40 Years On: 'It's Time We Start Listening' to Global Warming Prediction
Paper written four decades ago warned of global warming, accurately predicted temperature rise
Citing a peer reviewed scientific paper written over 40 years ago that clearly demonstrated the dangers of human-made carbon pollution and accurately predicted it would create a future of global warming, Dana Nuccitelli at the Guardian points out Thursday that "perhaps it's about time that we start listening" to climate scientists.
The paper, written by renowned British meteorologist John Stanley Sawyer and published in the journal Nature (pdf) in 1972, estimated that carbon dioxide levels would increase 25 percent by 2000 from 1850 levels and that global average surface temperatures would rise by 0.6°C.
Sawyer's numbers were just about dead on, Nuccitelli reports.
The rise in human-made carbon pollution and increase in temperature were undeniably related, Sawyer warned, and would cause changes in weather and wind patterns around the world.
A recent reading from the he carbon dioxide monitoring program at the Scripps Institute of Oceanography showed atmospheric concentration of carbon dioxide temporarily surpassed 400 parts per million two months earlier than last year. Ralph Keeling at the institute warned it is only a matter of time before the atmosphere permanently maintains those levels, which climate scientists have long said the earth cannot withstand without tipping the scales against human life once and for all.
Sawyer and his colleagues saw this coming four decades ago.
"Bolin has estimated that the concentration of carbon dioxide will be about 400 ppm by the year 2000," wrote Sawyer. "A recent conference put the figure somewhat lower (375 ppm)."
The year 2000 saw carbon around 370 ppm, which has gone up since, and, as Keeling warns, may soon permanently surpass the tipping point.
"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," wrote Sawyer. "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."
While half of the carbon adds to the greenhouse effect in the atmosphere, the rest is absorbed in the ocean and biosphere, Sawyer accurately noted. Hence, this relentless excess of carbon has also led to what scientists are now calling global warming's "evil twin"—the acidification of the world's oceans.
"All in all, Sawyer's 1972 paper demonstrated a solid understanding of the fundamental workings of the global climate, and included a remarkably accurate prediction of global warming over the next 30 years," writes Nuccitelli. "Sawyer's paper was followed by similarly accurate global warming predictions by Wallace Broecker in 1975 and James Hansen in 1981."