Climate Science Glossary

Term Lookup

Enter a term in the search box to find its definition.


Use the controls in the far right panel to increase or decrease the number of terms automatically displayed (or to completely turn that feature off).

Term Lookup


All IPCC definitions taken from Climate Change 2007: The Physical Science Basis. Working Group I Contribution to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change, Annex I, Glossary, pp. 941-954. Cambridge University Press.

Home Arguments Software Resources Comments The Consensus Project Translations About Support

Bluesky Facebook LinkedIn Mastodon MeWe

Twitter YouTube RSS Posts RSS Comments Email Subscribe

Climate's changed before
It's the sun
It's not bad
There is no consensus
It's cooling
Models are unreliable
Temp record is unreliable
Animals and plants can adapt
It hasn't warmed since 1998
Antarctica is gaining ice
View All Arguments...

New? Register here
Forgot your password?

Latest Posts


LBJ's climate warning 50 years ago - do we have your attention yet?

Posted on 18 February 2015 by Glenn Tamblyn

An old saying in marketing and communications says: ‘Repeat it, and repeat it, and repeat it again. When you are tired of repeating it, people might just start to take notice’. Sometimes this can seem oh too true. Particularly where warnings about unexpected dangers are concerned.

In 1951 U.S. President Harry Truman established the Science Advisory Committee as part of the U.S. Office of Defense Mobilization. After the launch of Sputnik in 1957 President Eisenhower renamed it the President’s Science Advisory Committee and moved it into the White House.

The committee wrote many reports for U.S. presidents, often on defense issues. But they also produced a large report – ‘Restoring The Quality of Our Environment’ – tackling a wide range of environmental and pollution problems of the time.


Included within this report was a 23 page appendix, ‘Appendix Y4 – Atmospheric Carbon Dioxide.

This was the first official report to any government anywhere in the world on the possible challenge rising Carbon Dioxide (CO2) levels in the atmosphere might pose. The report was presented to President Lyndon Johnson in 1965;

Half a century ago!

President Johnson made a speech to Congress about the report, including a reference to rising CO2 levels.

                                Lyndon Baines Johnson, 36th President of the United States

Some of the insights in the report are resonant today

Within a few short centuries, we are returning to the air a significant part of the carbon that was extracted by plants and buried in the sediments during half a billion years

Through his worldwide industrial civilization, Man is unwittingly conducting a vast geophysical experiment. Within a few generations he is burning the fossil fuels that slowly accumulated in the earth over the past 500 million years

By the year 2000 the increase in CO2 will be close to 25%. This may be sufficient to produce measurable and perhaps marked changes in climate.

The climate changes that may be produced by the increased CO2 content could be deleterious from the point of view of human beings.

The report was far more circumspect than reports we would read today but still covered many familiar subjects. In addition to the possibility of warming air temperatures the report discussed issues such as the melting of the Antarctic ice cap, rising sea levels, less carbon in the soil, warming of the oceans and resultant carbon dioxide ‘outgassing’.

It even covered a what-if scenario; what if we need to find a way to cool the earth?

The possibilities of deliberately bringing about countervailing climatic changes therefore need to be thoroughly explored…for example by spreading very small reflecting particles over large oceanic areas

They foresaw, half a century ago, the need for research that is currently being undertaken into ‘geoengineering’ to look for ways to artificially cool the earth if we don’t control our CO2 emissions.

One quote from the report is significant, referring to modelling of the climate:

‘A more comprehensive model is being developed by the U.S. Weather Bureau. This includes processes of convection and of latent heat transfer through the evaporation and condensation of water vapor’

Two years later, Syukuro Manabe and Richard Wetherald published a scientific paper – ‘Thermal equilibrium of the atmosphere with a given distribution of relative humidity’ – that built on previous work by them and others through the late 50’s and early 60’s. It is still regarded as the essentially correct description of the workings of the ‘greenhouse effect’ that warms the earth; it was their work the report was referring to.

