The Irishman behind the science of climate change

Thu, Sep 22, 2011, 01:00

John Tyndall, born in Co Carlow in 1820, became one of the great scientists of Victorian England, and his work still underpins some of the most important science happening in the world today, writes MARY MULVIHILL

IN 1861, after two year’s of painstaking experiments, John Tyndall published a lengthy paper packed with results. Among the findings, he reported that moist air absorbs 13 times more heat than dry, purified air.

That might not seem Earth-shattering, yet scientists now agree that this marks the start of our understanding of the “greenhouse effect”. It explains how our atmosphere, with its clouds, water vapour and ozone, can absorb heat from the Sun and warm the planet enough to sustain life. It also tells how changing the mix of gases in the atmosphere will directly affect the planet’s temperature.

Previously, people believed that different climates were due to differences in the amount of atmosphere present: that colder places had a thinner atmosphere, for instance, than places with a warm climate. John Tyndall discovered that it was the composition of the atmosphere that was most important, and not the amount.

In 1861, he devoted one page of his long paper to discussing this result, yet he clearly appreciated its significance: “Now if, as the above experiments indicate, the chief influence be exercised by the aqueous vapour, every variation of this constituent must produce a change of climate.”

For this, he is the acknowledged founder of the science of climate change. Today, the Tyndall Institute for Climate Change Research in England is named after him, and a sister institute in Shanghai, the Tyndall Fudan Centre, opened earlier this year. Not bad for a man who came from modest beginnings in a Co Carlow village.

Next week, to mark the 150th anniversary of his landmark publication, scientists from around the world will gather in Dublin for a conference on climate change. The meeting, organised by the Environmental Protection Agency and the Royal Irish Academy, includes a public lecture on Tyndall’s legacy.

The conference organisers have put the 1861 paper online, and it is worth reading, not least because it shows how skilled an investigator Tyndall was. The experiment was designed to measure how much heat various gases absorb. An accompanying diagram reveals a complicated set-up.

Initially, trying to calibrate the instruments, Tyndall realises there must be some interference from something. He eventually tracks it to the green silk that was used to wrap some wiring. The green dye, he concluded, must contain some magnetic compound, so he replaced it with white fabric, and the experiment proceeded.

It was this attention to detail that made Tyndall’s experiment more successful than previous attempts by other scientists. This plus a dogged determination: Tyndall ran this experiment on and off for nearly two years. And it was this determination that also brought Tyndall to be one of the great scientists of Victorian England.

As well as being an important experimentalist, he was a gifted teacher, an ardent – some would say even pugnacious – champion of science, and a great populariser who was famous for his public lectures.

His talks at the Royal Institution in London were often theatrical and attracted huge crowds. And on a US lecture tour in the 1870s, the transcript of his lectures sold over 200,000 copies.

It wasn’t all science either – Tyndall was also a keen mountaineer, in the first party to climb the Weisshorn, and among the first to ascend the Matterhorn.

So who was John Tyndall?

He was born in 1820 in Leighlinbridge, where his father was a shoemaker and, later, a constable. He received a good education from a local schoolmaster, John Conwill, that included mathematics and surveying techniques.

This was perfect for entry to the Ordnance Survey of Ireland – then the country’s biggest employer of technical people as it mapped every inch of the island. Tyndall joined the OSI in 1839, aged 19, and after two years in Ireland, moved to surveying in England.

His next job, as a mathematics teacher, changed his life. Another teacher there was Edward Frankland, later one of the great chemists of his day and a lifelong friend.

The two young men would wake early and study together, Frankland teaching Tyndall chemistry, Tyndall teaching Frankland mathematics. After a year, Frankland left for Germany, where he had previously studied. Tyndall gave up his job and followed, believing that science education in Germany was better than in England, where the emphasis was still on the Classics.

In 1851, back in England with a PhD from Marburg, Tyndall gave a talk at the British Associations summer festival of science – the same science festival that took place in Bradford last week. That brought an invitation to talk at the prestigious Royal Institution in London, and by 1853 Tyndall was a professor there. He spent the next 34 years at the RI, succeeding Michael Faraday as director when Faraday died in 1867.

Tyndall’s scientific interests ranged from magnetism to heat and light, and especially the composition of air (see panel). He was interested in how glaciers move, having discovered a love of Alpine mountaineering while studying in Germany.

He was also a vocal champion of science, campaigning for a higher profile for science in politics, public life and education, and arguing that research should be driven by curiosity alone, and not for profit – though profits could follow. He helped to found the prestigious journal, Nature, which still publishes the latest scientific research every Thursday from London.

Pugnacious by nature, Tyndall provided an infamous flash point in the science versus religion debate that followed publication of Darwins book, On the Origin of Species. Speaking at the British Association’s summer festival in Belfast in 1874, Tyndall, by now president of the association, urged that religion and the churches should stay away from matters that were more appropriate to science. His incendiary speech lit a fuse that would burn for years.

Sadly, his later years were plagued by ill health and insomnia, until one day his wife, mixing up his medicines, gave him the wrong dose of sleeping draught. Despite emetics and stomach pumps, the great Irish-born scientist died that evening.

Mary Mulvihill is a science writer and broadcaster. For more about her talks and tours on Ireland’s scientific heritage see ingeniousireland.ie

For details of the EPA-RIA conference, public talk and Tyndall’s 1861 paper see tyndallconference2011.org

Tyndall’s obsession with dust

Some people are obsessed with cleanliness, but John Tyndall (left and right) was fascinated by dust, or what he called the “floating matter of the air”.

It is there today. We all see it when sunshine slants through the window but how many of us would have bothered to find out about that floating matter?

That fascination stayed with Tyndall and ultimately led him to being the first to explain why the sky is blue.

It also helped him to provide the definitive proof of Pasteur’s germ theory of disease, inventing a better respirator for fire-fighters, and devising a sterilising technique that kills bacterial spores more effectively than pasteurisation.

All of these stemmed from realising that there are minute particles of matter in the air, and that these can scatter light (hence making the sky seem blue), or can be harmful bacteria and spores that carry disease and infection.

It is a tribute to the man from Leighlinbridge that so much is named after him: the Tyndall effect, Tyndall scattering and Tyndallisation to name a few.

Also the Tyndall National Insitute at UCC, which today continues research into many of John Tyndall’s scientific interests, including light, electronics, and nanotechnologies – those tiny particles that some might call dust.

– Mary Mulvihill