They discovered that chlorofluorocarbons (CFCs), which were common refrigerants at the time, were, in fact, potent greenhouse gases. While working at the US National Aeronautics and Space Administration (NASA)’s Langley Research Center in the 1970s, a young man from a village in Tamil Nadu discovered that one tonne of CFCs could have the same warming effect as 10,000 tonnes of carbon dioxide. His findings made the front page of The New York Times.

For half a century, his work has added important nuances to our understanding of how climate works. His research has formed the basis of international agreements. He has advised four Popes on climate change.

What does that mean for where we are today? Excerpts from an interview.

* Your life has been shaped by “productive accidents”: going to a school in Bangalore where you didn’t speak the language, taking an unfulfilling job in refrigeration, completely changing the focus of your PhD advisor. Do you think your successes came despite these obstacles, or because of them?

I had my early education in Tamil-medium schools in Trichy and Madurai. The Swedish Academy has a photo of me with my teacher, in tie and shirt – but no shoes. School provided shirt and tie. In those days (1950s) many parents could not buy shoes for their children.

During summer it was unbearable heat, we could not stay inside. There was no fan, no electricity. We couldn’t even go out. You cannot walk barefoot on burning ground. So the children used to play in the verandah.

Now imagine what happens in such places when the temperature rises by five or ten degrees. For me, this is the main issue of climate change. Now rich people like me emit heat-trapping pollutants, but the poor have to bear the brunt.

In 2014, I spoke to Pope Francis about this climate injustice in the parking lot of St. Peter’s Basilica. In his encyclical (or papal letter) published a year later, he described climate change as a moral sin.

A year later, I was on stage with the Dalai Lama for his 80th birthday celebration in California. After listening to me, he said: “Tell me, Dr. Ramanathan, how can you clean the external environment without cleaning the internal environment?” The Pope’s words and the Dalai Lama’s words were echoing in my ears until I incorporated social change as a key component of climate solutions in my work.

Coming back to education, it was in Tamil until my father was transferred to Bangalore. Suddenly, everything was in English. I didn’t understand a single word. I went from the top to the bottom of the class. Somehow – and this is where personality matters – I decided that my teachers didn’t know what they were talking about. That’s why I was failing. So, I started learning on my own.

More importantly, I lost my fear of the unknown. This gave me the opportunity to visit many areas, from the climate of Mars and Venus to the climate of Earth; From carbon dioxide as the sole warming agent, to CFCs, to pollution.

However, my grades were poor. I did not get admission in Indian Institute of Technology. I went to Annamalai University. After that I took a job in refrigeration, which I disliked. Customers were sending back new refrigerators within weeks because refrigerants, CFCs were leaking as the machines were not designed for Indian conditions. Those leaking CFCs stuck in my mind.

Once leaked, CFCs remain in the air for 50 to 100 years. Nature eliminates them by moving them into the stratosphere, where ultraviolet light breaks them down, releasing chlorine.

* That’s why the ozone layer was depleting…

Correct. Chlorine is highly reactive; In this way it kills germs and bleaches the clothes.

Anyway, bored, I set out to face the defining accident of my life. I joined the Indian Institute of Science (IISc) in Bengaluru, primarily as my ticket to the US.

The then Director assigned me the project of making an advanced instrument to measure temperature fluctuations in turbulent fluids. I made it in three years and it worked like magic.

It taught me what I was good at, as well as what my future challenge was: fundamental research.

I still remind all the youth: everyone is good at something. Take your time to find out what it is. Once you find it, you have found your career and you will excel.

Within a few months, I was invited to study for a PhD under the renowned Professor Robert Seuss at Stony Brook University in New York. I was dreaming of completing my PhD, getting a job at General Motors, buying a Chevy Impala and returning to my native Kumbakonam after becoming a hero.

* But your advisor changed the field to the atmospheres of Mars and Venus.

If you ask my friends, they’ll tell you I was depressed for a month, watching my dreams fade away. That accident… it pulled me into the climate.