Old science is Good Science

Listed in the references for the appendix are around three dozen scientific papers from the 50’s and early 60’s and even earlier, back to the 19th century. They cover the earliest research developing our understanding of how CO2 influences climate.

Many of the names may be familiar to aficionados of climate science history, but they are hardly household names: Manabe, Wetherald, Moller, Bolin, Lamb, Erickson, Broecker, Plass, Kaplan, Callender, Arrhenius, Chamberlain, Revelle, Suess, and Keeling.

These were some of the fathers of our modern understanding of climate and the role of CO2. Many of these early researchers are no longer here – Gilbert Plass died in 2004 and Richard Wetherald in 2011 – although Syukuro (‘Suki’) Manabe, now one of the Grand Old Men of Science, is still with us.


                                                            'Suki' Manabe today

One researcher needs special mention, simply because his words were so prescient. Professor Gilbert Plass was a physicist during the Cold War often working, as many others did, with military funding.

                                                  Gilbert Plass during the 50's

In the mid-50’s he was about the first person to use the newly emerging power of computers to do the detailed calculations needed to analyze how infra-red (heat) radiation moves through the atmosphere. He didn’t get everything right, in fact two of his errors essentially cancelled each other out. But he pioneered some of the basic research that led to Manabe and Wetherald’s results a decade later.

Plass predicted that a doubling of CO2 might cause warming of 3.6°C; that CO2 concentrations would be 30% higher in 2000 than in 1900; and that the earth would be about 1°C warmer in 2000 than in 1900.

His research culminated in the publication of his paper - ‘The Carbon Dioxide Theory of Climate Change’ - in the journal Tellus in 1956.

A rather evocative name!

That same year (1956) Gilbert Plass said:

If at the end of this century the average temperature has continued to rise and in addition measurement also shows that the atmospheric carbon dioxide amount has also increased, then it will be firmly established that carbon dioxide is a determining factor in causing climatic change.

Since then measurements have shown that CO2 amounts have risen. And temperatures have risen. Roughly by the amounts Plass projected.

There ain't no hoax like an old hoax

Gilbert Plass’s paper contains an interesting credit: ‘This work was sponsored by the U.S. Office of Naval Research’.

The Office of Naval Research was one of the major funding agencies for US military research during the Cold War.

It is interesting to reflect. Two of the people most often vilified by so-called climate change skeptics are Al Gore, and James Hansen previously from NASA. In 1956, when Gilbert Plass wrote those words, Al Gore was 8 years old and James Hansen was 15 – still in high school.

For all those climate change ‘skeptics’ with conspiracy theories about climate change - that it is all some sort of recent, giant hoax – perhaps they might want to ask themselves some simple questions:

  • Why did presidents Truman and Eisenhower start this hoax at the height of the Cold War?
  • Why was the Office of Naval Research funding frauds like this?
  • Why start a hoax that takes half a century or more to play out and only reaches fruition after you are dead?

More seriously, how can half a century have passed since this first tentative warning; half a century of expanding science; far more certainty; more data; many, many, more people thinking about the problem and better warnings.

And yet we are still just tentatively thinking about maybe, perhaps, when we can get around to it, doing something about it? If we can fit it in to our busy schedule of economics, and business, and daily life and, you know, stuff?

What is it with us? If Gilbert Plass or ‘Suki’ Manabe could see the possibility of this half a century ago, why can’t we see it today?

Well what have we learnt in that half century?

Measurements from satellites have confirmed the understanding in Manabe & Wetherald’s paper. Since 1969 - the year Neil & Buzz landed on the moon - we have been observing the greenhouse effect from space and how it is changing.

Geologists and paleo-climatologists have examined the geological record of the last 500 million years; it shows that major climate changes, mass extinctions including the biggest extinctions ever recorded, and frightening disruptions to the chemistry of the oceans have occurred repeatedly. And CO2 played a major part in much of this. When CO2 levels change, climate changes, sometimes very, very, seriously. During the biggest mass extinction event ever, 252 million years ago, over 90% of species went extinct, as CO2 levels climbed hugely and temperatures rose; the tropical regions may well have been uninhabitable for  most complex life. 

