Earth Day is the "modernized" version of a pagan celebration in which people used to sacrifice animals, and sometimes other people, to celebrate the end of winter and the start of spring. They sacrificed to appease whatever gods of fertility they worshipped (depended on the tribe and part of the world).
I don't plan on sacrificing anything or anyone today. In fact, I might just turn on everything in the house, crank up the air conditioning (its already in the upper 90's here in the Mojave Desert), go for a long drive for no reason and who know what else I can come up with just to counter the nonsense that is "going green" on Earth Day or any day. The climate has changed dramaticly many times over the centuries. It's been through several ice ages and warming trends long before humans started doing anything more than burning a few fires. It's just a cycle of warming and cooling that we have nothing to do with and can do nothing about.