The campaign for the 35-year-old event, created by 23red, takes place on June 5 and focuses on the line "the mend of the world is now". It highlights everyday actions the public can take to help combat climate change, such as riding a bike rather than driving a car.
Sean Kinmont, creative director at 23red, said: "Central to the brief was the need to develop something positive and motivating out of a topic that is really big and scary."
Other actions featured in the campaign include drying washing outdoors, turning appliances off and using reusable bags; these are all combined with dramatic images of a sun scorched earth.
23red was hired by the Environment Agency to develop the United Nations inspired campaign in the UK, which will be backed up by regional PR events and partnerships with brands including utilities firm Centrica, retailer IKEA and Barclays bank.
Greg Brina, the Environment Agency's World Environment Day manager, said: "There's an awful lot of information out there, so 23red's brief was very much to cut through that noise. The campaign will form the backbone of what we hope will be not just a memorable day, but a catalyst to real behaviour change."