Climate impacts grow, and U.S. must act, says new report

Today, U.S. government agencies released a heavily anticipated new report about how climate change is impacting the United States. The 4th National Climate Assessment (NCA4) lays out a detailed picture of how communities across the country are already feeling the effects of climate change—from intensified risk of wildfires in California, to droughts slowing agricultural production in Iowa and much more.

The report is the second half of a vast effort by scientists, land managers, public health officials, and others to assess the state of the climate across the U.S. The report's first volume, published in 2017, summarized the state-of-the-art knowledge about how climate is affecting temperatures, water resources, sea-level rise, and other natural systems around the country. The second half, published today, focuses on how climate change is already tugging at the economic and social fabric of the United States.

In clear, unwavering terms, the new report states that without "substantial and sustained reductions" in greenhouse gas emissions, climate change will hurt people, economies, and resources across the U.S. But the report also highlights how its worst impacts can be avoided, by adapting to our warmer world and by working to lessen future changes in Earth's climate.

“It joins the mounting evidence about the scope and magnitude of climate-change impacts,” says Jupiter Intelligence director Julie Pullen, an ocean scientist at Jupiter Intelligence who reviewed an earlier version of the report. And because the report drills down into the local-scale impacts, Pullen adds, it gives Americans a realistic view of exactly how climate change influences their day-to-day experiences.

News from the future

As the report makes clear, different parts of the country face different risks posed by climate change. In vulnerable Southeastern states, coastal flooding is projected to increase dramatically; Charleston, South Carolina, could experience 180 tidal floods in a year by 2045, compared to 11 per year in 2014. In the Southern Great Plains, extreme heat could cause thousands of premature deaths and billions in lost work-hours by the end of the century. Echoing the 2017 scientific report, the new volume reinforces that human activity—primarily the release of greenhouse gases—is the culprit.

To continue reading: https://www.nationalgeographic.com/environment/2018/11/climate-change-US-report0/