Earth Day: What is it, when is it and why is it important?

This article has been updated.

• Earth Day takes place every year on 22 April and is one of the biggest environmental protest movements on the planet.
• The theme of Earth Day this year is ‘Our Power, Our Planet’ – calling for people across the globe to unite behind renewable energy, and to triple the global generation of clean electricity by 2030.
• The World Economic Forum’s Global Risks Report 2025 finds that environmental risks make up half of the top 10 risks over the next 10 years.

“Good evening, a unique day in American history is ending. A day set aside for a nationwide outpouring of mankind seeking its own survival.”

Those were the words of US TV presenter Walter Cronkite as he described the aftermath of the first Earth Day back in 1970.

Here’s what you need to know about Earth Day in 2025.

Earth Day is an international day devoted to our planet. It draws attention to the environment and promotes conservation and sustainability.

Each year on 22 April, around 1 billion people around the world take action to raise awareness of the climate crisis and bring about behavioural change to protect the environment.

Participation in Earth Day can take many forms, including small home or classroom projects like planting a herb garden or picking up litter. People also volunteer to plant trees, join other ecological initiatives or take part in street protests about climate change and environmental degradation.

The global theme for this year’s Earth Day is ‘Our Power, Our Planet’ – calling for people across the globe to unite behind renewable energy, and to triple the global generation of clean electricity by 2030.

Millions of people took to the streets of US cities and towns on 22 April 1970 in mass protests over the damage being done to the planet and its resources.

Amid the demonstrations, protesters brought New York City’s usually bustling Fifth Avenue to a halt, while students in Boston held a “die-in” at Logan Airport.

The environmental impact of the post-war consumer boom was beginning to be felt at that time. Oil spills, factory pollution and other ecological threats were on the rise, with little if any legislation in place to prevent them.

The protests brought together people from all walks of American life – accounting for about 10% of the US population – to demonstrate and voice their demands for sustainable change. The Earth Day website calls it the birth of the modern environmental movement.

Concerned about increasing levels of unchecked environmental destruction, Junior Senator Gaylord Nelson of Wisconsin suggested a series of “teach-ins” on university campuses across the US in 1969 to raise awareness of environmental threats.

Nelson was joined by Congressman Pete McCloskey and activist Denis Hayes to organize the teach-ins, but the group soon recognized an opportunity to broaden the event’s appeal beyond student populations.

The newly named Earth Day protest events attracted national media attention and support from around 20 million Americans across age and political spectrums, occupations and income groups.

And as citizens were increasingly concerned with corporate impacts on the natural environment, big and small businesses started to feel the pressure to consider sustainability in their practice.

As the millennium loomed, the Earth Day movement turned its attention to the growing reality of the impending climate crisis with a clear message for world leaders and business: urgent action is needed to address global warming.

It’s a message that is even more relevant today. Analysis from the Intergovernmental Panel on Climate Change states that without further immediate action to curb greenhouse gas emissions, the world is on course for temperatures 3.2°C above pre-industrial levels by 2100. This level of warming would be catastrophic for the planet and all life on it, including humans.

The past 10 years, 2015-2024, were the 10 warmest years on record, according to the World Meteorological Organization. Last year was likely to have been the first calendar year with a global mean temperature of more than 1.5°C above the pre-industrial level – at about 1.55°C above the 1850-1900 average.

The World Economic Forum’s Global Risks Report 2025 finds that environmental risks make up half of the top 10 risks over the next 10 years, with extreme weather events, biodiversity loss and ecosystem collapse and critical change to Earth’s systems being the top three.

Earth Day has become a leading light in the fight to combat climate change and nature loss. As we celebrate its 55th anniversary, we must make use of this truly global movement to act, as citizens and governments, as consumers and businesses, and as individuals and communities. Our survival could well depend on it.