On Earth Day, we're taking a look at some of the most shocking images that show how our climate is changing. This story was originally published on April 22, 2015.This Earth Day, more than 160 world leaders will sign the Paris Climate Agreement at the United Nations headquarters in New York City.They will do so on a (very) warm spring day. Last year surpassed 2014 as the hottest year on record, and the first three months of 2016 have already eclipsed prior record highs for these months, according to CBC.

Despite overwhelming evidence that the climate is changing and human activity is to blame — 97% of all working climate scientists, the United Nations, the President of the United States, and NASA agree — the GOP presidential candidates are skeptical. Senator Ted Cruz has called climate science "religion," and Governor John Kasich has said man-made climate change is "some theory that's not proven," according to ThinkProgress Donald Trump has tweeted that "global warming is a concept created by and for the Chinese in order to make U.S. manufacturing non-competitive."It was only a little over a year ago that Senator Jim Inhofe, the Chair of the U.S. Senate Committee on Environment and Public Works , tried to disprove the concept of global warming by bringing a snowball into the United States Senate. (Because the fact that there is still winter means the climate isn't changing?)We put together this slideshow as a reminder that climate change is real and needs to be taken seriously — by all of us.