How the Environment Has Changed since the First Earth Day 50 Years Ago (Andrea Thompson, SA, 2020-4-22)

https://www.scientificamerican.com/article/how-the-environment-has-changed-since-the-first-earth-day-50-years-ago/?utm_source=newsletter&utm_medium=email&utm_campaign=earth&utm_content=link&utm_term=2020-04-22_featured-this-week&spMailingID=64589589&spUserID=MTEwMTQwMDYwODYS1&spJobID=1862669127&spReportId=MTg2MjY2OTEyNwS2