Sunday is Earth Day 2018, and more than one billion people across the globe are expected to celebrate with environmentally friendly events. But what exactly is Earth Day? Here's what you need to know: >> Read more trending news 1. When did Earth Day start? The first Earth Day celebration took place 48 years ago, in 1970, after a devastating oil spill in America brought environmental issues to the forefront of public consciousness. According to the Environmental Protection Agency, 22 million people across the country came out in support of environmental reform. 'That day left a permanent impact on the politics of America,' Gaylord Nelson wrote in the April 1980 edition of the EPA Journal. 'It forcibly thrust the issue of environmental quality and resources conservation into the political dialogue of the nation. 'It showed political and opinion leadership of the country that the people cared, that they were ready for political action, that the politicians had better get ready, too. In short, Earth Day launched the environmental decade with a bang.' Since then, celebrations have only grown. This year, organizers estimate more than one billion people in 192 countries will participate in events the world over. The day is celebrated each year on April 22. >> Target’s Earth Day car seat recycling program offers 20 percent off new car seat, stroller 2. Is there a theme for Earth Day 2018? This year, organizers are focusing on curbing plastic pollution. 'Our goals include ending single-use plastics, promoting alternatives to fossil fuel-based materials, promoting 100 percent recycling of plastics, corporate and government accountability and changing human behavior concerning plastics,' the Earth Day Network, which partners with tens of thousands of organizations in 192 countries to organize Earth Day events, said on its website. The organization also said it 'will educate millions of people about the health and other risks associated with the use and disposal of plastics, including pollution of our oceans, water, and wildlife, and about the growing body of evidence that decomposing plastics are creating serious global problems.' Read more here. >> Antarctica's ice retreating 5 times faster than normal, study reveals 3. How are people celebrating? In Tokyo, thousands of people will attend beach cleanups, concerts, art exhibits, classes and other events coordinated by the Green Room Festival, according to the Earth Day Network. In India's Karnataka state, a 'no plastic' event will feature workshops led by 'organizations that are champions of environmental sustainability in fields including electric vehicles, solar power and zero-waste living,' the network said. Cleanups also were scheduled in Palm Beach, Florida; New York; New Jersey and other locations across the United States and worldwide. Read more here. 4. What are businesses doing? Google marked Earth Day with a 'video doodle' featuring primatologist Jane Goodall. >> Click here to watch “It is so important in the world today that we feel hopeful and do our part to protect life on Earth,' Goodall said. 'I am hopeful that this Earth Day Google Doodle will live as a reminder for people across the globe that there is still so much in the world worth fighting for. So much that is beautiful, so many wonderful people working to reverse the harm, to help protect species and their environments. And there are so, so many young people, like those in JGI’s Roots & Shoots program, dedicated to making this a better world. With all of us working together, I am hopeful that it is not too late to turn things around, if we all do our part for this beautiful planet.” Read more about the doodle here. Apple also joined in on the celebrations, announcing on April 19 that 'for every device received at Apple stores and apple.com through the Apple GiveBack program from now through April 30, the company will make a donation to the nonprofit Conservation International.' In addition, Apple 'debuted Daisy, a robot that can more efficiently disassemble iPhone to recover valuable materials,' according to a company press release. “At Apple, we’re constantly working toward smart solutions to address climate change and conserve our planet’s precious resources,” Lisa Jackson, Apple’s vice president of environment, policy and social Initiatives, said in a statement. “In recognition of Earth Day, we are making it as simple as possible for our customers to recycle devices and do something good for the planet through Apple GiveBack. We’re also thrilled to introduce Daisy to the world, as she represents what’s possible when innovation and conservation meet.” Read more here. >> Tips for celebrating the 20th anniversary of Disney's Animal Kingdom 5. How can I get involved? There are multiple ways to get into the Earth Day spirit, from participating in a local event to changing your bills from paper to paperless. Here are some suggestions from the Earth Day Network: Urge your local elected officials or businesses to make a substantial tree planting commitment by starting a letter-writing campaign or online petition. Lead a recycling drive to collect as much plastic, metal, and glass as possible. Pick up trash at a local park or beach. Set up a screening of an environmentally themed movie. Consider supplementing the screening with a speaker who can lead a Q&A following the film.