Today is International Women’s Day—the perfect excuse to highlight women around the world who are at the forefront of global environmental activism. In honor of the day, the Sierra Club’s Global Population and Environment Program and Sierra magazine have teamed up to host an eco-themed inspirational women social media contest.

• Now through the end of Women’s History Month (March 31), post a brief description (100 words or fewer) of your favorite female climate activist, eco-innovator, or outdoor adventurer, along with an explanation of why you chose her, on Facebook, Twitter, or Instagram.
• Don’t forget to use the hashtag #EnviroSHEroes to be considered in the competition.
• Judged for thematic relevance and clarity, the winner will receive a $50 online credit to the Sierra Club store.
• To see rules for entry click here.

Below are a few of the Global Population and Environment Program’s favorite eco-activists to inspire you:

Barbara Allen, Appalachian Trail hiker

"My conclusion was it was time to get out there and do something rather than sit around and be bored. So I closed my house, picked up my backpack, and started down the trail," said Barbara Allen in an interview with Knoxville News.

At 71 years old, Barbara became the oldest person to hike all 2,180 miles of the Appalachian Trail—the world's longest continuous footpath. And she did it solo. A retired public health worker, Allen didn't take up backpacking until she was 40 years old, but she’s making up for lost time.

Majora Carter, Founder, Sustainable South Bronx

"People wanted things like clean air, they wanted safe places for their kids to play where they wouldn't get hit by a truck. They wanted living wage jobs that didn't degrade the environment or kill them," Majora told CNN.

After leading a successful campaign against a planned waste facility in the South Bronx, Majora started an environmental justice nonprofit called Sustainable South Bronx. Majora also created the first new South Bronx waterfront park in over 60 years and an urban green-collar job training program for low-income community members. 

Wangari Maathai, Founder, Green Belt Movement and 2004 Nobel Peace Prize Laureate

“In a few decades, the relationship between the environment, resources and conflict may seem almost as obvious as the connection we see today between human rights, democracy and peace," says Wangari Maathai.

Wangari is the founder of the Green Belt Movement, an environmental grassroots organization focused on planting trees, environmental conservation, and women's rights. Since its inception in 1977, the organization has employed thousands of African women to plant over 40 million trees in Kenya. In 2004, Wangari became the first African woman to receive the Nobel Peace Prize for her “contribution to sustainable development, democracy, and peace."