Today is World Earth Day
Today is Earth Day 2017, so it's the perfect time to start thinking about the planet we live on - and how to save it.
Every year, more than one billion people across the world mark the event by showing support for environmental protection.
Festivals, rallies and outdoor events are held in nearly 200 countries - often, with the support of A-list celebrities and political leaders.
But why do we celebrate Earth Day? And how is it observed by people globally?
Here, we provide a guide to the event, which takes place on April 22 each year.
Each year, festivals, parades and rallies are held in at least 192 countries to demonstrate support for environmental protection.
The day has its own flag, which was created by US peace activist John McConnell and, perhaps unsurprisingly, features a picture of the world on it.