When thinking of young people taking a stand against climate change, many of us will immediately think of Time's 2019 Person of the Year, Greta Thunberg. And with good reason! Thunberg and other young environmentally conscious heroes are giving us grown-ups a much-needed wake-up call – and a heavy dose of inspiration, too.

Today's young people are taking a stand for sustainability and making the world a better place for the rest of us. They know what's up. Now it's up to us to listen up.

Check out these incredible stories of environmentally conscious young people taking action to save the planet for generations to come.

Ryan's Recycling

In 2012, Ryan Hickman was just 3 years old, but he was about to go on an adventure that would change his life. That adventure? A trip to the rePlanet recycling center.

The following day he made a historic announcement to his dad. He proclaimed, "I'm going to pick up all of the bottles and cans from everyone in the neighborhood." With a goal to save money for college, Ryan began Ryan's Recycling Company.

Since that fateful day in 2012, Ryan Hickman – now 7 years old – has recycled over 100,000 pounds, which equates to over 750,000 bottles and cans... and those numbers are quickly rising.

With all of his success, Ryan can afford to do more than just save for college. In fact, he has so far raised over $11,000 for college and donated nearly $10,000 to the Pacific Marine Mammal Center.

His extraordinary efforts have brought him national recognition from the likes of ABC World News, Ellen Degeneres, and National Geographic. Ryan was even named a 2017 Young Wonder by CNN.

Little Miss Flint

Amariyanna "Mari" Copeny began her rise to environmental stardom when she was just 8 years old. In March 2016, Mari – who would come to be known as "Little Miss Flint" – wrote a letter to then-President Barack Obama asking him to do something about the water crisis in Flint, Michigan.

That letter inspired the President to go to Flint himself and speak about the crisis.

Since then, Mari has continued her activism for clean and safe water for all. She's appeared in promotional videos for climate change and has even begun her own hashtag – #WednesdaysForWater – to raise awareness for people around the world who don't have access to clean drinking water.

She hasn't forgotten about Flint, though. Since 2016, Mari has been consistently fundraising and has raised over half a million dollars, which has benefited over 25,000 children in Flint.

In the Summer of 2019, Mari partnered with a water filtration company. Together they are working to bring cutting-edge water filtration systems to the people of Flint and other communities around the United States suffering from unsafe water.

Ava's Lemonade

Ava Lewis began selling her lemonade outside of her mom's hair salon in Durham, North Carolina. From selling her cups of lemonade, Ava made enough money to go out and buy supplies for new mothers and babies in her community.

The following week, Ava and her mother dropped those supplies off at the Good Samaritan Inn, which serves about 130 women and children each night.

Oh, by the way – Ava is only 3 years old.

Ava's lemonade stand has been a huge success since that first day in front of the hair salon. Customers have gone from buying cups of lemonade to buying gallons, and Ava has been able to make an even bigger impact on her community.

She's become a local phenomenon and is easily recognizable when she's out and about in Durham. Her local fame has even earned her the nickname, "The Lemonade Baby."

Environmentally Conscious Little Heroes

These young heroes are making a huge splash in the world of philanthropy and sustainability. Plus, their selfless efforts show us that even the smallest among us can make a huge impact.

Not only will their efforts make the world a much better place, but also they are inspiring people of all ages to make small changes in their daily lives to do their part to help the planet and communities around the world.

Ryan, Mari, and Ava are astonishing individuals, but they're not the only ones out there.

In the comments below, tell us about the young heroes in your life who are making a difference in your community!