Earth Day 2021: See the conservation projects working to Restore Our Earth | CNN

Captured as chicks and kept as status symbol pets in the gardens of hotels and private homes, Rwanda's gray crowned cranes were almost wiped out. Destruction of their habitat for agriculture added to the pressure and by 2012, only around 300 remained in the wild. Then, the majestic birds made a remarkable comeback thanks to local vet and conservationist Olivier Nsengimana, who spearheaded a program encouraging owners to surrender their pets. However, the cranes are still popular as pets, and under threat, in other African countries.

CNN

Eastern Egg Rock, an uninhabited seven-acre island six miles off the coast of Maine, was almost stripped of its Atlantic puffin population when hunters arrived in the late 19th century. Ornithologist Stephen Kress first encountered the seabirds over 50 years ago. On learning how threatened they are, he founded Project Puffin, an initiative to bring them back to the New England state. Thanks to Kress's efforts, nearly 200 breeding pairs now nest on the island.

Courtesy of Stephen Kress

<a href="https://edition.cnn.com/videos/tv/2021/03/19/patagonia-kristine-tompkins-spc-intl.cnn" target="_blank">Kristine Tompkins</a>, the former CEO of outdoor clothing company Patagonia, and her late husband Doug (co-founder of The North Face), set up Tompkins Conservation to create national parks in South America. Among its initiatives, it has created the vast <a href="https://edition.cnn.com/travel/article/ibera-national-park-argentina-new/index.html" target="_blank">Iberá National Park</a> in northeastern Argentina. It is home to some 4,000 species of plants and animals and when combined with the neighboring Iberá Provincial Park, covers 1.76 million acres -- making it the largest protected area in the country.<br />

Kristine Tompkins, the former CEO of outdoor clothing company Patagonia, and her late husband Doug (co-founder of The North Face), set up Tompkins Conservation to create national parks in South America. Among its initiatives, it has created the vast Iberá National Park in northeastern Argentina. It is home to some 4,000 species of plants and animals and when combined with the neighboring Iberá Provincial Park, covers 1.76 million acres -- making it the largest protected area in the country.

Harald von Radebrecht/imageBROKER RF/Getty Images

The arapaima is one of the largest freshwater fish in the world, capable of growing three meters long and weighing 200 kilograms. Overfishing led to population decline in the Amazon river basin, but two decades of work by conservationists and local communities has helped to establish well-managed fisheries -- saving the species and generating a sustainable income for local people.

Ricardo Oliveira/AFP/Getty Images

In the US, less than 15% of tallgrass prairie remains, most of it converted to farmland or lost to development. But as conservationists work to revive this iconic landscape, they have looked for help from an unusually hairy ally -- the bison. Up to 30 million bison once grazed on North America's wild grasslands but in the 20th century, they were nearly hunted out of existence. The Nature Conservancy has reintroduced more than 100 bison to Nachusa Grasslands in Illinois. Here, the natural behavior of these "ecosystem engineers" encourages the growth of wildflowers and helps native animal species to thrive.

Scott P. Yates/Rockford Register Star/AP

In 2001, husband and wife Charlie Burrell and Isabella Tree turned to nature to <a href="https://edition.cnn.com/2020/10/01/world/knepp-farm-rewilding-scn-cte-spc/index.html" target="_blank">restore their farm</a>, Knepp Estate, in the south of England. In "rewilding" the land, they allowed orderly arable fields to grow into tangled thickets and rugged pastures, and introduced large mammals including Tamworth pigs, Exmoor ponies, longhorn cattle and red, roe and fallow deer. The estate is now home to a wealth of biodiversity and has become a celebrated conservation success story.

In 2001, husband and wife Charlie Burrell and Isabella Tree turned to nature to restore their farm, Knepp Estate, in the south of England. In "rewilding" the land, they allowed orderly arable fields to grow into tangled thickets and rugged pastures, and introduced large mammals including Tamworth pigs, Exmoor ponies, longhorn cattle and red, roe and fallow deer. The estate is now home to a wealth of biodiversity and has become a celebrated conservation success story.

Charlie Burrell/Knepp Wildland

Waterlogged peatland makes up a fifth of the Scottish landscape and stores around 1.6 billion metric tons of carbon -- equivalent to more than 140 years of the country's greenhouse gas emissions. Around 80% of the peatland has been degraded by activities including heavy grazing and soil drainage for agriculture and forestry. The Peatland ACTION project is working to restore it, and 96 square miles of damaged peatland has been put on the road to recovery since 2012. Last year, the Scottish government announced it would invest £250 million ($320 million) in peatland restoration over the next 10 years, with the aim of restoring 965 square miles.

Edward Scott-Clarke/CNN

The olive ridley is the most abundant sea turtle, but it's also at risk of wildlife crime. Paso Pacifico, a US-based conservation group working in Central America, estimates that poachers destroy 90% of sea turtle nests on many of Central America's unprotected beaches, to sell the eggs into the illegal wildlife trade. Scientists at Paso Pacifico have developed decoy eggs fitted with a SIM card and GPS transmitter. These are placed in turtle nests to track stolen eggs and combat trafficking.

Hal Brindley

Three quarters of Costa Rica was once covered in lush rainforest, but excessive tree felling had destroyed between a third and a half of the forest by 1987. However, a government initiative that rewards farmers for practicing sustainable forestry and environmental protection has made Costa Rica the first tropical country to stop and reverse deforestation. With 60% of the land once again forested, the country is now home to about half a million plant and animal species.

Nell Lewis

The projects working to Restore Our Earth

CNN —

As the 21st century progresses, our fight to protect our planet is becoming increasingly urgent. Last year, wildfires blazing in the Arctic Circle set new emissions records, the Atlantic hurricane season raged stronger than ever before, and we came to the end of the hottest decade ever recorded.

A recent study that attempts to quantify environmental damage revealed that 97% of Earth’s land area may no longer be “ecologically intact,” resulting in reduced animal populations and loss of species.

The theme for this year’s Earth day is Restore Our Earth. As parts of the world start opening up after a year of Covid-induced lockdowns, the event’s organizers are putting out a call for action and highlighting the importance of combating environmental destruction.

“The theme rejects the notion that mitigation or adaptation are the only way to address climate change,” says Earth Day board member and leading environmental sociologist Dorceta E. Taylor.

“We cannot put off for tomorrow what we can do today,” she says. “Everyone must do their part.”

Scroll through the gallery above to see some incredible changemakers who are working to save and restore Earth’s rich biodiversity.