Activists celebrate the global climate change agreement reached in December 2015 in Paris. Officials from more than 170 nations came to New York on Earth Day to sign the pact in a ceremony at the United Nations.
Activists celebrate the global climate change agreement reached in December 2015 in Paris. Officials from more than 170 nations came to New York on Earth Day to sign the pact in a ceremony at the United Nations. Michel Euler Associated Press file
Activists celebrate the global climate change agreement reached in December 2015 in Paris. Officials from more than 170 nations came to New York on Earth Day to sign the pact in a ceremony at the United Nations. Michel Euler Associated Press file

Earth Day reminds us of the challenges of cooperation

April 22, 2016 08:47 AM