▲In 1989, the esteemed actress founded the environmental group Mothers and Others, which informs the public about the danger of pesticides and other chemicals in food. Streep drew inspiration for the project after reading a report about pesticides on fruits and vegetables published by the Natural Resources Defense Council.

▲Since the 1980s, Streep has been an outspoken advocate of conscious consumption, and fights for greater food safety. She explained to environmental magazine OnEarth, "I was very conscious to try to do the right thing and do well by our kids."

▲In 2009, Timberlake created Mirimichi, the world’s most eco-friendly golf course, in Memphis. The award-winning facility is famous for its environmental education programs, water conservation, and wildlife sanctuaries.

▲Because Timberlake has used his platform to enforce environmental issues and has made a conscious effort to limit his carbon footprint while on tour, he was awarded the Environmental Association’s Future Award in 2011.

▲In 2005, Clooney spearheaded the Oil Change campaign, which pushes against America’s dependence on foreign oil. In his private life, the Oscar-winning actor also drives an electric car and regularly speaks up about climate change.

▲Clooney fully joined the fight against fossil fuels after starring in the film 'Syriana' in 2005. He told Time magazine: "If you're doing a movie about oil consumption and corruption, you can't just talk the talk. You gotta walk the walk."

▲Olivia Wilde is a proud proponent of various social issues such as women's and workers' rights. She has also avidly spoken up about ethical consumerism and avoiding "fast fashion."

▲In an interview with Mashable, Wilde explained that shopping awareness is "eating more consciously because we’re wondering where things are coming from. In terms of fashion, it's wondering how something was made, what was used to make it, who made it and what can I do to be less wasteful when I get rid of it."

▲Besides being a champion for women's rights, the actress is also an outspoken eco-advocate. Hayek is a board member of Global Green USA. She also co-hosted the Bid to Save the Earth auction, which raises funds to provide clean drinking water to those in need.

▲The actress told Eluxe magazine that she became involved in environmental causes because of her daughter. Hayek said: "I get a bigger fear of what kind of world she’s going to live in. Is she going to run out of water? What kind of water is she going to drink? It’s really scary and it’s not that far away if we don’t do something about it."

▲The actor has worked with the nonprofit PlantMed, which operates alongside indigenous Amazonian groups in Peru and Ecuador to source natural treatments and cures for chronic illnesses.

▲The actress adopted a sustainable lifestyle after learning about traditional indigenous ways of life. She was inspired by what she learned and began to use herbal medicine, shop locally, and buy used clothing.

▲Woodley is also an outspoken advocate for environmental causes such as herbalism and climate change. She was awarded by the Environmental Media Association for her work during the protests against the Dakota Access Pipeline in 2016.

▲The organization helps Congolese cocoa farmers negotiate mutually beneficial deals with massive corporations such as Starbucks or Theo Chocolates. It also works to create policy changes with the US that favor developing countries.

▲In 2014, the 'Pretty Woman' actress narrated Conservation International’s documentary 'Nature Is Calling.' Julia Roberts also became a spokesperson for Earth Biofuels in 2006, which promotes using sustainable fuel alternatives such as biodiesel and ethanol.

▲She told Conservation International: "I realized that I wasn't doing enough to protect the planet. People need nature and of course, I want my children to have the best possible opportunity in life. I also realized how important it was for me to raise them to be conscientious people that are aware of their impact on the Earth."

▲The 'Avengers' actor co-founded The Solutions Project, which aims to lean the US towards using 100% renewable energy with wind and solar power. He has also spoken out against the use of toxic chemicals that negatively impact marine life.

▲Ruffalo narrated and produced the documentary 'Dear President Obama: The Clean Energy Revolution Is Now' (2016), which critiques the expansion of natural gas drilling under his presidency. He also participated in the protests against the Dakota Access Pipeline.

▲The 'Black Swan' actress is the face of many important causes, and climate change is certainly one of them. Natalie Portman became a vegetarian when she was just eight years old, and then switched to veganism in 2009 after reading the book 'Eating Animals' by Jonathan Safran.

