Dawa is also a butterfly researcher at the region's plateau biology academy.

He was paying attention to the environment long before the establishment of his organization.

As a biologist, he often needs to work in fields and Cai has donated much time, money and energy to environmental protection.

The Han and Tibetan make a team to keep Lhasa clean.

"The latest activity is to provide environmental protection training at schools, including protecting plants, recycling trash and banning plastics. We hope students adopt the awareness of environmental protection. Once these students enter society, it will become habit and common sense to protect the environment," Cai said, adding that a trial started in June in a vocational school in Lhasa and will be applied to other schools if successful.

As a native of Anhui province, 50-year-old Cai has lived in Lhasa for more than 20 years and sees the city as another hometown.

Cai runs a factory producing environmental protection bags.

"When I was kid, the environment in my hometown was great. But now it is no longer good. I gained direct experience of the importance of environmental protection in Tibet," Cai said.

"If Tibet's environment is a piece of white paper, once it has become dirty, it is extremely hard to turn it clean again," he said. "It is not only a business, but a career".