The well-qualified amateur who threw the spotlight back on CO2

Guy Callendar in 1934, about the time he turned his attention to the CO2-climate question

Guy Callendar in 1934, about the time he turned his attention to the CO2-climate question

In April 1938, a brave outsider stood up and showed a room full of sceptical experts evidence that would drive a revolution in climate science. Guy Callendar had pulled together temperature data from many parts of the world that clearly revealed global warming for the first time. Though few in the audience believed that humans could influence a planet-spanning system like climate, that’s just what Guy told them we were doing, by producing CO2.

But when better-known audience members at the Royal Meteorological Society meeting in London challenged his results, Guy fought back with a lifetime of scientific experience. He had followed in the footsteps of his father, physicist Hugh Callendar, making science the ‘family business’. But in 1938 the major part of that business so far for Guy – fully exploring the properties of steam – was nearing an end. And though climate science remained largely a hobby for him, Guy’s contributions are fundamental to our understanding of the global warming that is still ongoing today.

Guy was born in Montreal, Canada, in 1898 when his father, a pioneer in X-ray and steam physics, was a professor at McGill University. Hugh, his wife, and their three children returned to their native UK before Guy was one, when Hugh took up a position at University College, London. He then moved on to Imperial College London, where he chaired the physics department from 1908-1929. Beyond X-rays and steam, Hugh invented equipment to accurately measure and record air temperatures, wind speeds, and the Sun’s radiation. Perhaps it was these tools that inspired Guy to collect weather data, which he called his ‘figs.’, through much of his life. He took measurements so accurate that at one point they were used to form the official temperature records for central England.

In 1905, Hugh’s professorial salary and inventions bought a four story, 22-room house in Ealing. Life wasn’t entirely idyllic however, as by then Guy had been accidentally blinded in one eye with a pin by his brother Leslie. Further danger followed partly from Hugh’s encouragement of his children’s interest in science. He converted a greenhouse in Ealing into a laboratory, only for Leslie to destroy it while trying to make TNT. With his partial blindness preventing him from fighting in the First World War, Guy left school in 1915 to join his father’s laboratory. He performed X-ray tests, such as looking for cracks and other faults in aircraft engines, introducing him to the science of energy carried in waves. Read the rest of this entry »