This April 22 marks the 40th anniversary of Earth Day.

From its beginnings as a grassroots protest to its place now as a worldwide event, Earth Day marks a collective feeling of conservatorial spirit.

When it started in 1970, few could have predicted its success, as nearly 20 million people gathered across North America to protest environmental destruction.

Earth Day is now an opportunity for many to recycle, reduce and reuse or organize and galvanize those around them.

Your assignment: What does Earth Day mean to you?

You can file a serious report or get creative. Just make sure you start your piece with, 'To me, Earth Day means ....'

Here's how you can get involved:

Video: We're looking for videos reports -- no more than two minutes in length. Feel free to film yourself -- or get a friend to help out. You can report on a local Earth Day event, or get creative and show us in your unique way, what Earth Day means to you. When you're done, upload your work in .wmv or .mp4  format to our video section. If you run into problems, email the video to yournews@cbc.ca and include "What Earth Day means to me" in the subject line.

Photos: Whether you're inspired by traditional photojournalism, and want to document a local event, or are the creative type who would rather go the route of interpretation, we're looking for your photos. All we ask is the photo a visual explanation of what Earth day means to you. Upload your photos to our Earth Day Gallery, Flickr page or email them to yournews@cbc.ca and include "What Earth Day means to me" in the subject line.

You can also upload your photos to our April "green" photo contest for a chance to win great prizes.

Stories: Have a lot to say about Earth Day? Tell us in your own words the importance of this event to you. Describe why and how you get involved. To get you started, consider the sentence, 'To me, Earth Day means...' Send in your stories or email them to yournews@cbc.ca and include 'What Earth Day means to me' in the subject line

Webcam: Feeling bold? Want to tell it straight to the audience? Turn on your webcam and tell us what Earth Day means to you. Just hit record and start talking. When you're done upload your work in .wmv or .mp4  format to our video section. If you run into problems, email the video to yournews@cbc.ca and include "What Earth Day means to me" in the subject line.

Twitter: Love social networking and have a flair for the short and sweet? Here's your chance to shine in 140 characters or less. Tweet us what Earth Day means to you @CBCYourVoice. Don't forget to include the hash tag #EarthDay in your tweet.

Facebook: Join our CBC News Fan group and post your thoughts on our wall. Begin your post with "To me, earth day means ...."

Deadline: We're looking for your contributions by April 21.

Questions? Drop us a line at yournews@cbc.ca