Launched by US Senator Gaylord Nelson in 1970 to politicise the green agenda, the first Earth Day was celebrated by 20 million people. Now in its 37th year, the event is observed by 500 million people and acknowledged by governments in 175 countries.

As mentioned last month, Kaiser Chiefs will commemorate Earth Day by participating in a series of gigs held in three US cities from 20th to 22nd April. But it’s not just rock stars that are marking the occasion.

From encouraging people to recycle to cleaning up local conservation areas, changing light bulbs to planting trees, communities across the world are planning local events and campaigns to raise awareness of climate change and educate people to fight back. Here’s our pick of just some of the ways Earth Day is being commemorated:

In the US, the giant retailer Home Depot will give away one million CFL light-bulbs at its stores across the country.

In Canada, a march has been organised by Montreal environmentalists to protest the government’s inaction over the Kyoto Protocol.

In Thailand, the Sila Evason Hideaway and Spa at Samui is hosting a beach and coral clean-up on the island of Koh Samui.

And in the UK, IT company Maxitech is calling on Londoners to pay them a visit this weekend and donate their old PCs, mobiles and other technical equipment for those less fortunate. Equipment that cannot be refurbished will be ‘e-cycled’.

From all of us at Global Cool, have a very happy Earth Day.Click here for Earth Day website