Climate change is no longer a distant threat, but a clear and present danger. That’s the main takeaway from the third installment of the National Climate Assessment (NCA), released this week by the White House.
The report itself is a feat of both exhaustive climate science and creative science communications. The 840-page document is packed with illustrative graphics, and the web-based version features interactivity and video. Beyond painting the national picture, the NCA presents, in the words of White House science advisor John Holdren, “unprecedented detail about regional impacts” of climate change.
“Climate change is not a distant threat, but is affecting the American people already,” says Holdren in a video introducing the report. “Summers are longer and hotter, with longer periods of extended heat. Wildfires start earlier in the spring and continue later into the fall. Rain comes down in heavier downpours. People are experiencing changes in the length and severity of allergies. And climate disruptions to water resources and agriculture have been increasing.”
Some quick background: The U.S. Global Change Research Program was formed by Congressional mandate in 1990, and charged with producing regular “National Climate Assessments” in order to “highlight key knowledge that can improve policy choices and identify significant gaps that can limit effective decision making.” The NCA reports are compiled by a 60-member federal advisory committee made up some scientists, business leaders, and other climate experts, and the content itself is written by nearly 300 scientists, academics, government and private sector experts. The document itself is subjected to exhaustive review, including by the National Academy of Sciences. And as a consensus-based document, the findings must be approved by representatives of such disparate parties as environmental groups and fossil fuel companies. If anything, this report is conservative in its findings.