SCIENCE TO SAVE THE HIMALAYAS

HE western Himalayas— a region naturally vulnerable to rain-induced disasters—are facing the impact of climate change at an unprecedented scale.

- YASPAL SUNDRIYAL

To the common man, these are natural disasters; to the scientific community, it is a challenge to determine how the losses may be reduced.

Why are torrential rain and extreme climatic events increasing in the region? The reasons are well understood—human activity-induced imbalance in greenhouse gases is the leading cause. Temperature in Himalayan regions at an altitude of above 4,000 metres has been increasing at about 0.5°C a decade. Low-pressure zones are forming frequently, into which waves of not only southwest monsoon clouds are rushing, but those borne from the Bay of Bengal (southeast) and westerly winds too, making it a triple junction susceptible to high-intensity rainfalls.

Recent research from the Birbal Sahni Institute of Palaeosciences and Mizoram University is alarming and defines the challenge to save the Himalayas. Using rings on tree crosssections as a proxy, BSIP researchers found that the trend of monsoon rainfall has been decreasing over the past 500 years, while the incidence of extreme events is increasing. These results are alarming for the entire Himalayas in general, and the Uttarakhand Himalayas in particular.