Despite a transnational ban in 1989, every year at least 25,000 elephants are killed by poachers. Their tusks feed the hunger of ivory collectors, and supply the market for religious objects. At this rate, experts say the giant will likely become extinct in the wild by 2020.
"An elephant's tusk might make an exquisite work of art in your glass display cabinet, but it looks finer on an elephant's face where it naturally and rightfully belongs," says Celia, a student at True Light Girls' College. "The massacre must stop."
Outraged by ivory smuggling, the 14-year-old began a campaign to educate students about the plight of elephants, and urge the Convention on International Trade in Endangered Species (CITES) to impose a complete ban. In only five months, she has won the support of 26 schools and 58 green groups from countries from Hong Kong to Kenya and the US.
The young activist's campaign began with a letter to the South China Morning Post last October pleading for an end to the killing of the endangered species for its tusks. It caught the attention of Christian Pilard, founder of green group Eco-Sys Action, who helped set up her website and designed a poster.
Celia says elephants, the world's largest land animal, play a vital role in the ecosystem. Like bulldozers of nature, their footsteps create hollows that trap rainfall, and they dig wells with their tusks. Their movement through the forest opens new paths that act as firebreaks.
"When the elephant's numbers dwindle, it sets off a chain reaction that disturbs the livelihoods of other species reliant on their habitat-changing habits," says Celia.
When poachers kill mother elephants for their large tusks, their babies will likely follow them to the grave, says Celia. "Elephants are very affectionate animals which form close bonds with their family," she explains. "I've heard stories of grief-stricken young that starved to death beside their mother's decaying carcass. Even if they pull through, who will care for them and teach them crucial survival skills?"
The carnage in Africa may be far away, but it is fuelled by huge demand in Asia, especially China. Mainlanders are largely unaware of the crisis, says Celia.
A survey by the International Fund for Animal Welfare says 70 per cent of Chinese people think tusks - "elephant's teeth" in Chinese - fall out naturally grow back without causing any harm, so can be collected by traders. But the survey found that 80 per cent of people would reject ivory products, and not buy them again, if they knew elephants were being killed.
Hong Kong is a transit hub for the illegal trade. Between October and January, Hong Kong customs officers seized more than six tonnes of ivory - costing the lives of more than 850 elephants - from cargo ships apparently bound for the mainland.
Celia says law enforcement in Hong Kong isn't strict enough. "Smuggling ivory should be treated as harshly as smuggling drugs."
Celia hopes that basketball star Yao Ming can help to spread the message because she has tried in vain to reach out to schools on the mainland.
"He has always been a keen supporter of elephants," she says. "As a Chinese person with international influence, he could raise awareness in China and tell people not to buy ivory products."
Recently, she wrote to the general secretary of CITES, saying she hopes the killing will stop so the next generation will be able to see elephants on safari - not just in books and on TV.
Celia, who hopes to be an ecologist in future, is determined to ensure her campaign succeeds; she believes it will prove to be her life's work, like that of her idol, the British anthropologist Jane Goodall.