A day to recycle, day to plant trees, day to overall respect and support the planet.
Recycling is just common sense.
Planting trees to replace trees used in industry is common sense as well.
So is the overall respect and having a personal connection to the nature.
I do understand that if a nations culture does not have these things innately then a publicity stunt like Earth Day can raise awareness, but celebrating Earth Day as an intellectual penance for being a consumer sounds silly to me.
Meh, courses for horses.