In what could be a major concern for the region, the three main rivers of Punjab — Ravi, Beas and Sutlej — are getting less water since the annual air temperature has shown a considerable increase in the northwestern Himalaya (NWH) region in the last century. The problem assumed alarming proportions in the last two decades.
A research by Dr MR Bhutiyani, division head of Chandigarh-based Hazard Assessment and Forecasting Division of Snow and Avalanche Study Establishment (SASE) showed that the annual air temperature has shown an increase of about 1.10°C during this period in all three main stations — Shimla, Srinagar and leh in the northwestern Himalaya (NWH), Bhutiyani, who has been doing his research on the issue for the last several years, said warming effect is particularly significant during the winter season.
Winter temperature has shown an elevated rate of increase (1.40°C/100 years) than the monsoon temperature (0.60°C/100 years), due to rapid increase in both, the maximum as well as minimum temperatures, with the maximum increasing much more rapidly. “Rising winter air temperatures have caused decreasing snowfall component in total winter precipitation on the windward side of the Pirpanjal Range.
The studies also indicate reduced duration of winter by about two weeks in the last three decades. Role of anthropogenic activities influencing climate change in last three decades cannot be ruled out” Bhutiyani told The Pioneer about his study. Bhutiyani said that an episode of comparatively higher (above-average) temperatures from 1876 to 1892 was followed by three more periods of temperature variation. Below-average mean air temperature persisted from 1893 to 1939 indicating a cooler episode, followed by a period of relatively stable/average temperatures till around 1969.
The periods from 1969 to 1990 and from 1991 till 2006 are characterised by above-normal temperatures indicating warmer episodes. Temperature seems to have increased at markedly different rates during these two periods. The rate of increase appears to be highest since 1991 as compared to the period prior to 1991, indicating unusual warming in last two decades. Anthropogenic forcing is the climate change brought about by human activity.
Excessive burning of fossil fuels and changes in land use patterns have increased concentration of gases like CO2, methane, nitrous oxide, etc. in the atmosphere and have caused the greenhouse effect. It is the anthropogenic forcing which has been a matter of great concern. It is believed to be responsible for significant climactic changes that have occurred all over the world in the recent past, with alarming consequences for the mankind,added Bhutiyani.
He said that in layman language we may say that during the last four decade, due to increase in the temperature, the discharge of glaciers is reducing gradually; hence the supply of water to the Ravi, Beas and Sutlej rivers is also being reduced as compared to the previous period. It may create a serious problem in the coming years, added Bhutiyani.
“We have already informed to the concerned authorities about this factual report, now it is up to them to take a call”, the scholar said. He said that due to climate change, the effect of this gradual change can be seen in the hilly areas. “The vegetation is also migrating from the lower hills to the higher peaks of the mountains to get the required cool atmosphere due to increase in the temperature at lower hills”, said Bhutiyani.