate across the United States;

2) an executive summary and other CSSR materials that provide the basis for the discussion of climate science found in the second volume of the NCA4; and

3) foundational information and projections for climate change, including extremes, to improve “end-to-end” consistency in sectoral, regional, and resilience analyses within the second volume.

The report also concludes that it is “extremely likely that human activities, especially emissions of greenhouse gases, are the dominant cause of the observed warming since the mid-20th century. For the warming over the last century, there is no convincing alternative explanation supported by the extent of the observational evidence.”

Find the full report here on the HSDL.