Today, 22nd April 2010, is the 40th anniversary of Earth Day, an event that was started in America to encourage people to engage with the environmental problems we face as a global community.

Since it began in 1970, it has prompted millions of people to take action to mitigate climate change, expanding to become a worldwide campaign in 1990, with more than one billion people in 190 countries now taking part.

Earth Day was founded by US senator Gaylord Nelson in 1970. He found that increasing numbers of people were becoming concerned about the need to protect the planet for the future, and felt that if people could unite and show that this was concern shared by people all across the country, in different constituencies and from different organisations and groups, then Washington would be encouraged to put the environment on the political agenda.

For the first time in modern history, groups who’d been campaigning on separate issues – from oil spills to animal rights – united under a single banner to campaign for the environment. It was a massive success, with around 20m people across America taking part.

This year, Earth Day 2010 aims to unite the environmental community worldwide to take action against climate change and call for the creation of a proper green economy.

It’s not just about campaigning, though, it’s also about education, and ensuring that more and more people understand the risks posed to us and our environment by climate change. This year’s event is based around ‘three pillars’, which are:

• Service - large and small-scale projects from tree plantings to light bulb switch-out campaigns, home energy efficiency retrofits, greening schools and water projects, all geared to lower carbon footprints;
• Advocacy - Earth Day Network and partner organisations will hold The Climate Rally in Washington DC, USA, to call for climate and clean energy legislation that will create jobs and reduce carbon emissions;
• Celebration - hundreds of thousands of people are expected to celebrate Earth Day’s 40th anniversary in cities across the world with official events featuring musical talent, speakers and eco-villages where attendees can learn how to adopt green practices in their daily lives.

We love the Earth Day philosophy of uniting different groups into one global community fighting for the same thing. Though we may have different specific goals we want to achieve, our overall aim is the same: to safeguard and protect our environment for the future.

You can join in too by pledging to take specific action, taking part in an event near you, or setting up your own. Find out more.