The 48th Earth Day celebrations on Saturday saw participation from school children in awareness drives, campaigns in social media, emotional appeals from MNCs and a request from Prime Minister Narendra Modi to keep the planet clean and green.

While describing the Earth Day "a day of gratitude to mother earth", Modi said: "It is our duty to live in harmony with the plants, animals and birds we share the earth with. We owe this to our future generations."

He hoped that this year's theme of "Environmental and Climate Literacy" would help in creating awareness about protecting nature and natural resources.

According to the Earth Day Network, a global environmental movement, April 22 marks the anniversary of the birth of the modern environment movement in 1970.

Also, hundreds of volunteers, including students and officials of the US embassy, were out on the streets here to promote air quality awareness among people of the national capital and conducted a survey.

As part of the Earth Day activities, the US embassy, in cooperation with programme partner Clean Air Asia, organised a two-day campaign "Better Air, Better Earth" to promote air quality awareness.

The campaign involved volunteers from the embassies of the US, Sweden, Spain, the High Commission of Canada and Clean Air Asia's Youth Clean Air Network (YCan), who were posted at various locations here to record PM 2.5 levels and take a perception survey.

The campaign would continue on Sunday when the volunteers would record people's perception of air pollution in the city.

"We are proud to support Clean Air Asia's efforts to raise awareness about air quality in India. Projects like these are at the heart of this year's Earth Day theme — environmental literacy," Richard Pinkham, Director of Programmes, New Delhi American Centre, said.

Manaswi Singha, a student of Delhi University, and Nishant, an engineering student of Delhi Technological University, who were conducting the survey, said that they chose to be a part of the campaign as they wanted to create awareness and understand the real cause of pollution.

Also, NGOs, Bombay Natural History Society (BNHS) and Wildlife SOS organised a Snake Awareness Workshop. The aim of the workshop was "to promote wildlife wakefulness among public and to mitigate the effects of wildlife human conflict".

During the workshop, the team of Wildlife SOS demonstrated how snakes play a key role in the functioning of the entire ecosystem.

Also, there was a campaign to create awareness among the masses to save water.

"Eat less meat, opt for carpooling and unplug unused electronic devices — do your bit and make a huge difference to saving Earth," suggested Google's Earth Day doodle.

The doodle followed the story of a fox, who dreamt about an Earth that had been polluted and adversely affected by climate change.

Doing these small things could go a long way to help save the only known planet in the universe that harbours life, it said.

"Whatever you do today, we hope you're able to take a moment to savour and cherish this boundless, stunning Earth that we inhabit," Google said in a statement.

At an estimated 4.543 billion years of age, the Earth is also the densest planet in the solar system and the largest of the four terrestrial planets.