Today (April 22) is Earth Day, an international event celebrated around the world to pledge support for environmental protection. This year 2021 marks the 51st anniversary of the annual celebrations. This year's theme for Earth Day is 'Restore Our Earth.' Earth Day Activities and Ideas. Support Our Pollinators! Clean Up Plastic in our Neighborhood! Swap Out Our Kitchen and Household Products! Plant a Tree! Reduce, Reuse, Recycle in the Garden. Stop Pesticides and Chemicals in the Garden.