Heat waves are set to intensify and stretch longer, Madhavan Nair Rajeevan, meteorologist and secretary of the Union ministry of earth sciences, tells Nitin Sethi in an interview. Edited excerpts.
Tell us about your findings in the new research paper you have co-authored on heat waves in India.
We did an analysis of observational data of temperatures. We derived an index for heat waves. We analysed it over different parts of the country. We found that the frequency of heat waves is increasing in the key April-June season. We found that frequency is increasing – that means the number of heat waves. Duration of the heat waves – the total number of days during which heat waves occur – is increasing. And, the maximum duration of heat waves is also increasing. When a heat wave comes it normally persists for 4-5 days. That too is set to increase. Earlier we used to have an average 4 days of heat waves, now it is 7 days.
We tried to understand why it is happening. Some years there are no heat waves and some years there are more. We found that there are two forces – EL Nino and another is the Indian ocean (sea surface temperatures). The year after El Nino we normally have more heat waves. Also Indian Ocean is a major controlling factor. It is not a regional or localised phenomenon. It is a large scale global pattern. The good news is, therefore, it is theoretically predictable. A local phenomenon is more difficult to predict.
Our models will be able to predict four to five days in advance that a heat wave is coming.
Will we able to narrow it down to what specific regions may face?
Yes, exactly. May not be possible to do it at district level but region-wise and few states we can identify, such as central India and north-west region. One or two days before the heat wave we can identify with little more precision about region. We are trying to do it this year. This year we first issued an alert that the whole season would be above normal. That was based on our climate model predictions. There also we said the frequency of heat waves could be more compared to earlier years. That is happening now.
I told you that El Nino and Indian Ocean are the two important factors. Future climate change projections show that frequency of El Nino will increase with increase in greenhouse gas emissions. So that can lead to more heat waves. Then, if you take all the oceans, Indian Ocean is warming at the highest rate. This warming will continue in the future. This is a very serious issue. Warming from Indian Ocean at large scale and higher frequency of severe EL Nino events is increasing. Put together that means heat waves are going to be increasing. It will be a very severe serious issue in coming years.
The aridity we saw this year, which led to the drought we are seeing this year. Was it because of less rainfall in winters or was there more to it?
The characteristics of our rainfall is such that it doesn’t rain every day of the 100-120 monsoon days. It rains only a few days. Even in a particular day it rains only a few hours not all 24 hours. So if you calculate the hours it rains, in most of the places, half of the total rainfall of a season comes in only 15-20 hours spread over the 120 odd monsoon days. So the intensity of our rain is very high. There is no time for that rainwater to go underground and it flows away as runoff and go aways.
And this trend of intensive short-spells rains is increasing with climate change?
Yes, that trend is increasing. So when it pours down it will pour heavily and it just flows off. Remaining rain comes after the big spells when temperature goes up. It comes in 1-2 mm and doesn’t contribute much as it evaporates. So if you really want the water to go down you have to store the water.
So rain-harvesting becomes all the more important?
It is very important for our country. We should not allow water to flow away.
So if am not mistaken, this also means greater challenges for farmers because the duration of rain and intensity of rain is going to change altering the windows for farming processes, such as sowing? Will it become difficult for farmers to understand when to sow, what etc?
Yes, exactly. See, if rainfall was distributed uniformly with 5 mm of rain every day it would have been very easy. But actually few hours it rains very heavily and remaining hours it rains very little. So our agriculture practice has to be tuned to this.
But this general trend of changes in monsoon have been available to us for few years for a while?
That’s true. At least for past four to five years I would say.
IITM Pune has been at the forefront of this work.
That is true.
How far have states been able to adapt to this information?
So far, my impression is, they have not been able to do so. Probably we are not able to communicate properly. So last time we did a lot of state level policies when the last UN IPCC report came - projections and impact studies for state levels were done. So far we have not done it for the new report.
You mean the Assessment Report 5 of the UN IPCC?
