Cigarettes packages in China will soon carry a health warning covering nearly a third of the surface. But some experts say not even an oversized warning will stem demand in what has become the world's largest consumer of cigarettes.

China became the 77th and final signatory to ratify the WHO's Framework Convention on Tobacco Control this week. The convention calls on nations to urge their citizens to curb tobacco use through measures such as public education about tobacco-related illnesses.

According to China's state media Wednesday, harsher warnings will cover approximately 30 percent of the cigarette package. The warnings might include pictures and text describing health problems, such as lung cancer and heart failure, associated with smoking.

Dr. Daniel Ho, an expert on tobacco related problems at Hong Kong University, says more explicit warnings are a good public health decision.

"In some countries in Asia they have already put up the signs and pictures illustrating the harmful effect of smoking on the cigarette pack, and studies have shown that such measures are effective in reducing the smoking preference and to remind people of the harm of smoking," he said.

Dr. Ho says China has a staggering number of smokers - approximately 350 million people, or about one-quarter of the country's 1.2 billion population.

China's state media estimates 2,000 people die of tobacco related illness everyday. That figure could rise to 8,000 by 2050, if the current rate of people taking up smoking continues. Dr. Ho says the number of smokers typically increases as a country develops.

He points to Hong Kong, a city that has enjoyed rapid economic development since the end of World War II. The number of smokers peaked in the 1980s, but Dr. Ho predicts that it will be many years before the number of smokers in China reaches a plateau.

"In Hong Kong, for example, about 20 years ago cigarette smoking was a lot higher than it is now," explained Dr. Ho. "Now only about 15 percent of Hong Kong people smoke. But now in China, about 60 percent of men and less than five percent of women in China smoke? and that is still increasing and we would expect the prevalence won't peak until 30 years later."

By signing the WHO Framework Convention on Tobacco Control, China has also agreed to higher prices and taxes on tobacco products. But China's lawmaking body, the National People's Congress, must still pass the measures.