Though the big picture of the monsoon shows that the key crucial event for agriculture is stable, India will likely get more rainfall, and there will be spatial variability due to climate change, says Somnath Baidya Roy, The Rockefeller Foundation Climate Science and Technology Chair and Professor and Head, Centre for Atmospheric Science, IIT Delhi.
“As far as monsoon is concerned, there are two take-home messages. Monsoon is stable, and the big picture is not changing. There will be a little bit more rain because the atmosphere is warmer. As the atmosphere is warmer, there will be more extremes,” he told businessline in an online interaction.
Discussing the impact of climate change, Roy said right now, there is no evidence to say that a fundamental shift has occurred in the pattern of monsoon and rain.
“If you take a step back and look at the big picture and compare it with the kind of predictions people made after learning about climate change, Indian monsoons are stable,” said Roy.
Caution on conclusions
If people look at only the minute details within the big picture, he said, he would caution them not to look at these small things and draw conclusions. “The total amount of rainfall that India gets on average every year is a little bit variable. However, the total amount of rainfall has remarkably been stable over the years and data back it,” said the IIT Delhi professor.
However, there is a lot of spatio-temporal variability with some districts or tehsils getting more or less. “This year, the monsoon has set in early. Last year, it was late. But these are small changes.
Stating that the age-old Clausius-Clapeyron equation says that if air is warmer, it holds more water, Roy said climate change due to anthropogenic activity has made the world warmer. “Now, because the air is warm, it holds more moisture. Because there is more moisture, it will rain a little bit more,” he said.
More extremes
In the long run, the Rockefeller Foundation Climate Science and Technology Chair said, there would be an increase in monsoon rainfall and it will vary annually, besides spatial variability.
“The second thing is because the atmosphere is more energised now, temperatures are warm. When there is more energy in the environment, there is more turbulence. So we are seeing more of the extremes; that it is going to rain more and we will be getting more highs and more lows,” he said.
On the impact that weather change had on agriculture, Roy said Indian agriculture is not weather-driven as in Europe or the US.
In regions where there are weather extremes, there are problems. “We are seeing an increase in the extremes both ways, except in some minor regions. Also, because there is more water in the atmosphere, it will rain more. This is something we are seeing across the board,” he said.
Need for resilient system
There is evidence that over the last few years, there has been more rain during the post-monsoon season, but there is no evidence that this will be permanent and is here to stay. Therefore, the country should have an agricultural system that will be resilient to these changes, said Roy.
“The whole system, from financing, transportation, fertilizers and the entire ecosystem where farming is a major part, needs to be resilient towards handling extremes,” said Professor and Head, Centre for Atmospheric Science, IIT Delhi.
Roy, who put together a team to digitise data on agriculture, said India has made remarkable improvements in yield. “So, we are not that susceptible to the vagaries of nature as we were in the past generations. We have a robust system that can sustain itself,” he said, adding that Indians were getting a higher per capita amount of food than in the 1970s.
User-friendly forecasts
Though India is moving towards precision agriculture, he said there was a need for a robust weather forecasting system that is able to forecast the ups and downs of the extremes. “We lack a sub-seasonal scale forecasting. These forecasts not only help in our decision making, but this kind of data is very important for precision agriculture,” said Roy.
On the policies that need to be framed for these extremes, he said, “We need to take care of the most vulnerable. It is very important to support these kinds of farmers,” he said, adding that all farmers must be brought under an umbrella where information flows easily.
Stating that the India Meteorological Department is doing a good job by sending SMS text and other alerts to farmers, he said the department could enhance it further based on user needs.
He called for a two-way communication between farmers and meteorologists so that the former could get forecasts tailored to their needs.