J.S. Sawyer was a British meteorologist who did a lot of groundbreaking work during his career. He was elected a Fellow of the Royal Society in 1962. He was a leader in meteorological research, including the characteristics of storm fronts and the cloud systems associated with fronts. His calculations of air flow over mountains are believed to be the first realistic computations of their kind. He was dedicated, brilliant, and prolific.
In September 1972 he published ‘Man-made Carbon Dioxide and the “Greenhouse” Effect’ in Nature.
“In spite of the enormous mass of the atmosphere and the very large energies involved in the weather systems which produce our climate, it is being realized that human activities are approaching a scale at which they cannot be completely ignored as possible contributors to climate and climatic change.”
”The increase of 25% CO2 expected by the end of the century therefore corresponds to an increase of 0.6°C in the world temperature – an amount somewhat greater than the climatic variation of recent centuries.”
And that’s what happened by 2000 – a 25 percent increase in atmospheric CO2, and a 0.6°C surface temperature rise.
Sawyer addressed the myth and misunderstanding that although CO2 is a trace gas in the atmosphere, meaning there’s not a lot of it compared to oxygen and nitrogen, these “minor constituents” have a “particularly significance” in determining the world’s climate. “Certain atmospheric gases, principally water vapor and carbon dioxide, absorb a significant part of the outgoing radiation and reradiate it both upwards and downwards”, thus magnifying its heating effects.
Compared to measurements of human carbon dioxide emissions from burning fossil fuels, Sawyer noted that only about half of those human emissions were remaining in the atmosphere. The other half, climate scientists had concluded, were being absorbed by the oceans and the biosphere. Sawyer wrote,
“Industrial development has recently been proceeding at an increasing rate so that the output of man-made carbon dioxide has been increasing more or less exponentially. So long as the carbon dioxide output continues to increase exponentially, it is reasonable to assume that about the same proportion as at present (about half) will remain in the atmosphere and about the same amount will go into the other reservoirs.”
I’ve heard people talk about these things over the years – of course, the rate of CO2 rise, the surface temperature increases, the oceanic CO2 absorption.
Until I read his paper, I didn’t realize that he was the one who spoke first. I listened to a 1985 interview where he described his paper as an “assessment”. An assessment that shows us the role and increasing effects of CO2 on the atmosphere were clearly understood in 1972.
Thank you, J.S. Sawyer.