Chilling prediction
By Chen Zhiyong ( China Daily)
Updated: 2004-12-20 09:42

A snow sculpture of last year's International Ice and Snow Festival. [File photo]

Ice and snow sculpture fans in Harbin, Northeast China's Heilongjiang Province, are toiling harder this year to hasten their contributions for the upcoming annual International Ice and Snow Festival, which will open on January 5.

They are sharpening their tools in despair as this warm winter means local rivers are still dangerously thin, less than 0.3 metres in late November.

Ice could not be quarried until the first week of December this year, 10 days later than previous years.

Before heavy snow fell last week, festival workers were having to drill holes through the frozen river surface and draw water to make snow.

Not a surprise

According to Luo Yong, deputy director of the National Climate Centre, the China Meteorological Administration (CMA), the winter is defined as warm if its mean temperature exceeds average levels between 1961-1990.

Winter is not over yet, but Luo and many other meteorologists say they will not be surprised if it is the 19th so-called warm winter.

In fact, the United Nations' World Meteorological Organization (WMO) last week announced in its annual global climate report that 2004 is set to finish as the fourth-warmest since records began in 1861.

Since warm winters are the most evident phenomenon of global warming, the WMO warns that global warming is set to continue and bring with it an increase in extreme weather such as hurricanes and droughts.

The warming trend in China, which started in the 1980s, is noticeable in the eastern and western regions, according to the Analysis of Temperature Variation in the Last 100 Years in China report, by the CMA.

In the east, there are comparatively bigger temperature increases.

The year 1998 was the warmest in China on meteorological records, with 2002 and 2003 ranking second and third.

The most obvious warming-up is happening north of the Yellow River in China.

Multiple causes

The causes are complicated, and they have multi-fold factors, from the increase of greenhouse gases to the return of EL Nino, from deforestation to the continuation of global warming.

In the north, snow and ice melt much sooner.

As a result, there has been less light reflected in snow and ice and more heat has been absorbed by the soil - in turn leading to an increase in ground temperature in these regions.

Luo believes that the present El Nino phenomenon is certainly playing a role.

This is caused by abnormal temperature increases in tropical waters off the west coast of South America, which leads to global weather and climate anomalies.

It affects China every two to seven years.

World scientists have reached a consensus that greenhouse gas concentration is the main culprit of warming in the northern hemisphere.

Gases such as carbon dioxide, methane, water vapour and nitrous oxide have been proved to be primary factors.

"The emission of greenhouse gas resulting from human industrial and living activities has contributed directly to warming in the last 50 years," said Luo.

Environmental effect

Despite one or two advantages accompanying warmer winters, scientists are concentrating on the adverse effects.

Agriculture will probably be the most vulnerable sector, according to Luo.

Warmer weather could lead to a shortage of irrigation water and an increase in pests, most of which are usually killed off by the cold.

Luo estimates that three main crops in China - rice, wheat and corn - will suffer an output drop of 5-10 per cent by 2030.

Wang Jingguo, a professor with the Resources and Environment College of the China Agriculture University, says agricultural production will inevitably fall victim to the increasing number of natural phenomena such as drought and excessive rain.

Increased temperatures, especially at night, will affect the ability of plants to absorb nutrients, Wang said.

The higher temperatures will have an effect on human health.

Epidemics will not be killed off, for instance. According to a Xinhua News Agency report, the hospitals in Beijing and Tianjin have been crowded with patients with respiratory diseases this winter.

Scientists warn that the balance of nature that has been in place for millions of years may be in danger as global warming affects growing cycles of plants and the natural behaviour of animals.

"Animals and plants from the equator to the two poles all come under the influence of climate change," said Xie Yan, a research associate professor of ecology with the Institute of Zoology, Chinese Academy of Sciences (CAS).

Earlier springs will bring forward plant growth and the length of time animals hibernate.

Xie said that animals and plants constantly adjust their geographical distribution, life cycles, and migration habits to meet their physical, biological and climatic needs. In the process, their ability to survive decreases.

Bird watchers were disappointed this winter when they gathered at East Dongting Lake National Nature Reserve between December 3 and 5 to take part in the annual bird-watching contest, observing far fewer species of migratory birds compared with previous years, according to Xinhua.

The ornithologists said birds living in the north this year had no need to leave their habitats and migrate south.

Vegetation distribution may also respond to the warming trend, according to research by Luo and his colleagues.

Evergreens in cold temperate zones and grasslands in temperate zones may be on a noticeable decline by 2050.

Some Chinese tree species may even disappear altogether from some of their original habitats.

"These trees may move with the shift of temperature zones. But the temperature increases in the past and foreseeable decades are too drastic for the species to be able to adapt," Luo said.

Roof of the world

As the "starter" and "regulating area" for the climate of China and indeed of the eastern hemisphere, the Qinghai-Tibet Plateau has not escaped.

Over the last 10 years, temperatures have risen on the plateau, affecting glaciers.

Shen Yongping, a research fellow from the Cold and Arid Regions Environmental and Engineering Research Institute with CAS, has conducted an overview of retreating glaciers and their impact on the plateau, where there are more glaciers concentrated than anywhere else in the world.

Since the 1980s, the phenomenon of shrinking glaciers has become even more serious, according to Shen's research. All glaciers have shrunk except some large ones, especially since the 1990s.

"This dramatic change is the result of global warming," Shen said in his report.

He also pointed out that the retreat of glaciers has significant social and environmental impacts on the Qinghai-Tibet Plateau and surrounding regions. For instance, water supplies have decreased and wetlands retreated, threatening local wildlife and plants.

"Mitigating and adapting climate change and strengthening environment protection should be an important issue for all humans," he suggested.

The WWF (World Wide Fund for Nature) Climate Impact and Adaptation Project in the Qinghai-Tibetan Plateau, a partner of Shen's research institute, is working with his institute to work out a quantitative analysis on the relations between climate and water resource changes on the plateau.

"We will also step into the everyday lives of local residents and see what changes have occurred in their living habits as a result of climate change in recent years," said Qiao Liming, a research fellow from the WWF.