The rains have finally hit Sikkim, and, the reprieve of sun-baked days notwithstanding, are hitting us hard. There is nothing new in that, some might say, but there is more to it than is obvious. The long bouts of sunny weather followed by heavy rain point towards a worrying trend that has been in play for the past many years. While the total amount of rainfall the state receives annually has more or less remained the same, the number of days when it rains has decreased. Another, and perhaps larger, matter of concern has been the steady rise is minimum temperatures. At 0.07 degree Celsius per year, Sikkim probably has the highest rate of increase in minimum temperatures in the entire country according to the Meteorological Department, Gangtok.
The fall in the number of rainy days as against normal overall amount of rain, means there is an increase in the intensity of the downpours. This does not augur well for a state which has forever been battling landslides and bodes ill for the agricultural sector as well.
“Bursts of heavy rainfall are not conducive to farming since there is more surface water run-off. Water does not percolate into the soil properly as compared to light rainfall over a long period of time which allows for enough water to be absorbed by the soil on which the crops can survive for longer periods. Heavy rain also erodes the top soil which is the most important factor for plant growth,” explains Joint Director, Indian Council for Agricultural Research [ICAR], Dr. RK Awasthe. He adds that this change in the rainfall pattern of Sikkim has been noticeable since 2004.
On the effect of such change in the rainfall pattern on the agriculture of Sikkim, Dr Awasthe says that it is difficult to assess any change because of a lack of base data to compare present conditions against.
“We, along with the rest of the world, have woken up a little late. Since we do not have proper data of the past, we are now conducting experiments by simulating similar conditions in the Plant Growth Cell at our Centre to find out what changes have taken place. Studies have also been started now and it will take a while before we can come to any conclusion,” he shares.
Meteorology In-Charge, Gangtok, Dr GN Raha, highlights that rainfall and weather conditions in the state remain normal. From 01 to 27 August, the state received 1,606 mm rain which is 18% above normal [1,366 mm]. In comparison to the country which has received 17% less rainfall this year, conditions in the State are normal, he states, adding however that in the long term, the number of rainy days has decreased.
“The mean minimum temperature has been increasing at the rate of 0.07 degree Celsius in Sikkim every year which is probably the highest in the country and this is a matter of concern. A rise in minimum temperatures is more worrying than a rise in maximum temperatures because it has wide ranging effects. Climate change, apart from various other factors, is responsible for this,” says Dr Raha.
The impact of this rise in minimum temperatures has already started manifesting in Sikkim according to Dr Awasthe. “We are seeing newer insects like the Tea Mosquito Bug which wasn't here says 5 years ago. Plants like Hibiscus [Jawakusum] and Lantana which grow in warmer regions can be seen even at higher altitudes here. Lantana is spreading very fast across the state which is not good because it wipes out everything else around it,” he says.
Lantana is a tropical plant considered an invasive weed and its spread is aided by the characteristic of their leaves, which are somewhat poisonous to most animals, while their fruit is a delicacy for many birds which distribute the seeds. Biological control of lantanas has been attempted, without robust success in certain places like in Australia where about 30 insects were introduced in an attempt to control the spread of lantanas.
According to Dr Awasthe, pest and disease management will be one of the major challenges for agriculture in Sikkim in the coming years especially with the state set to go fully organic by 2015. The rise in temperatures will affect a change in the host-pest range where the vegetation and crops will be altered along with the pests and diseases that they attract. Further, warmer climes together with high precipitation, provide the best conditions for growth of pests and diseases. Erratic and untimely rainfall makes moisture preservation another important challenge, he adds.
Considering the El Niño phenomenon that is to occur this year, Sikkim seems to have been spared any dramatic weather event as such. 'El Niño' begins as a giant pool of warm water swelling in the eastern tropical Pacific Ocean, that sets off a chain reaction of weather events around the world – some devastating and some beneficial. In contrast, the rest of the country, as predicted, has had scanty rainfall due to El Niño.
While there is no denying that agriculture is a major stakeholder in the climate change movement, what comes through from the interactions with experts and concerned department heads is the feeling of helplessness against this global phenomena. What is needed are mitigation and adaptation strategies along with research and studies into the impact of what climate change means for Sikkim.
