Crosstalk: April 23, 2015

Earth Day, which started in 1970, was founded in part to promote environmentalism. But it has also been complicit in the dissemination of false or exaggerated information. Early predictions were that the earth would be 12 degrees colder by the year 2000, double what would be needed to start a new ice age, and that increasing nitrogen in the atmosphere would eventually filter out all light, making the earth's surface unusable.