The history of today's climate change debate may have begun on Feb 7, 1861. That day, an Irish physicist named John Tyndall, a professor of natural philosophy, delivered the annual Bakerian Lecture to the Royal Society in London. Dark-eyed and quick-witted, Tyndall was a dazzling figure who drew huge audiences to his public lectures on lively new subjects like glaciation, radiation and sound.

"I never saw so large an attendance in the rooms of the society," he wrote in his journal that night. Even Alfred Tennyson, the poet laureate, sat amid the "many remarkable men present".

Tyndall had news. He revealed that for two years he had been studying the heat-absorbing properties of gases. He realised that for the earth's atmosphere to maintain its steady temperature, certain gases must be capable of trapping radiant heat. This inquiry, he said, was "perfectly unbroken ground". His experiments had shown that gases like oxygen, hydrogen and nitrogen retained very little heat. But others, particularly carbon dioxide, absorbed surprising amounts of radiation - "nearly 100 times as much as oxygen", he said.

Today's climate change debate has evolved much like the forecasting controversy of the 1860s. Similar questions arise: How can we trust scientists to warn of coming danger? What are the economic costs? Meteorology is one of the few applied sciences that demand prediction. PHOTO: EUROPEAN PRESSPHOTO AGENCY

For the sharp minds in the hall, the implication of Tyndall's discovery was clear. The higher the concentrations of absorptive gases in the atmosphere, the higher atmospheric temperatures would be. Thus was laid the theoretical foundation for climate science - though few could have envisioned that, more than 150 years later, Tyndall's discovery would be one of the great political debates of the day.

Tyndall's was not the only contribution that year to our understanding of earth's climate and its threats. That bleak winter week in 1861 was a stormy one. As Tyndall spoke, Atlantic gales were tearing across England, from the Irish coast to the North Sea. A 10-minute walk from where Tyndall was giving his lecture in London, a veteran of the Royal Navy, Robert FitzRoy, was embarking on an audacious meteorological experiment.

Tyndall knew FitzRoy. They mixed in London's intellectual circles and had served on the same British Association committee. For the previous seven years, too, FitzRoy had been making a name for himself, as head of the British government's new Meteorological Department.

The initial aim of this department was to collate wind data from ships' logs and plot the findings on nautical maps. Mimicking a similar initiative in the United States, the government hoped that British captains could plan more intelligent routes, making merchant shipping more efficient. But then FitzRoy changed tack.

He was an energetic, independent-minded man, who three decades earlier had captained the Beagle during its celebrated circumnavigation with the young Charles Darwin aboard. Around Cape Horn and the bleak coastline of Tierra del Fuego, FitzRoy had studied weather patterns, learning to predict sudden atmospheric changes.

Meteorological theory had progressed during his career, but to little practical effect. The sky was considered by many a divine realm, not a place for science. So storms continued to blow over Britain without warning, sinking ships and boats as they passed. In the 1850s, more than 1,000 sailors drowned off the British coast each year.

For the admiral, this was an outrage. By February 1861, he had the authority to act. At his office in Whitehall, he studied weather reports from the coast. If he detected a storm, he would relay a telegram to the relevant port, where a warning signal could be hoisted in the harbour. His first storm warning was sent within hours of Tyndall's lecture. Even with the new communications technology, it was, he wrote, a race "to warn our outpost before the gale reaches them".

It was an exhausting undertaking. All the telegraphed slips were read, collated and analysed. Everything was time-sensitive.

Often, the warnings turned out to be right, saving lives. FitzRoy became a national celebrity, called the "Clerk of the Weather" in the newspapers. Within six months, his storm-warning project had evolved into full-blown weather predictions issued under a new term of his own: forecasts.

Despite huge popular appeal, they remained highly controversial. Religious men doubted whether anyone could pretend to know the mind of God, while scientists attacked the admiral's lack of theory and penny-pinching MPs complained about the cost of telegraphy. He struggled with the diplomatic challenge of securing data from rival powers like France, and with the inevitable, sometimes-costly failures of his weather forecasting.

The burden became too much. Depressed and ailing, on April 30, 1865, he locked himself in his dressing room and cut his throat with a razor.

Today's climate change debate has evolved much like the forecasting controversy of the 1860s. Similar questions arise: How can we trust scientists to warn of coming danger? What economic costs should we expect?

These climate disputes continue to resonate in part because meteorology is among the most difficult of sciences. It is one of the few fields of applied science that demand prediction. As any prediction involves uncertainty and uncertainty is anathema to scientists, meteorology seems condemned to exist in a fraught intellectual space.

Despite FitzRoy's tragic end, history has judged him favourably. The science of forecasting that he pioneered has become an ingrained part of modern life, right down to the weather app on our phones.

The British Met Office has its headquarters in FitzRoy Road, and in 2002, one of the zones in the BBC shipping forecast was renamed FitzRoy in his honour. More than a century and a half after Tyndall's greenhouse-gas lecture and FitzRoy's first storm warning, we again find ourselves in a time when meteorological work is often criticised as costly and inaccurate.

Yet today's climate scientists can take heart from FitzRoy's story. His work is viewed as a triumph of practical science against fierce opposition, and a celebration of that rare sort of human will we need to make change possible.

NEW YORK TIMES