Lin Hui always checks the small tag attached to clothing when he shops. He wants to see what kind of fabrics have been used.

"I prefer cotton clothing," explained the Beijing-based website editor. "I heard the production of polyester fabrics consumes too much oil and energy, which is not green."

Whether cotton fabric is truly greener, or more environmentally beneficial, than polyesters remains a subject of debate. But Lin's attitude is clear - he wants to reduce greenhouse gas emissions such as carbon dioxide.

"What I do may be trivial, but if everyone tries to live a low-carbon life, the result will be really big," said the 35-year-old.

Just this year, the low-carbon lifestyle, or Lifestyle of Health and Sustainability (LOHAS), suddenly became trendy in China, particularly among young urbanites, Lin said.

He works for ditan360.com, a non-profit, environmental website set up early this year. It provides all kinds of information about carbon offset,including government policies, tips on how to save energy and stories about celebrities "going green".

Catching on

Lin isn't the only one trying to improve China's environment by monitoring his carbon footprint.

On the popular social networking website, Douban (www.douban.com), established two years ago, more than a dozen environmental discussion groups have been set up.

In one group, called "Low Carbon Living", a carbon calculator is available online. People are using it to measure the amount of greenhouse gases they produce during certain activities. For example, a family of three consumes 3,000 kwh of electricity a year. They would need 22 trees to offset 2,355 kg of CO2.

"We are both the cause and victims of global warming, so it's everyone's responsibility to reduce carbon emission," reads a message posted on the group's home page.

Cyberspace information is translating into real life practice. Li Ling uses stairs more frequently than the elevator because she believes it keeps her fit while saving electricity.

"Sometimes I do want to use the elevator because I am tired or in a hurry. Afterwards, I remind myself about my carbon footprint. Then I may do something to offset it, for example, eating less meat, buying local products or taking public transportation," says the 24-year-old who lives in Shanghai.

Businesses are also beginning to pick up on the trend.

This Sept., Ctrip (www.ctrip.com), an airline ticket website, launched a service for clients to offset carbon dioxide released during each domestic plane trip they take.

For example, a single flight from Beijing to Shanghai can produce 222.4 kg of carbon dioxide. Three new trees should be planted to neutralize that carbon footprint.

Ctrip clients can exchange 5,000 credits, which are earned by flying15,000 kilometers, for one tree. It will be planted by volunteers of a Shanghai-based environmental group, "Roots and Shoots", in a desert area in north China's Inner Mongolia throughout April, 2009.

The service, the first of this kind in China, has received a positive response from passengers, according to Liu Hongbing, Ctrip's client service manager. In the past three months, 2,300 people exchanged credits for trees.

Another business, URBN, a boutique hotel in Shanghai, opened one year ago. It is also trying to capitalize on the increasing popularity of "going green." It is marketed as China's first carbon-neutral hotel.

Management says it tracks all energy consumed by the property- including staff commutes, food and beverage delivery and the energy used by each guest.

According to an agreement signed in May 2007, URBN will purchase carbon credits from Emissions Zero, an international intermediary which invests in local "green" energy development and emission reduction projects, to offset the hotel's carbon footprint.

URBN "hopes to set an example for other businesses and industries" in China, the fastest growing emitter of greenhouse gases, said Geneva Holden, business development manager.

She added, market response has been amazing because guests, mostly foreigners, like the idea of sustainability. But being environmentally friendly doesn't come cheap - staying in the hotel's penthouse room can cost 4,000 yuan (584 U.S. dollars) per night, almost a monthly salary for an office worker in Shanghai.

With expensive flights and hotel stays, most people in China can't afford the new trend of "going green."

That's where the government comes in.