Years ago, the idea that human activity can influence our climate was considered a bad joke. People who in those times made an effort to understand and communicate the scientific evidence deserve our profound thanks. One of these pioneering souls is Murray Yaxley, now retired from an outstanding science teaching career. [27 October 2009 | Peter Boyer]
About three years ago I embarked on a little personal project, studying the history of the science that underpins our knowledge of climate change today. For me, a life-long student of history, it’s been a real voyage of discovery.
I’ve been guided in this journey by a splendidly informative, well-told account by physicist and historian Spencer J. Weart. Along the way I’ve had lots of small surprises, discovering in old scientific publications little insights that threw light on this or that aspect of greenhouse warming.
A month ago I got a big surprise. Nel Smit, a member of the Tasmanian Climate Action Council, gave me a photocopy of a battered newspaper cutting, more than half a century old. It came from, of all publications, Hobart’s Mercury newspaper, dated Tuesday, August 25, 1959.
“Ice Caps Could Melt And Drown Cities” was the shocking heading on an article by The Mercury’s school science writer, “Rhombus”. What followed was no brief, sensationalist piece, but a detailed account of a discovery first described in a scientific paper only two years earlier.
In 1957, oceanographer Roger Revelle and physicist Hans Suess, of the Scripps Institute of Oceanography in California, published a paper in the Swedish geophysics journal, Tellus, called “Carbon dioxide exchange between atmosphere and ocean and the question of an increase of atmospheric CO2 during the past decades.”
Revelle had been working for some years on what he saw as a worrying upward trend in the amount of carbon dioxide in the air, and Suess had found a way of identifying carbon dioxide molecules that had come from fossil fuel burning.
The result was a warning by Revelle and Suess that the oceans were unlikely to be able to absorb excess carbon dioxide quickly enough to prevent warming of the atmosphere, possibly as soon as the turn of the century.
The Mercury account looked at the science behind Revelle’s thesis, explaining that carbon dioxide, while making up only about 0.03 per cent of the atmosphere, was a potent greenhouse gas, and describing how it traps infrared rays — solar radiation reflected from Earth’s surface.
“In the past 100 years, furnaces and the exhausts of cars, aeroplanes, and other internal combustion engines have belched out about 360,000 million tons of carbon dioxide,” the article said.
“We know that the rate of production of carbon dioxide from burning coal and oil products is increasing.
“Due to the glasshouse effect, this extra carbon dioxide could bring about a rise of one to two degrees centigrade in air temperature. If this happened the desert regions of the earth would be extended, the seas would get warmer, and release even more carbon dioxide from solution.
“This would increase the ‘glasshouse’ effect still more. Sooner or later, the Arctic and Antarctic ice caps would melt, adding enough water to the oceans to drown nearly all of the earth’s great cities.”
Far-sighted “Rhombus” seemed like someone I should get acquainted with. Next to the article was a story about observing the sun. There was a photograph of a few students with Murray Yaxley, senior science master at Hobart High School, who I remembered from my own time as a student at the school in the early 1960s.
Mr Yaxley, still living in Hobart, was in a group I spoke to about climate change earlier this year. On a hunch I found his telephone number and called him.
And I discovered that right now, in this 21st century, Rhombus was alive, well, and none other than Mr Yaxley himself. In an enjoyable discussion at his home ranging across climate, science and life, I found him to be as lucid and thoughtful as he was then, all those years ago.
Good teachers are the greatest gift any community can bestow on itself. Mr Yaxley was one of the best. I am delighted to have re-discovered him much later in his life, both in person and through his remarkably prescient writing.
• You can find out more — much more — about the history of climate science in Spencer Weart’s history section of the American Institute of Physics website.
Here is the full text of the article on global warming, written for school students, published by The Mercury in August 1959. Apart from the implication that cities could be under water by 2000 (though this is not explicitly stated), Murray Yaxley’s detailed explanation of greenhouse (“glasshouse”) warming stands up well today.
The Mercury, Tuesday, 25/8/1959
Ice Caps Could Melt And Drown Cities
[Science By Rhombus]
THE increasing amount of carbon dioxide in the air could increase the temperature so much in the next 40 years that the ice caps could melt, causing the oceans to drown nearly all the great cities.
We are well aware that energy from the sun reaches us through millions of miles of empty space.
Sir Humphrey Davy showed that heat passes through a vacuum by electrically heating a wire inside the best vacuum he could produce, and detecting the heat radiated outside by a sensitive thermometer covered with lamp black, since it had been found that a black surface was more sensitive to small quantities of heat. This form of heat transfer is called radiation.
People are often unaware that all bodies continuously give out radiation. Of course as the temperature is increased, the rate of emission of heat also increases.
Under steady temperature conditions the rate of absorption of radiant heat from its surroundings is equal to the rate of emission of heat by a body.
An interesting example of radiation and absorption is that of the hothouse. Solar radiations can be shown to travel in waves that vary systematically from long radio waves through heat, and infra red waves to light. These are part of what we call the electromagnetic spectrum.
Now, glass is found to transmit only short-wave radiations, such as those that are visible, and the shorter of the heat radiations. These therefore pass through glass roofs, and are absorbed by the plants, earth, and other contents of the hothouse.
But when the energy is re-radiated by these plants, and the soil, it is as long heat waves. Only very hot bodies give off short heat waves. The long heat waves cannot pass through the glass. The hothouse or glasshouse becomes warmed and does not quickly lose its heat.
This so-called “greenhouse” or “glasshouse” effect applies to the whole of the earth on a grand scale.
The temperature of the earth’s surface depends to a considerable extent on the atmosphere’s small content of carbon dioxide — about 0.03 p.c.
This gas permits the entry of short-wave sunlight and infra-red rays from the very hot sun, but blocks the escape of longer heat waves radiated towards space by the colder earth.
In the past 100 years, furnaces and the exhausts of cars, aeroplanes, and other internal combustion engines have belched out about 360,000 million tons of carbon dioxide.
We know that the rate of production of carbon dioxide from burning coal and oil products is increasing.
In fact, by the year 2000 we may have added 1,700,000 million tons. This is 70 p.c. of what is now present in the atmosphere.
We expect, and hope, that the oceans will absorb most of this extra carbon dioxide, but in any event the amount of this gas in the atmosphere is likely to increase by 20 per cent.
Due to the glasshouse effect, this extra carbon dioxide could bring about a rise of one to two degrees centigrade in air temperature.
If this happened the desert regions of the earth would be extended, the seas would get warmer, and release even more carbon dioxide from solution.
This would increase the “glasshouse” effect still more. Sooner or later, the Arctic and Antarctic ice caps would melt, adding enough water to the oceans to drown nearly all of the earth’s great cities.
This is largely speculation, but it is worth very serious attention. It has been put forward by Dr Roger Revelle, who is director of the Scripps Institution of Oceanography in California.
If you are an optimist about the earth’s future, you will examine these arguments carefully, and perhaps you will be able to suggest a way out of the predicament.
After all, it concerns you — you will still be on earth in the year 2000.