But when I graduated, no one hired me. Who wanted to be an expert in the atmospheres of Mars and Venus? Then NASA was being accused of destroying the ozone layer, so they hired me to figure out how stratospheric ozone depletion would affect the climate.

Then I read a paper (1974) by two chemists – Mario Molina and F. Sherwood Rowland, who later won a Nobel for their work – which showed that CFCs destroy the ozone layer. This struck a chord.

Working in the evening, I calculated that one ton of CFCs warms the planet equivalent to 10,000 tons of CO2. I didn’t even tell NASA. I have just sent the paper. When it hit the front page of The New York Times, all was forgiven.

Till then CO2 was seen as the main problem. Later, a team led by me realized that non-CO2 gases like methane cause significant warming.

* In 1980, you published a seminal paper on warming…

With NASA engineers, I designed a satellite experiment to measure how the atmospheric envelope of gases traps heat.

People thought there was only one blanket. My CFC discovery catalyzed the discovery of a whole set of blankets for different gases like CFCs, hydrofluorocarbons or HFCs, methane, nitrous oxide, ozone. In 1985, I led an international team and showed that these non-CO2 gases were making significant contributions to warming, depending on the time frame. Suddenly, the problem was more serious than previously thought.

Working with meteorologist Roland Madden, we used observations to predict that by 2000, warming will exceed natural variability. Had done this.

* Now people, including governments, are saying that it is very difficult to cut emissions. There are people who argue that we should just put aerosols in there and geoengineer our way out of it. Is that a good idea?

no it’s not.

In an emergency, it can slow down the temperature rise. But aerosols dramatically reduce sunlight reaching the surface. Think of it like mirrors on a blanket: The mirrors reflect sunlight, but the dark particles absorb sunlight. So, brown clouds both reflect and trap heat, reducing what reaches the ground by three to ten times.

This affects the monsoon. Also, global warming makes the ocean warmer. Therefore, the Indian subcontinent is influenced by two opposing forces, making it difficult to predict.

Another problem with the approach is that we continue to release CO2 and other pollutants into the atmosphere while the monsoons dry up and the oceans become acidic.

Then, in 2018, working with two colleagues, I made a prediction that is unfortunately coming true: warming will exceed 1.5 degrees Celsius (above pre-industrial levels) by 2030.

At that time, the United Nations said: not until 2045. People said: There goes Ramanathan crying wolf.

But the planet’s temperature has crossed 1.5 degrees Celsius. By 2030, when it becomes permanent, extreme events will intensify.

* You have informed four Popes. Some say you were the primary architect of the science behind Laudato Si’, the subtitle of Pope Francis’ letter: On the Care of Our Common Home. Is faith more effective than science alone in bending the curve?

Trust is the key. I see this as the main – perhaps the only – hope.

* Why?

Climate resilience rests on three pillars: Mitigation to reduce pollution. Adaptation to inevitable changes. and social change so that we can survive and thrive.

Science-faith alliance is essential for social change. I also work with “Embracing Mother” Amma in Kerala and Amma in Vellore, one of whom has built a sustainable village and a school dedicated to educating girls in rural areas.

A tried-and-tested way of reaching people is through their faith leaders.

Many people think that climate change is happening somewhere else. It’s not touching them yet. We are lagging behind on mitigation. I worry that in about five years, maybe even sooner, we’ll see an ozone-hole moment on climate.

Going back to CFCs, chemists published their papers in 1974-75. The industry attacked him brutally. Ten years later, in 1985, the ozone hole appeared. Two years after that, we had the Montreal Protocol.

I think the ozone hole moment in the climate will come soon. Only then will we take action.

Over the next 10 years and beyond, climate change will enter our living rooms around the world.

* I ran out of water in my house. That’s how I got into it.

This says it all. Water and food will be my first focus for India. In the next five to fifteen years, India should focus on rural women and the urban poor.

On the positive side, we can still fix it.

But we cannot rely only on mitigation. We need to adapt now.

(Mridula Ramesh is a climate-tech investor and writer. She can be reached at tradeoffs@climateaction.net)