Earth Day, that global holiday that celebrates the Earth, urges conservation and protection, and champions climate change action, got plenty of star-studded attention this year.

In the past, Earth Day, also known as Arbor day and observed on April 22nd, has passed quietly, with a small contribution from the Arbor Day Foundation to encourage people to plant trees and do better for their environment. But lately, especially with climate change being a topic of hot contention, more people have started to take notice.

While activists like Greta Thunberg helping to champion changes to climate laws and bring attention to ways we can all help the Earth, celebrities are also doing their part to help spread awareness.

Related: This Is How Greta Thunberg Trolled Donald Trump On His Last Day

Instagram was a favorite this year for helping stars share their thoughts and celebrations for Earth Day. Zac Efron shared personal pictures and posts about his travels, including some from his Netflix series Down to Earth, commenting on how blessed he's been to learn about all the things people are doing to protect the Earth and cultivate sustainable living practices.

Actress Jennifer Garner traded her movie premiere wardrobe for coveralls in a recent post to thank her family, and everyone who chooses to purchase organic, biodynamically grown produce.

Reese Witherspoon interacted with fans by urging them to partner with her to protect our home, and asked how others are reaching out to do just that.

Drew Barrymore had a special reason to celebrate, wishing her daughter, Frankie, a lovely Earth Day Birthday and sending her fans a sweet message.

Ellen DeGeneres celebrated the holiday by giving her audience members Earth friendly gifts: Gift cards abounded from companies like H&M and Whole Foods.

Related: Jimmy Kimmel Viewers Troll Ellen DeGeneres Over Alleged Staff Abuse

She also executive produced and narrated a film for Discovery+ this year, titled Endangered for earth day celebrations.

Meanwhile, Kate Hudson put her money where her mouth is. Her Flabletics brand donated $25K to ConservationOrg to help protect 1K acres of tropical forest.

Melissa Joan Hart reminded everyone this Earth Day that the easiest way to care for the earth is to Reduce, Reuse and Recycle, to help replenish and restore nature to its former glory.

She also put up a fantastic quote about sacrificing today for generations to come tomorrow. “The ultimate test of a man’s conscience may be his willingness to sacrifice something today for future generations whose words of thanks will not be heard” - Gaylord Nelson

Related: Jennifer Garner’s ‘Goth Vibes’ With Kat Dennings Are Making Fans LOL

Earth Day might not be on everyone's holiday radar, because it's not a federal holiday where government and federal buildings, banks, etc. shut down for the day. But it might just be one of the most important days to help others remember that the earth has a lifespan too, and if people don't pull together to make our home better, there's no telling how long it'll last.

Next: Zac Efron’s ‘New Face’ Sparks Debate On Male Beauty Standards