And the rate of change of CO2 concentrations today is 10 to a 100 times faster than at any time in the last 500 million years. Humanity with our wondrous harnessing of technology are changing the world faster than just about any time in the past.

If we look back over the cycle of ice ages over the last 800,000 years for example we see CO2 concentrations in the air changing as the earth cools and warms, driven initially by changes in the Earth's orbital parameters. Typically CO2 concentrations changed by ½ to 1 part per million (ppm) every century as the world slowly swung in and out of ice ages, contributing to the swings.

Today average CO2 levels change by 1 ppm every 20 weeks!

It’s no wonder that the International Commission on Stratigraphy, the peak geological body that sets the definitions for the boundaries between geological periods, is discussing the formalization of the next geological period. The ‘Anthropocene’ – the geological age of Man. When we truly leave our mark in the rocks for all of time!

The world is warming. Sea level is rising and the oceans are like the earth’s thermometer; just as a liquid expands and rises up a thermometer tube, so warming oceans expand and rise. And as well, all over the world, ice is melting.

Life on earth is responding. All over the world species are moving - Bluefin tuna are appearing in the Arctic for example. Seasons are shifting, flowering times are changing, pests are spreading like the Pine Bark Beetle in North America devastating pine forests; and agriculture is dealing with moving challenges.

And the scientists now understand the ‘carbon cycle’ in much more detail. If we release too much CO2 into the atmosphere, part of it will be removed naturally within a few decades. But, depending how much we release, it will take centuries, maybe 1000’s of years before atmospheric CO2 levels fully return to ‘normal’. And temperatures return to ‘normal’.

Everything we have learnt says this is real, serious and urgent. Go look in the rocks, they tell the story of what can happen when climate runs amok.

A new theme?

Historians often analyze history in terms of ‘themes’ – connecting narratives that let us make sense of things. Empire, Land, Religion, Technology, Culture, these are some of the themes.

Think back to the time of Christ, Julius Caesar, King Tutankhamen. Now imagine that all of history since then had been dominated by one theme, one topic. Climate. We are adding a new theme that may be the biggest narrative in history for thousands of years to come. Our descendants will most definitely remember us!

Don’t believe it? Go talk to the chemists studying the ‘carbon cycle’, or the changes in ‘carbonate saturation’ in the ocean. Or go talk to the geologists studying past climates. When the biggest mass extinction event occurred 252 million years ago, at the end of the Permian period, it left another mark. The Coal Gap. For 10 million years after the event, essentially no new coal was created. Because the forests that coal is formed from had been so devastated that it took them 10 million years to recover.

Go talk to the scientists! The inheritors of the mantle from Suki and Gilbert, Roger and Hans, Svante and Guy. Go talk to them. Because they are scared! They have been warning us for 2-3 generations. Warning us that we have a Very Big Problem and we need to do something about it.

We can solve it. There are 7 billion of us on this earth, 7 billion brains we can throw at solving anything. But the first step is to choose to do so. Until we really choose to act, really choose, we can’t solve anything.

So just how long does it take before we wake up? REALLY WAKE UP!

Has this been repeated often enough yet?

0 0

Printable Version  |  Link to this page


Comments 1 to 2:

  1. Thanks for this. Great points to counter the misimpression of many contrarians that concerns over global warming are primarily based on an Inconvenient Truth, or began with the formation IPCC, ideas that the conspiracy minded really want to hold on to. That the reality of today syncs very well with the scientific understanding of half a century ago, forming a foundation for continued understanding is a powerful argument for climate science.

    0 0
  2. Speaking of presidents and climate, CC has a nice interactive chart on that theme here.

    0 0

You need to be logged in to post a comment. Login via the left margin or if you're new, register here.

The Consensus Project Website


(free to republish)

© Copyright 2024 John Cook
Home | Translations | About Us | Privacy | Contact Us