On June 4, Cheng and 17 of her fellow activists from around the world staged a raid on the Leiv Eiriksson oil rig, rented by Cairn Energy, to demand an oil spill response plan. They were detained, then deported. Cheng is now back in Hong Kong and remains undaunted.
"We decided to go directly to the rig," Cheng says. "We didn't really work out a plan. We simply rushed onto the rig and frantically looked for the captain's station. It might sound like an irrational act, but at that time, it was the most direct way to stop irresponsible oil drilling. Every moment matters."
Cairn Energy is a small company based in Britain. It specialises in exploring oil resources. Greenpeace says the company runs on a low budget, which makes it prone to possible oil leakage.
The oil rig's operation in Arctic waters near the North Atlantic islands has been approved by Greenland's government, but Greenpeace says the company lacks a proper oil spill response plan.
Before their raid, Greenpeace activists had phoned, written, faxed, and e-mailed to the company for a copy of it. They received no response, so finally, they decided to act.
Greenland police moved in by helicopter, arresting Cheng and other activists for trespassing and entering a security zone. They were taken to a prison in Nuuk, Greenland's capital, for 14 days. They stayed among local inmates and were then deported to Denmark.
Yet their arrest helped raise awareness in Greenland of the potential environmental impacts of oil drilling. "Most of Greenland's GDP [gross domestic product] is derived from the local fishing industry," Cheng says. "Greenlanders' well-being is extremely vulnerable to any environmental changes."
She calls the Arctic "a frontier of the environmental battle", as it remains relatively free of pollution.
Cairn, she charges, uses toxic chemicals, and its oil drilling operations run a high risk of spilling, especially near icebergs. Oil can accumulate in ice, hindering cleanup efforts and causing long-term damage to the environment.
"How blatant is that?" Cheng says. "Companies live off handsome profit margins by exploiting the environment, while innocent residents pay the price."
Cheng and her fellows are still facing legal action and may be required to travel to Greenland for a hearing. Yet they are now collecting signatures from the public against drilling in the Arctic.
Cheng urges young people in Hong Kong to think green, live green and act green. "Our carbon dioxide emission per capita is double the global average," she says, adding that you don't need to go to the Arctic to help save the planet.