Earth Day is being marked all over the world today and Google is getting in on the action by featuring a colourful and interactive doodle on its homepage to mark the cycle of seasons.
Each year Earth Day is celebrated on 22 April since the day was first marked on this day in 1970. Head to the Google homepage today and you will be met with a stylised Google logo that has been transformed into a colourful landscape.
Click on the sun to see it rising and setting before the moon starts to rise in a night sky. This day and night scene happens repeatedly as the moon goes through its different phases and the doodle changes to reflect different seasons.
The Earth Day concept was first brought to light at a UNESCO conference in San Francisco, California, in 1969 by the peace activist John McConnell. Former US senator Gaylord Nelson then founded Earth Day in the US after a massive oil spill in Santa Barbara, California, in 1969.
Earth Day was first celebrated when some 20m Americans took to the streets and parks to demonstrate for a healthy, sustainable environment. The day is widely credited with having ignited the modern environmental movement.
The Earth Day Network works with more than 22,000 partners in 192 countries to highlight environmental campaigns, to help promote environmental education and to raise awareness of mobilising a global green economy.
This year, the Earth Day Network is inviting people to post photos on its website to show how climate change has impacted them. The idea is to create a Face of Climate Change mosaic.
Today in Ireland, 40 students will be converging at Blackrock Castle Observatory in Cork to engage in a live link-up with NASA as well as other students across the globe. NASA climate scientist Claire Parkinson will be explaining how scientists are studying the planet using data from NASA space satellites and instruments.