Standing in his home office in Bethesda, Maryland, meteorologist Jagadish Shukla gestured at the high-resolution satellite map of India hung on the wall. It shows every groove of his home country’s geological landscape in vivid detail.
He swept his hand over the deep blue of the Arabian Sea and the bits of bright-white snow atop the Himalayas, launching into an impassioned mini-lecture on ocean temperature.
“The trick is how to find predictable components in a chaotic system,” Shukla told me.
Shukla, who is 81, spends his days finding patterns, building models and defining boundaries to make sense of Earth’s climate. He’s come a long way from his childhood village in northern India, where he spent his summers playing outside and praying for rain.
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The most anticipated season of each year was the annual monsoon, he writes in his memoir “A Billion Butterflies: A Life in Climate and Chaos Theory.” Monsoons follow India’s hottest period and last for months, providing both relief from the sun and fertility for the land.
But the monsoon also can be a source of suffering. Some years the rain brings intense flooding, while in others there’s too little for a good harvest – or worst of all, drought and famine.
This unpredictability planted an idea in Shukla’s mind: What if we could know? If the village had a monsoon forecast, farmers could plan for wetter years or brace themselves for drought.
In 1970, a nervous but optimistic 26-year-old Shukla arrived in Boston to pursue his doctorate at MIT. His goal: find a way to predict the Indian monsoon’s seasonal impact.
At the time, weather forecasters relied heavily on “initial conditions” – how volatile factors such as temperature, pressure, wind or jet stream today might affect the weather tomorrow. As a result, meteorologists generally believed that predicting the weather beyond 10 days was a hopeless pursuit.
Soon after arriving at MIT, Shukla learned about the “butterfly effect,” coined by renowned meteorologist Edward Lorenz. Lorenz observed that even the tiniest changes in initial weather conditions – something as small as a butterfly flapping its wings – could make an entire system chaotic over time.
“The idea is that if you change just one decimal point in your initial condition, you will get a different forecast after 10 days,” Shukla said.
Lorenz’s work made many scientists skeptical about whether seasonal predictability was worth focusing time or research on. But Shukla’s felt sure that – at least for the monsoon – there was knowledge to be gleaned from the chaos.
“He was constantly seeing the glass half-full and that we should keep looking, whereas the scientific community was saying that you’re lucky to get anything out of that glass,” said Timothy DelSole, an atmospheric and climate science professor at George Mason University who worked closely with Shukla.
Then came the breakthrough. While daily weather is driven by volatile initial conditions, seasonal averages are shaped by something else, “boundary conditions” such as ocean temperature, soil moisture, snow cover and vegetation. And these boundary conditions are a source of predictability.
“He was the one who really cared, who took those ideas and developed them and convinced other people,” said David Straus, a climate dynamics professor at George Mason University who worked with Shukla. “Shukla had a really outsize role in saying, ‘Look, all these little pieces of evidence in the past are there, we can use them together.’”
In paper after paper, Shukla explored the interactions between Earth’s surface and atmosphere – not just for the monsoon but in weather across the world. He founded the Center for Ocean-Land-Atmosphere (COLA) at the University of Maryland, one of the first research groups dedicated to studying these interactions. COLA is now affiliated with George Mason University.
The ultimate proof of predictability came from Shukla’s “billion butterfly” experiment.
“This question kept gnawing at me,” he said. “People had already started believing seasonal predictability, but I had not written a paper exactly using the language of Lorenz.”
Shukla’s team ran simulations in which they dramatically changed the initial conditions – the metaphoric flutter of billions of Lorenz’s butterflies – while keeping the boundary conditions fixed. Despite the day-to-day instability, the seasonal outcomes remained consistent. It was the origin of the phrase “predictability in the midst of chaos,” which became the title of Shukla’s bellwether paper, published in the journal Science in 1998.
“The result was stark,” said James Kinter, current director of COLA. “The other papers that had come before that were all just little bricks in the wall, they’re all just pieces. But the ’98 paper was able to synthesize all that.”
As Shukla deepened his work on dynamic seasonal prediction, a new scientific field was emerging: climate change. Throughout the 1970s and ’80s, Shukla’s colleagues repeatedly asked if he would turn his attention to global warming. Shukla always declined.
He’s quick to reject the label of skeptic but admits he “wasn’t convinced yet” about global warming. He worried the claim of human-induced climate change was too bold, too early.
“I thought that was very dangerous for our field because suppose it gets delayed 10 years, then scientists will be blamed,” Shukla said. “I was worried that we don’t have enough data to prove it really convincingly.”
Finally, in 2004, he accepted an invitation to serve on the United Nation’s Intergovernmental Panel on Climate Change (IPCC) to work on its fourth comprehensive assessment of the climate. Coordinating lead author of the report David Randall said that Shukla was chosen for more than just his scientific background.
“Shukla, I think, is effective in both oral and written communication,” Randall said. “He’s a very persuasive guy in a kind of unaggressive way.”
As Shukla listened to hundreds of experts, read comprehensive papers on climate change and saw the results from sophisticated models worldwide, he moved from ambivalence to alarm. He became convinced that global warming was real, rapid and human-induced.
In the bombshell IPCC report, published in 2007, Shukla and his fellow scientists declared that the “warming of the climate system is unequivocal” and identified “discernible human influences.” That year, the panel received the Nobel Peace Prize for its work, along with former vice president Al Gore, with Shukla sharing in the honor.
“I cannot accept something simply on faith and belief,” Shukla said. “The reason 2007 got the Peace Prize was because it was the first time our model said, ‘Oh, it’s now beyond the uncertainty.’”
Shukla believed the IPCC report would be a moment of reckoning. Instead, the report provoked forceful backlash from the fossil fuel industry. Companies began establishing coalitions and campaigns to sow the seeds of doubt about global warming and lobbied politicians to stall climate regulation.
In 2015, frustrated by the power of these fossil fuel corporations, Shukla wrote a letter to President Barack Obama, co-signed by dozens of his colleagues, urging the president to investigate energy companies for misinforming the public about climate change.
“Many people say: ‘Oh, you’re a scientist. You shouldn’t say anything about it.’ I don’t agree. We’re scientists, but we’re also citizens of this society,” Shukla said.
“I counseled against it at the beginning,” Kinter said. “I didn’t think it was a good idea because it would draw this huge spotlight of attention from bad actors. But he felt very strongly that it needed to be done.”
In response, House Republicans accused Shukla’s nonprofit of partisan political activity and demanded an investigation. The National Science Foundation’s inspector general launched a formal probe.
“We knew that it was David and Goliath. We knew that this was a going up against a very powerful and well-funded machine,” Kinter said. “But it was above and beyond what any of us expected.”
It was one of the most “cruel and chaotic” times of Shukla’s life. He shielded his colleagues from the details of the investigation at work, but back home was constant stress. Shukla was interrogated about the ins and outs of expense reports, handed over hundreds of documents and says he needed pills to sleep through the night.
“I already had heard about things like this, but when I experienced it firsthand, I knew how vicious it could be,” Shukla said. “Before that, we used to just laugh and ignore all of it. Now, how can you laugh.”
After turning over thousands of records and receipts, the investigation came up empty.
Shukla squeezed a small plush ball on his desk, a blue sphere with green, continent-shaped blobs. Even scientists who dedicate their lives to predictability, he told me, must accept that outside of the lab, chaos reigns. Still, Shukla somehow always seems to be hurtling himself into the center of a storm. He set down the ball and looked straight at me.
“It’s a small price to pay to defend the integrity of climate science,” he said. “If we don’t defend it, who will?”