On World Environment day, we travel to the Qinghai-Tibet Plateau, where the world’s highest-flying birds, the bar-headed geese are breeding. Those who are protecting them, are a group of non-government conservationists. It represents a growing trend in China's conservation effort. Tao Yuan has their story.

This now looks like a desert. Tudam's sheep don't have enough grass to eat, so his family has to frequently move to find more grasslands. But the area used to be a different landscape.

GAYER TUDAM DAMBA YANGTZE RIVER HEADWATERS ECOLOGICAL CONSERVATION STATION "When I was little, the grass was so much better. When we rode on a horse, it used to reach up to our feet. Now the desertification is terrible."

TAO YUAN QINGHAI "The Qinghai-Tibet Plateau is dubbed 'Asia's Water Tower'. It's where the continent's great rivers come from, and where many consider as one of the world's last 'pure lands'. Now, the grasslands are disappearing, the glaciers melting. The 'roof of the world' is turning into a scene of a climate change catastrophe."

So Tudam has turned into a conservationist to protect his homeland. The Yangtze River source region is a breeding ground for the bar-headed geese. Setting up a satellite-equipped watch station in a no-man zone, Tudam's team represents a shift in China's conservation strategy. His boss is leading the effort. Yang Xin built China's first non-government protection station some thirty years ago. A humble start, which drew world attention to the reckless poaching of the Tibetan antelopes. Now, NGOs like Yang's GreenRiver are taking on more in China's conservation efforts.

YANG XIN FOUNDER, GREENRIVER "The government is realizing that it has limited resources and manpower to carry out protection work, and they are enlisting the help of grass-root organizations. The benefit of that is we know our area. We can dedicate all our effort to a relatively small region."

All their effort now goes into protecting the world's highest-flying birds.

GAYER TUDAM DAMBA YANGTZE RIVER HEADWATERS ECOLOGICAL CONSERVATION STATION "The bar-headed geese can cross the Himalayas in eight hours. Their difficult journey is very touching to me."

It's also a difficult journey for Tudam's team. It is hard fundraising for the equipment and painstaking measures to put them in place. At 4,600 meters above sea level, these volunteers who run the station have abandoned modern lifestyles.

WANG RERE VOLUNTEER, GREENRIVER "I like it here. Therefore I feel a responsibility."

HU YUANYE VOLUNTEER, GREENRIVER "Yes it's tough work. But I think what we do here is so meaningful."

For Tudam, his work means something more.

GAYER TUDAM DAMBA YANGTZE RIVER HEADWATERS ECOLOGICAL CONSERVATION STATION "I built this tower. I used to pick the eggs of these birds for food. My mother made me build this as an atonement."

Now he's a destroyer-turned-guardian. These ducklings are now taking their first dip. A scene that makes all the effort worthwhile.