Download Did scientists predict an impending ice age in the 1970s?

GLOBAL WARMING AND THE ARCHITECT – June ‘09
By Dean A. Biancavilla, AIA, LEED AP, Holmes King Kallquist & Associates,
Architects, Syracuse, NY [email protected]
THE NEXT ICE AGE ?? [DEFINITELY NOT ! ! ]
One of the things we have tried to do with this series is to cover some of the science which points to
the global climate change we are facing. Climate change ‘skeptics’ have used many false and
misleading arguments to downplay the science and contribute confusion, however there is one
argument which has often been used that is particularly misleading and false. You may have heard
this one already or read about it – it goes like this “…why should we believe these scientists about
global warming when back in the ‘70s they were predicting a new Ice Age?” You may have even
‘googled’ this ice age story and gotten hits for stories in Newsweek or other mass media
publications. But what is not stated is the misleading part of this story. It is that in peer-reviewed
scientific journals at the time this so-called ‘prediction’ was absent. In fact there was a majority of
scientific articles in those journals predicting global warming even though climatologists were
stating that more research had to be done so that the scientific community could better understand
the delicate nature and the complexities of the huge number of systems that were interrelated in the
global climate machine.
Check out this website : http://www.skepticalscience.com/ice-age-predictions-in-1970s.htm
If you go to this website, you will find the links [underlined text below] to all of the articles and
journals they refer to which we can’t duplicate here in this newsletter so I encourage you to go to the
website because the information is very detailed and illuminating. The following is from that
webpage :
“Did scientists predict an impending ice age in the 1970s?”
The skeptic argument...
“The first Earth Day was celebrated on April 22, 1970, amidst hysteria about the dangers of
a new ice age. The media had been spreading warnings of a cooling period since the
1950s, but those alarms grew louder in the 1970s... In 1975, cooling went from “one of the
most important problems” to a first-place tie for “death and misery.” The claims of global
catastrophe were remarkably similar to what the media deliver now about global warming
(source: Fire and Ice).”
What the science says...
“1970's ice age predictions were predominantly media based with the majority of scientific
papers predicting warming.”
“The notion that the 1970’s scientific consensus was for impending global cooling is
incorrect. In actuality, there were significantly more papers in the 1970’s predicting warming
than cooling.”
“Scientific studies in the 1970's re: global cooling”
“Most predictions of an impending ice age came from the popular press (eg - Newsweek,
NY Times, National Geographic, Time Magazine). As far as peer reviewed scientific papers
in the 1970s, very few papers (7 in total) predicted global cooling. Significantly more papers
(42 in total) predicted global warming due to CO2.”
Figure 1: Number of papers classified as predicting global cooling (blue) or warming (red).
In no year were there more cooling papers than warming papers (Peterson 2008).
Rasool and Schneider's ice age "projection"
“The main study cited by skeptics is Atmospheric Carbon Dioxide and Aerosols: Effects of
Large Increases on Global Climate (Rasool 1971). The paper doesn't actually predict an ice
age. Instead, it projects a possible scenario - if aerosol levels increased 6 to 8 times then
sustained those levels for several years, it may trigger an ice age. Historically, what
happened was aerosol levels fell. While it's unclear whether Rasool's calculations re
aerosol cooling were accurate, one inaccuracy was they underestimated climate's
sensitivity to CO2 by a factor of 3.”
“In the decades since their 1971 paper, many studies constraining climate sensitivity
calculate that if atmospheric CO2 was doubled, global temperatures would rise around 3°C.
These studies employ different methods (modelling, calculations from empirical
observations) looking at different time periods (the 20th century, the Holocene, past ice
ages), different aspects of climate (surface temperature, mid-tropospheric temperature,
ocean heat intake) and response to different forcings (volcanic, CO2, solar).”
“National Academy of Sciences - now and then”
“The most comprehensive study on the subject (and the closest thing to a scientific
consensus at the time) was the 1975 US National Academy of Sciences/National Research
Council Report. Their basic conclusion was "…we do not have a good quantitative
understanding of our climate machine and what determines its course. Without the
fundamental understanding, it does not seem possible to predict climate…"
“Contrast this with the US National Academy of Science's current position: "there is now
strong evidence that significant global warming is occurring... It is likely that most of the
warming in recent decades can be attributed to human activities... The scientific
understanding of climate change is now sufficiently clear to justify nations taking prompt
action." This is in a joint statement with the Academies of Science from Brazil, France,
Canada, China, Germany, India, Italy, Japan, Russia and the United Kingdom.”
“Other indications of current consensus”
“Other scientific bodies that have released statements endorsing anthropogenic global
warming include:
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National Oceanic and Atmospheric Administration
Environmental Protection Agency
NASA's Goddard Institute of Space Studies
American Geophysical Union
American Institute of Physics
National Center for Atmospheric Research
American Meteorological Society
The IPCC Fourth Assessment Report (AR4) draws upon the work of over 850 peer
reviewed studies
“None of these bodies (at least the ones that existed back then) endorsed ice age
predictions in the 70s.”
“So global cooling predictions in the 70s amounted to media and a handful of studies, even
then outweighed by global warming predictions. Today, an avalanche of studies and
overwhelming scientific consensus endorse anthropogenic global warming. To compare
cooling predictions in the 70s to the current situation is both inappropriate and misleading.”
“Further reading” [note the text highlighted in blue below are links in the original
webpage which will take you to the article quoted..]
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Was an imminent Ice Age predicted in the '70's? by William Connelly documents all
the scientific literature in the 70's on global cooling.
Past Cycles: Ice Age Speculations by Spencer Weart (part of the History of Global
Warming series) documents the development of ice age science.
Logical Science goes to the trouble of purchasing the 1975 National Academy of
Sciences report to see what the NAS had to say about global cooling in the 70's.
James Hansen responds to the claims that "Hansen predicted an ice age in the
70's", explaining the role of his computer program used in Rasool's paper.
Check out this New York Times article from 1956 that discusses a forecasted
increase in global temperatures as emissions from burning fossil fuels increase
atmospheric CO2. Thanks to George Morrison for the heads up.
Robert Brulle at the Wonk Room looks at a range of New York Times articles on
climate science in the late 60's and early 70's.
“Real Climate – Climate Science by Climate Scientists
Scientists”
sts”
One important group of climatologists and scientists who try to address the various arguments
which ‘skeptics’ come up with also maintain a website which gives full disclosure as to who
they are and their various backgrounds. http://www.realclimate.org
This site goes into the
various studies which are referenced by scientists around the globe that supports the
anthropogenic [that’s ‘man-made’ for you and me] causes of global climate change. I highly
recommend it the next time you want to check out the facts of a story you read about in the
mass media. The following is from their site which talks about who they are ….
“RealClimate is a commentary site on climate science by working climate scientists for the
interested public and journalists. We aim to provide a quick response to developing stories and
provide the context sometimes missing in mainstream commentary. The discussion here is
restricted to scientific topics and will not get involved in any political or economic implications of
the science. All posts are signed by the author(s), except 'group' posts which are collective efforts
from the whole team.”
See you next month.