Although a Siberian cold front sent the mercury plunging as much as 8ºC in northern China last week, the country can expect another warm winter with El Nino returning, the Chinese National Meteorological Administration announced Tuesday.

Signs of El Nino were detected when atmospheric and surface water temperatures in the tropical Pacific Ocean began to surge abnormally in June and August.

The eastern part of the tropical Pacific has already entered El Nino conditions, with sustained high temperatures, and the phenomenon is expected to gather force in the coming months.

El Nino may bring China warmer winters, more rain in the south and drought in the north, as well as cooler summers in the northeast and fewer typhoons, according to Professor Ren Fuming of the National Meteorological Center.

However, he said that it is still too early to predict with accuracy the full impact of El Nino. Other climate factors, including snow accumulation on the Qinghai-Tibet Plateau, the subtropical high-pressure zone and the Indian Ocean current, might influence the country's weather patterns.

Occurring every four or five years, El Nino is an extreme disruption of the ocean-atmospheric system in the tropical Pacific and can cause weather-related disasters. On its last visit, from 1997 to 1998, El Nino brought global floods, drought and storms that caused US$20 billion in damage.

Whether El Nino pays a call or not, China has experienced 18 consecutive warm winters, attributable at least in part to global warming resulting from greenhouse gas emissions.

The average temperature last winter was 2 to 3ºC higher than the averages of earlier decades.

Warm winters exacerbate the long-term drought that has plagued northern China and may trigger more forest fires.

(China Daily November 3, 2004)