A popular Cantonese saying in Shenzhen about the weather became inapplicable this winter, after Shenzhen suffered an unseasonably warm winter.

Wei Shi Wuyue Zong, Hanyi Wu Ru Long , which roughly translates to "Don't replace your quilt with a thin one before eating dumplings during the Dragon Boat Festival," sounded irrelevant, and even silly after the city saw the warmest Chinese New Year in the past 38 years.

According to traditional Cantonese wisdom, temperatures exceeding 20 degrees Celsius arrive after the Dragon Boat Festival on the fifth day of the fifth lunar month, which falls on June 19 this year. The Summer Solstice, the 10th seasonal division point that marks the beginning of intense summer heat according to the lunar calendar, is three days after the Dragon Boat Festival.

The saying will probably have to be rephrased after sweltering warm weather arrived well before its time.

Hottest Spring Festival

The Shenzhen Observatory forecast Wednesday that the highest temperature Saturday, the Chinese New Year's Eve, will hit 25 degrees Celsius.

"It will be the hottest New Year's Eve since 1969," said a spokeswoman surnamed Li from the observatory. She said New Year's Day on Sunday will also be the third hottest within a decade, following 1999 and 2003.

The temperature on New Year's Day is expected to reach 26 degrees Celsius.

"However, sprinkles brought by a feeble northeast monsoon will be seen on the day," said Li.

The city's average annual temperature has risen 1.3 degrees Celsius in the past two decades. Global warming is taking its toll on the city and catching people unawares.

Climate change

Last year, the city's average annual temperature reached 23.4 degrees Celsius, a 0.2-degree increase from 2005.

"The just passed winter is the 21 consecutive warm winters since 1986 and temperatures are projected to increase in the coming decades," according to the Shenzhen Climate Bulletin 2006 released by the city's observatory in late January.

"Temperatures between October and December are 2.5 degrees Celsius higher than the average score in past years, and last October was the hottest October since 1952, when the city starts its temperature records," the report said.

The hottest day in 2006 was July 25, when 37 degrees Celsius was recorded across the city. This extremely hot weather lasted for eight days from July 18 to 25.

The observatory said rising temperatures lead to increasingly unusual weather patterns, such as more frequent storms in the summer.

Last year, Shenzhen had only 1,624 hours of sunshine, 312 hours less than the average in the past few decades, due to a unusually long rainy season. In June, 21 days saw rain.

Strong haze follows soon after the rainy season. At least 55 hazy days recorded in October and November. In comparison, there were 773 hazy days during the 1990s, while only three were recorded during the 1970s.

The humidity also reached a record low of 24 percent Nov. 11 last year due to the heat and haze.

But the fallout from rising temperatures is not restricted to weather changes alone.

Huang Jingji, director of the Shenzhen Observatory, said the dangers caused by climate change have not yet been adequately addressed by the authorities.

"The city and the Pearl River Delta region urgently needs more in-depth research on how we can adapt to the unavoidable aspects of climate change," he said.

Potential damage

Global warming has already caused the world's oceans to warm and expand, inducing a rise in sea level.

According to an eight-year study conducted by 100 scientists since 1993, the sea level near Guangdong will have risen 30 centimeters by 2030 because of climate change.

Coastal defenses in the region will be inadequate, roads and railways will be damaged by higher temperatures and flooding, and freshwater supplies - already stretched - will come under threat, it said.

Eventually, the rising waters could submerge land inhabited by people, forcing them to move. This includes Shenzhen, a coastal city.

Huang Zhenguo, head researcher of the eight-year project, who was earlier with the Guangzhou Institute of Geography under the Chinese Academy of Sciences' Guangzhou Branch, said that coastal areas in the province, including Shenzhen, had recorded a 6-millimeter rise in the sea level since 1990. Meanwhile, Guangdong has seen 1.5 millimeters of sedimentation annually in land across the province.

"Sea levels will raise some 30 centimeters within two decades under strong greenhouse effects, which means 1 million people in the province have to be evacuated," he said.

"These rises in sea levels can increase the salinity of freshwater throughout the province and cause coastal lands to be washed under the ocean. Warmer water may encourage tropical cyclones and changing wave patterns could produce more tidal waves and strong beach erosion on the coasts," he said.

This will also seriously threaten a city's sewage system. At least one month in a year, the city has to rely on pumps to discharge water as its outfalls are only 1.2 meters higher than the sea level.

According to Huang's research, all dams created for flood control must be reinforced as the tremendous floods that come once a century may now come every 30 years. The capacity of the pumps needs to be increased and more floodgates are needed. He estimates this will cost the province some 9 billion yuan (US$1.17 billion).

Greenhouse effect

Increasing temperatures could also lead to drought, shortages of water and electric power and low agricultural production. Strong haze following extremely hot weather could lead to closure of local airports and expressways, affecting transportation, logistics and travel industries.

In 2004, the average visibility within Shenzhen dropped to 11 kilometers and the number of traffic accidents greatly increased.

To ordinary Shenzheners, it also means more health concerns.

The most obvious health effect is directly related to the heat itself. With an increase in heat waves, there will be more people suffering from heatstroke, heart attacks and other ailments aggravated by the heat.

To deal with extreme hot weather, the municipal government enacted a law in 2005, requiring work be stopped when temperature exceeds 40 degrees Celsius.

When the temperature reaches 38 degrees Celsius, a maximum of four hours of work will be permitted. Hot weather also causes smoke particles and noxious gases to linger in the air and accelerate chemical reactions that generate other pollutants. This leads to an increase in respiratory diseases like bronchitis and asthma.

Nationwide impact

Qin Dahe, director of the China Meteorological Administration, told a press conference in Beijing on Monday that global warming had made extreme weather - such as high temperatures, drought and hurricanes - more common in China.

"It's too early to say categorically that China is experiencing another 'warm winter' this year, but the world's fourth-largest economy is definitely suffering the impact of global warming," a senior meteorological official said Tuesday.

The temperature in Beijing reached 10.8 degrees Celsius last Sunday, the first day of spring according to China's lunar calendar, and surged to 16 degrees Monday, the highest temperature at this time of year in the past 167 years.

Beijing has experienced 20 consecutive "warm winters" - where average temperatures from December to February are at least 0.5 degrees Celsius higher than the average - since 1986.

Qin said that, under the influence of human activity, the global climate had been warming since 1750, as evidenced by higher average air and ocean temperatures, the widespread melting of snow and ice and rising sea levels.

Qin said that meteorological disasters cause direct economic losses of 200 to 300 billion yuan in China annually, which is equivalent to 2 to 5 percent of China's gross domestic product.

Editor: Yan