Heat-up in Sikkim despite green cover - Snowfall delayed by a month in hills

Snow covered Zuluk in East Sikkim last week

Vivek Chhetri and Nirmal Mangar, TT, Darjeeling, Jan. 9: The delay in snowfall in the upper reaches of Sikkim and Darjeeling by over a month may be a damper to snow-chasing tourists and local people, but may reflect either changing weather patterns or special circumstances this year, scientists say.

Sikkim has experienced the highest increase in annual average minimum temperature across India's states, the India Meteorological Department (IMD) has documented - a finding that has puzzled sections of environmental scientists because nearly half the state is under forest cover.

The area under forest cover in Sikkim rose from 44 per cent in 1993 to 47 per cent in 2013, while the national average is 21 per cent.

While low temperatures are not the only criterion for snowfall, the increase in minimum temperature can affect snowfall patterns, a weather scientist said. But the delayed snow in the upper reaches this year may also be linked to a weak moisture-laden storm from the west this year, he said.

While the upper reaches of Sikkim such as Gurudongmar (17,000ft), Nathu-la (14,000ft) and Chhangu Lake (13,500ft) and Sandakphu (12,000ft) in Darjeeling usually receive snowfall from November end, these areas received snowfall only in December end this year.

A 2013 IMD report had found that the average minimum temperature had increased the highest - 0.07°C per year - for Sikkim, followed by Arunachal Pradesh, Bihar, Delhi, Gujarat, Manipur, Tamil Nadu and Tripura during the study period.

The IMD study examined trends of around 60 years, from 1951 to 2010, relying on 282 surface meteorological stations that had continuous temperature records since 1951.

The average minimum temperature in Gangtok during January is now around 3°C.

"The cause and effect of these temperature changes are still unclear," a senior IMD scientist who requested not to be named, told The Telegraph, on the phone from Delhi.

The IMD official said future studies would be aimed at understanding the causes driving these temperature trends.

Environmentalists say they are surprised by the temperature changes given Sikkim's large forest cover.

"The only explanation I can think of is the increase in human activity," said Bharat Prakash Rai, the general secretary of the Federation of Societies for Environment Protection.

Rai and others have also observed that some species of rhododendrons have started flowering a month in advance. Rhododendrons usually flower from February but in areas near Sandakphu the trees have started flowering in January.

"We've been seeing such advance flowering for several years. A study on the cause underlying these trends needs to be conducted now," Rai said.

Sanjay Gurung, a senior citizen from Darjeeling, said: "Over the years, one can feel that the chill is dropping even in Darjeeling town. The last major snowfall witnessed in the town was in 2007 and this year, the days are relatively warm with clear blue skies."

Gopal Pradhan, a senior scientist and environmentalist with the Sikkim State Pollution Control Board, said: "In other states, deforestation contributes to the rise in minimum temperature, but in Sikkim the forest cover has increased and so has the average minimum temperature. I think growing population, vehicle pollution, urbanisation, industrialisation and global warming - they are all contributing in their own ways."

Advisory

The Sikkim North district administration has issued an advisory to vehicles travelling towards Gurudongmar Lake and Yumthang Valley asking them to use anti-skid chains to avoid road accidents.

The advisory was posted on the Facebook page of subdivisional magistrate of Tshungthang recently.

According to Border Roads Organisation sources, Lachung, Lachen, Yumthang and Gurudongmar were under approximately 20cm of snow in the first week of January.