The weather has a talent for showing up uninvited—soaking your shoes, frying your lawn, or hijacking your weekend plans. We grumble, adjust, and refresh the weather apps expecting the skies to obey the latest prediction, never questioning what it takes to make one.  But in A Billion Butterflies: A Life in Climate and Chaos Theory, Jagadish Shukla reveals the journey behind every sunny icon and storm warning. He traces his journey from a flood-prone village in India to the halls of climate research, proving that predicting the future—at least the meteorological kind—requires more than just luck.

Born in a small village in India, Shukla grew up under the looming uncertainty of the monsoon. The weather was always in charge, and so much so that it has been called the country’s real finance minister. A season of rain could mean a good harvest, or total loss. That kind of uncertainty wasn’t just frustrating, it was personal, which seeded a question in his mind: Can weather be predicted? What follows in the book is his journey from a barefoot schoolboy to a globally recognised climate scientist who helped transform the understanding of climate systems.

Shukla played a key role in modernising India’s weather forecasting capabilities. After urging the secretary of science and technology to invest in advanced computational tools, he became a driving force behind India’s acquisition of a Cray X-MP/14 supercomputer through a landmark agreement with the United States. Given the sensitive nature of the technology, Shukla was initially the only person authorised to access it. Over time, he and his team trained Indian scientists to operate the system, run predictive models, and generate routine forecasts—laying the foundation for India’s first fully operational, modern numerical weather prediction system.

Among Shukla’s most significant accomplishments was helping India build the capacity to predict extreme weather events. He demonstrated that large-scale phenomena like El Niño and monsoons could be predicted weeks or even months in advance by using coupled ocean-atmosphere models. But the success of early El Niño forecasts had unintended consequences. The accuracy of those initial predictions created a false sense of closure, leading to a sharp decline in funding for further research into the predictability of El Niño. Ironically, the forecasts never again matched that early success. When Shukla predicted a drought in India in 1997, confirmed by the models, the monsoon arrived as normal. The episode was a humbling reminder that even with powerful models and decades of expertise, the climate system still holds mysteries. In A Billion Butterflies, Shukla doesn’t shy away from these complexities. Instead, he reminds us that in science—as in life—just when we think we have the answers, the questions often change.

Shukla explains the immense complexity behind climate and weather modelling without losing the reader in technical jargon. He walks us through the evolution of models and how climate predictions are made using coupled models. With over 25 major modelling centres around the world, each using different resolutions and with different treatments of physical processes, it’s no surprise that their projections often diverge.

He notes that most current models focus solely on physical systems, but the frontier of climate science is rapidly expanding toward integrated Earth system models—ones that incorporate human activity. Shukla is candid about the challenge ahead, calling the development and validation of such models a ‘Herculean task’ for the global scientific community. Yet, his tone remains one of cautious optimism, encouraging continued collaboration and innovation in the face of complexity.

Building on the famous butterfly effect, Shukla didn’t just test how small atmospheric changes might influence weather outcomes—instead, he altered countless initial conditions at once, simulating the impact of billions of butterflies, which is where the book gets its title. His findings supported the idea that seasonal climate forecasting is possible and helped shift meteorology from deterministic short-term forecasting toward long-term climate prediction.

In the latter half of the book he shares how he founded his own research institution and helped set up a community college in the village where he grew up. He also writes about his experience as a lead author of the IPCC’s Fourth Assessment Report, which was recognised with the 2007 Nobel Peace Prize alongside Al Gore. Shukla gives an honest account of the difficulties scientists face—trying to communicate complex truths dealing with public doubt, political pushback, and attacks from corporate sectors.

Shukla ends A Billion Butterflies on a note of cautious optimism. He recalls the global response to the ozone crisis four decades ago, when 46 nations came together to phase out chlorofluorocarbons—an effort that eventually led to the only United Nations environmental agreement ratified by every country on Earth. Thanks to that action, ozone-depleting substances have been nearly eliminated, and the ozone layer is on track to recover by the 2060s.

It’s a powerful reminder that meaningful change is possible when nations—and individuals— take responsibility. As Shukla writes, it won’t be computer models that save us, but people: who take responsibility for future generations and choose to act. The book is a compelling read for anyone interested in climate science, development or how one life rooted in humility can influence the course of global change.

Book Name: A Billion Butterflies: A Life in Climate and Chaos Theory

Author: Jagadish Shukla

Publisher: Pan Macmillan

Pages: 324

Price: Rs 699