In case you’ve been too busy composting, recycling and campaigning to rid the globe of toxins to remember the date, here’s a news flash for you: Today, April 22, marks the 40th anniversary of Earth Day.

Now, James Cameron would have you believe that the best way to celebrate this esteemed occasion is by purchasing Avatar on DVD and watching those big blue anteater-type-deals get their jollies by plugging their ponytails into each others orifices. While we have nothing in particular against Pandorans and what they do with their hair, we respectfully beg to differ with Mr. King of the World.

For our money, there’s no better way to spend Earth Day ’10 than by heading down to Battery Park and, you know, getting in touch with nature. And if the glorious 70-degree temps, the newly budding trees and the breathtaking water vistas aren’t enough to convince you, perhaps you’d be interested to know that BPC is sweetening the pot with a barrage of activities and art exhibits that are 100% free, 100% interesting and 200% eco-friendly.

In fact, Battery Park City’s cultural institutions have joined forces to produce a weeklong homage to the environment. Events began last Saturday, April 17, and continue through Sunday, April 25 — but some of the best stuff is going on right this very minute.

For example, artists Rod Tryon and Anthony Cappetto will be in the Winter Garden from 10 AM to 4 PM daily, from now until Saturday, using pastels to create a gorgeous 3-D Koi Pond drawing right before your very eyes (trump that, Cameron!)

Visitors to the Winter Garden can also check out Suzanne and Mathilde Husky’s art installation entitled Forest, a beautiful multicolored landscape composed of recycled clothes like your old socks and underwear (though hopefully not your old socks and underwear).

Other big draws are today’s 3:30 PM arts and crafts program at the World Financial Center (kids can make their own dreamcatcher using all recycled materials!); a 3 PM Climate Change Workshop at the Mercy Corps Action Center;  and a 6:30 PM Green Giants exhibit at the Museum of Jewish Heritage on how the Empire State Building and the Sears Tower are being retrofitted to become pals of the environment. Let’s just hope your old underwear doesn’t play a role there.

Check out http://www.batteryparkcity.org/nysgreenest/ for a full schedule of events.