For me, I used a air blower to sweep all the pigeon crap off the roof and placed silver reflective boarding to reflect some of the heat back into space. My mother is currently mowing the lawn. Ah, cutting the greens and polluting the air we breathe.
Hey WTF happened to arbor day?
I celebrated by turning over the Winter Rye in my vegetable garden. All the leaves that my neighbors were only too happy to give me last Fall have all rotted down nicely in my compost with some horse puckey, eel grass seaweed, houshold veggie and egg scraps and my lawn clippings to make some nice compost. I spread that over the freshly-turned earth and now all I need is May to come and I can start planting my veggies!
I do not bring water bottles to work anymore. I have one that I refill at the water fountain. Of course, I believe the fountain is refrigerated with environmentally unfriendly chemicals.
I ride the bus every day... and use water frim a well in our garden to water our yard
Bringing my lunch (leftovers) in a reusable container and using only a table lamp at work instead of the overhead fluorescents.
Edit: This is something that I do everyday, not just because it's Earth Day.
I helped plant 20+ trees O:)