"Now that you're done with finals, help us meet the climate change test," United Nations Secretary General Ban Ki-moon told Columbia University graduates last week.
After receiving an honorary doctorate of laws from the university, Ban told the crowd that April marked the seventh straight month of the "hottest global temperatures on record," and he said students must help bring the Paris climate agreement to life:
"Don't vote for politicians who deny the problem," he said. "Don’t buy products that aren’t sustainable. And for heaven’s sake, turn off the lights!"
Ban also railed against the "racism and hatred" of politicians and "would-be leaders who have a duty to bring people together, not drive them apart."
As technology connects people, he said the challenge is to "be more united."