'The global climate system doesn't look at where the carbon dioxide is coming from.'
'It may be emitted by the US, but it will not remain above the US alone but covers the whole world.'
It is a reality that the Indian monsoon has become erratic and unpredictable in the last decade or so, resulting in floods, landslides and even droughts.
This unpredictability has had a huge impact on agriculture too affecting the livelihood of many.
And it is a well-known fact that climate change has a lot to do with this.
Dr Madhavan Nair Rajeevan, in his new book South Asian Summer Monsoon, written in collaboration with Parthasarathy Mukhopadhaya and Arindan Chakraborty, discusses how the monsoon pattern has changed now.
After retiring as the secretary at the Ministry of earth sciences, Dr Rajeevan is currently Vice-Chancellor at the Atria University in Bengaluru.
"Trump doesn't believe that climate change is happening though the US is experiencing extreme weather events," Dr Rajeevan tells Shobha Warrier/Rediff.com
Is it because climate in India especially the monsoon, more so the south-west monsoon, has changed its pattern drastically in the last decade or so, that you decided to study the Indian monsoon in the last five decades and write South Asian Summer Monsoon?
Actually the book was pending for many years as we do not have a comprehensive book on the monsoon.
Many people have written about the Asian monsoon which covered the East Asian monsoon. But there was no comprehensive textbook specifically on the South Asian monsoon.
I decided to write this book mainly with students in mind, students who want to learn about monsoons.
We have done lots of research, and plenty of research papers have come in the last 50 years. We have analysed all the data that is available in the last 50 years to see how the monsoon has changed its pattern.
And the book is basically an accumulation of all the research papers with all the updated information.
It is a general textbook covering all the aspects right from the basics to using technology to predict monsoons, and not one on climate change alone. But there is a chapter on the impact of climate change on the Indian monsoon.
Even though we meant it as a textbook for university students, it can be useful for even policymakers.
What were the interesting facts you found out as you were going through data from the last 50 years?
In fact, we have 150 years of data on the Indian monsoon.
When you analyse this long-term data, you will see that it is a very stable system.
Yes, there are year-to-year variations like, in some years, there will be a drought while in some years, you experience excessive rain.
In some years, the monsoon will be poor, and in some years, it will be more.
Though the monsoon rainfall is a robust system, an important factor that is happening in the last 50 years is that the frequency of heavy rainfall has increased.
It is like this; it rains for a few days, then it stops. And after a gap, it rains again. This, we call is the dry spell between two rain spells., a good wet spell, then a dry spell followed by a good wet spell.
What has happened is, while the frequency of heavy rainfall is increasing, the length of the dry spell also is increasing. The dry spell gets prolonged for many days unlike in the past.
So, while the toral amount of rainfall remains the same, the days in which it rains has reduced.
It means, when it rains, it rains very, very, heavily.
Earlier in Kerala, it used to rain the whole day during the south-west monsoon season, and it never was heavy. But now, it is almost like a cloud burst...
Exactly. Not just in Kerala, in many other parts also, the rain pattern has changed.
Earlier, it used to rain 24 hours a day.
Now, you get heavy rains like 100mm, 120mm, etc for a few hours, and this has become very common.
The characteristics of monsoon has changed.
What could be the reason? Global warming?
There is no doubt about it. It is purely attributed to global warming.
More temperature means more moisture and when the clouds form, it rains more.
So, everything is related to global warming.
The Gadgil Committee report of 1988 warned about the impact of the exploitation of the Western Ghats through deforestation and mining on the south west monsoon.... Kerala is experiencing everything he had warned about.
Very true. The Western Ghats have a very prominent role in the monsoon circulation, and the monsoon rainfall along the West Coast.
In India, maximum rainfall happens in two areas, the West Coast and North East India and both are hilly regions. So, the mountains and the forests play an important role in the monsoon rainfall. They are the important components of monsoon circulation.
Destroying forests is not a good idea at all. Forests support the natural climate system by providing enough moisture. Basically, it is a source of water vapour.
When you destroy forests, the source of water vapour is lost.
Even the characteristics of the soil condition also will change.
In effect, it adversely affects the rainfall.
It happened in the Amazon Forests also. When they removed the forest, it had an immediate impact on the local rainfall.
For local rainfall, forests are very important. The regions close to the forests get more rainfall. But it may not really help the whole monsoon region.
So, you should not touch the forests at all.
If you make any artificial modification of the Western Ghats, the effects will be seen immediately on the monsoon rainfall.
What do you think will be the impact of global warming on the South Asian monsoon?
There is no doubt that global warming is happening. Even if global warming is not happening, the monsoon can vary due to natural variabilities. But global warming can add more variability to the variation.
Now we see that the effects of global warming much exceeds the natural variabilities.
So, global warming is an overriding factor in monsoon variation now. This is going to continue in future too as global warming is not going to come down.
We also see that the sufferers of climate change whether it is floods, landslide or forest fire, are the poor...
Yes, climate change impacts the poor, the women and children more.
Those who get affected are not the big people who burn the fossil fuel.
Those who have serious impacts are the poor people South Asia, Africa, etc who don't burn much fossil fuel.
The global climate system doesn't look at where the carbon dioxide is coming from. It is a uniformly distributed gas. It may be emitted by the US, but it will not remain above the US alone but covers the whole world. So, its impact on different climate systems is different.
The US, the UK and Europe may be emitting carbon dioxide more, but the impact will be seen somewhere else, and the sufferers are the poor in Africa, India, Pakistan, Bangladesh, etc.
So, mitigation becomes all the more important....
Of course, mitigation is very important. That's why the Paris Agreement talks about how to control it.
Now the US has backed out of the Paris Agreement, because Trump doesn't believe in climate change.
And they are one of the major emitters, second or third in the world, and if they don't have any control over it, you will see serious effect on climate change.
Do you think the recent forest fires, cyclones, flash floods and scorching summer seen in the US and Europe will make them rethink about their strategy?
Yes, the US and Europe have started experiencing this kind of extreme weather events. The US saw forest fires, flash floods and cyclones.
France had a serious heat wave.
These extreme weather events are part of global warming.
Europe realises that it's a dangerous thing and they are committed. You need political commitment.
But Trump doesn't believe that climate change is happening though the US is also experiencing extreme weather events. The US is already very prone for hurricanes. So, the impact will be more in their coastal region.

On the other hand, India is very committed.
The problem is, you cannot say that you stop everything and remain a poor country. After all, all the developing countries including India are aspiring countries.
We are not saying, don't develop. Countries like India have to develop.
They have to develop but what we have to adopt is, how to develop the country without harming the nature. That's what we call as sustainable development.
Every country has to be responsible and make sure its development is sustainable and doesn't harm others.
Are you optimistic about the way the world is going to look at environment and be responsible?
I don't want to be pessimistic.
I am optimistic but I have my concerns because things are not going well.
This is not the way we want to contain climate change.
Feature Presentation: Ashish Narsale/Rediff.com