Yes. We are doing it. The IITM is preparing downscale products (state specific reports). So I understand the union environment ministry is doing some state-level policies now (on climate change). We would be able to expect what are the state level scenarios of climate change impacts and then they can plan for their adaptation.
You are a scientist and now also an administrator. What difficulties do you see in getting the government or states to respond to science? A general issue that impacts all countries of how governance and politics response to science.
In the earlier days it was very difficult to convince people, especially state governments, to agree that these things are changing. Now of course that understanding and awareness of climate change is much more. People are now aware. If you talk to a state government official now they understand and try to accommodate it in their administrative system. They try to do some kind of action. Say this time when we talked of heat waves several cities drew up their heat action plans. For example, Ahmedabad, Surat, Bhubhnewshwar, Nagpur did heat action plans.
But was this because these are traditionally places where administration and people have faced heat waves?
Yes in some ways. But say Delhi does not have a heat wave action plan. Rajasthan and UP do not have one. They can. When a heat wave warning is given by us what is the standing operating procedure that should be followed, they can develop one. Things like involving the health department, building shelters against heat waves for people who are on the roads.
The people who die in heat waves are those who are on the roads or in open going somewhere. They are not giving enough warning that it can really harm you.
So would it generally be people who are the poorest and marginal?
And, people who travel on the road. They are exposed to the Sun for many long hours. Last year in Andhra Pradesh more than 2,000 people died in heat waves. I was told many people who passed away were those who were travelling in a bus, for example. They did not have water to drink. They did not expect it. It was very harsh and they didn’t get to drink water and by the end of the journey they felt dizzy and many died. This kind of information system passing information through newspapers and radio telling people that when you go out be careful, use an umbrella, drink water – these kind of warnings should be given.
Your research paper says out of all the natural calamities, heat waves causes the largest number of deaths in India…
Yes, that is right. Cyclones lead to deaths but because our warnings are there people keep safer and the frequency of cyclones in India is not so high. But you can expect many heat waves in a year and they impact a much larger geographical area.
For heat waves you are bringing new understanding now. But for issues such as meteorological drought, agricultural drought, there is a large understanding that has already existed. Why do the states sometimes fail to respond in time?
Drought is not an instantaneous phenomenon. It persists for longer duration. So it’s not as if people are not aware that drought is happening. I don’t want to comment on why people are not doing it. But they can do it. Unfortunately we do not have a drought policy in this country. We should.
What would be the components of an ideal drought policy?
It can vary from place to place. So accordingly we have to them specifically for different parts. But my feeling is you can’t have one right away. One should start with dialogues and discussions how we want it and start writing some elements. In next two to three years we can have a drought policy.
You think it takes that long?
Yes, because India is not one homogeneous region and drought doesn’t understand boundaries. See then, till last year our ministry used to say drought. We stopped it because of these regional variations that have to be accounted for.
Yes, why did you stop calling it drought and instead announced ‘deficient rainfall’?
When we announce a drought it’s not necessary it is going to happen through-out the country. If we say drought, the impression comes out as if we have a drought situation all across the country. It is usually not so. Drought we used to define for research purpose say when it is less than 10% deficiency. We used to assume that that a higher deficiency will effect a larger area but the area each year of where the drought hits and how badly it does can be different in intensity and spread. Then, we are basically stepping in to an issue that is in the domain of state government. Frankly speaking declaring drought is not in our domain. It is for the governments to declare. We don’t want to jump in to kind of a declaration. We are not supposed to do that. We will say deficient monsoon, which can lead to a drought.
Are scientists at greater liberty to talk about these issues in some countries than in others?
We don’t have any difficulty or obstructions. But normally in India we find that we scientists don’t speak enough.
Don’t reach out to public…
Yes, don’t reach out to public. We do our research and assume that we are doing our work. This is not good. This is why our ministry is now thinking of reaching out more to people. For example I am meeting you. We have got on social media. We want people to know more. My personal feeling is we are doing a lot of good things which is not being adequately communicated to the people as yet. We are going to change that. Not just to tell that we are doing good things but so that our products are used and utilised more.