▲She also regularly used her platform to speak out against the long-term use of oil and coal. She is a recipient of the Ongoing Commitment Award from the Environmental Media Association.

▲Aside from starring in 'The Vampire Diaries' TV series, this actor has made a name for himself in the environmentalist community. In 2010, he aided the cleanup after the Deepwater Horizon oil spill in the Gulf of Mexico.

▲The veteran actor and founder of the Sundance Film Festival has championed environmental issues for decades. Indeed, he has been a trustee of the National Resources Defense Council since the early 1970s.

▲Along with his wife Keely Shaye Smith, Brosnan has worked with several environmental organizations including the International Fund for Animal Welfare, and is listed as a trustee of the Sea Shepherd Conservation Society.

▲In 2004, Brosnan was named "Best-dressed Environmentalist" by the Sustainable Style Foundation. He's pictured looking suitably dapper at the headquarters of the United States Environmental Protection Agency.

▲The musician often appears in concert as a way of further promoting the plight of the Earth and the dangers of climate change. He's pictured here at a Live Earth gig in New York City.

▲The former Police front man is a passionate advocate of human rights and environmental issues. Together with his wife, Trudie Styler, and Raoni Metuktire, a leader of the indigenous tribe Kayapo in Brazil, Sting founded the Rainforest Fund to help save the rain forests and the indigenous people there.

▲The Australian actress works with SolarAid, a charity that seeks to eliminate the kerosene lamp from Africa. Solar energy is close to her heart: she and husband Andrew Upton personally installed the roof of the Sydney Theatre Company with almost 2,000 solar panels.

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In 2014, Blanchett took part in the Green Carpet Challenge, an initiative to raise the public profile of sustainable fashion. She's an honorary life member of the Australian Conservation Foundation.

▲In 2012, the actor launched the Robert Redford Conservancy to help educate university students about sustainability. Robert Redford has in the past also taken the platform at the UN to speak about climate change.

▲The Leonardo DiCaprio Foundation supports several global initiatives to protect vulnerable ecosystems, communities, and wildlife. DiCaprio also sits on the council for various environmental organizations, including Global Green USA and the Natural Resources Defense Council.

▲He has also produced two films to promote environmentalist issues. In 2007, DiCaprio released his feature-length documentary 'The 11th Hour,' in which 50 of the world’s climate change experts detail solutions to help save the planet. 'Before the Flood' (2016) explores the impact of global warming.

▲Arguably the "king" of environmentalism, Al Gore changed the game in 2006 with the groundbreaking climate change documentary 'An Inconvenient Truth.' The former US Vice President won an Academy Award and many other international accolades for the film.

▲During his 2000 presidential campaign, Gore, a Nobel Peace Prize winner, made environmental issues the core of his political campaign. His follow-up 2017 film, 'An Inconvenient Sequel: Truth to Power,' addresses the progress made to tackle the problem of climate change and Gore's global efforts to persuade governmental leaders to invest in renewable energy, culminating in the landmark signing of 2016's Paris Agreement.

▲The organization brings awareness to deforestation and the healing powers of Amazonian plant medicine.

▲In 2010, Affleck founded the Eastern Congo Initiative, which is a nonprofit that works "with and for the people of Eastern Congo" on issues of economic and social development. The group uses sustainable agricultural practices to help the productivity of small farmers in the region and create economic stability.

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The actor has vigorously opposed factory farming and GMOs, both online and in interviews. His organization, the Ian Somerhalder Foundation, works to promote issues about the environment and animal rights.

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Rather recently, iconic actress Jane Fonda was at the forefront of protests around climate change, leading to her arrest on numerous occasions. And what's been a constant at each of those protests? Her now famous red coat. It really has taken on a life of its own, with Fonda even saying it's the last piece of clothing she will ever buy. Inspired by Greta Thunberg, the actress also wants to fight consumerism.

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Climate change is one of the hottest topics in the world, and the entertainment industry is voicing its concerns big time. Actors, musicians, and more are using their celebrity status to actively raise public awareness about environmental issues and the threat of global warming.

Click through this gallery to discover the celebs who are helping to save the planet.