We are developing a strategy. Especially say our agro-met forecasts for food crops and farmers. They are very useful for people. But unfortunately we are reaching out to only about 20-30% of the farmers as of now.
How do you reach out to them?
Through different channels, radio, TV, newspapers and mobile. We find through third party assessments that the economic benefits of our agro-met forecasts are very high. So we can reach out to more. Similarly forecasts for our fisherfolk needs to spread. We are hardly reaching 10-15% fisherfolk at present. This shall be increased.
An issue with your announcement of average annual monsoon is people think a normal monsoon prediction means normal monsoon all across the country whereas there can be large variations. This year do we have some inkling of how the distribution will be?
We shall come out with the forecast by the next week or so where we shall be telling you about the four homogeneous regions. Unfortunately we cannot beyond that point at this moment.
You mean we don’t have the precision level to predict monsoon at smaller scales?
Yes. We are planning to do it next year. Using the models we use right now we can’t issue a state-specific forecast. But we have developed a dynamical, general circulation model which we are testing this year. Net year we shall be able to give state level predictions of rain. We shall give a spatial distribution of rainfall of which region will get more and which may get less. From there one can understand how the rains are going to be distributed.
What resolution levels can we expect for these monsoon projections next year?
At least at the state level to begin with by next year. Not beyond that. We know that is an urgent requirement. This year we are predicting an above normal monsoon but some pockets can have deficient rains. Every year it’s not the same so the spatial distribution of rain is very important. It may not be very accurate I should say. But we should get a good probability. Next monsoon we shall have this in place.
What is the other information that you would be able to bring out at a more micro level because people react to this kind of information only when it is very specific?
Next year our emphasis is to improve local city level forecast. At present we are going up to five days ahead but accuracy more than 2-3 days before rain is not so good at the moment. Sometimes people, in say towns like Delhi, want to know rain for the next hour that is not possible at the moment.
The other thrust area is going to be tourism. It’s a growing industry and there are many tourist destinations. So there we want to have a customised forecast. The people want different kind of forecasts based on the destinations. Say people going to Goa want to know whether they can go out to the sea and how the wind and Sun would be strong or not. Such kind of customisation we plan to do. Say someone going to Manali would like to know if it is snowing there or not.
Does it divert away from your resources and main focus?
It’s a tough job but once you customise and automate it will work on its own. We are developing some mobile applications for people to use these customised forecasts.
Do private forecasters give you a good challenge in creating such products that they are able to sell?
So far there has been no impact of the presence of private forecasters. That is my personal feeling. Whoever are the current private forecasters they are not meeting the challenge the way our ministry is – our work is much more. They can’t reach our level especially in terms of quality of science in the way we do. They basically download someone else’s forecast and giving to the people. Which everybody can do, even you can if you have a computer. What you need is a unique script and make a product. That is what they are doing. They don’t have the infrastructure or science. But let them do it, we always welcome more.
But I would like to say in none of other key countries such as US or UK, private entities don’t generate forecast which is different from the national agency. Say Accuweather is famous. They take the information from the US weather agency and customise it and add value to it and give it to the users. In the US there are no two forecasters.
You mean legally others are not allowed to forecast?
Yes, legally. Whatever US agency produces it gives it to the people through website. Their rule is that it should be given free of cost to people. So raw data is available. All you have to do is download it, customise it and give it to people. And, if you make money out of it, the government doesn’t bother. In the UK it happens the same way. Say BBC takes from the met office, customise it and give it to people but the actual forecast data is the same. In India this all is happening. They are downloading from someone else’s model and making their forecast. So last year we gave a deficient monsoon and they have a normal monsoon forecast and there was a conflict. That is not a good sign.
We are moving towards crop insurance systems, weather-based insurance systems etc. How mature is our information to facilitate this in terms of technology narrowed down to say the block level or even lower?
We are right now giving agromet forecast say from 130 agromet units across the country. That we are going to reach a higher level and cover 660 districts with an office in each district. From that we would be able to give a block level forecast. At present it’s at district level and we shall scale it up to the block level by 2019. So farmers will be able to expect that by 2019.