RETHINKING THE

GREENHOUSE EFFECT
William Kininmonth

The Global Warming Policy Foundation
Note 34

Rethinking the Greenhouse EffectWilliam Kininmonth
Note 34, The Global Warming Policy Foundation© Copyright 2022, The Global Warming Policy Foundation

Contents
About the author	iiiIntroduction	

1

The greenhouse effect	2Equatorial ocean and lower atmosphere temperature	4

Summary	

7

Notes	9

About the Global Warming Policy Foundation	

11‘The pattern of recent global warming
underscores the validity of what
meteorologists widely recognise: the oceans
are the vital inertial and thermal flywheelsof the climate sys­tem. The corollary is, if one
wants to control climate, it will be necessary
to control the oceans. Efforts to decarbonisein the hope of affecting global temperatures
will be in vain.’

About the author
William Kininmonth joined the Australian Bureau of Meteorology in 1960, and retired in 1998 ashead of the National Climate Centre. He was a consultant to the World Meteorological Organization’s Commission for Climatology and participated in regional coordination and training programs. William Kininmonth is author of Climate Change: A Natural Hazard (2004, Multi-Science Publishing).
iii

Introduction
The widely held belief that humans are causing a climate emergency has its origins in the claim that greenhouse gases keep
the planet warm by absorbing Earth’s radiation,1 preventing it
escaping to space. From this understanding, it would naturally
follow that releasing more greenhouse gases, specifically carbon
dioxide from industrial emissions, will lead to more warming. The
claim is an extension of a theory proposed in the 1820s by Frenchmathematician Joseph Fourier, which was later used by Swedish
chemist Svante Arrhenius in his 1896 hypothesis for the cause of
ice ages.
The Intergovernmental Panel on Climate Change (IPCC) isthe body created by the United Nations to advise governmentson the potential impacts of carbon dioxide on future climate. Its
explanation for anthropogenic global warming assumes that
Earth was in radiation balance prior to industrialisation; that is,
the planet’s temperature was stable because, at the top of the atmosphere, incoming solar radiation2 was offset by an equal magnitude of longwave radiation emission to space.
Burning of fossil fuels has undoubtedly increased the carbon
dioxide concentration of the atmosphere. In the IPCC’s explanation, as the concentration has increased, there has been a reduction in the intensity of radiation emitted to space. This so-called‘radiation forcing’ heats the atmosphere.
The reality of the greenhouse effect is, however, much more
complex than just the absorption of Earth’s radiation by greenhouse gases3 and the balance of radiation at the top of the atmosphere. It has been understood for more than 60 years thatgreenhouse gases emit more radiation – to space and back to
Earth – than they absorb. The atmosphere is only prevented fromcooling by a constant flow of heat and latent energy (the evaporation of water vapour) from the Earth’s surface. It is impossible
to properly understand what is going on without considering
these enormous flows of energy.
The IPCC’s construct also overlooks the fact that Earth is asphere, and what happens at different latitudes is very different:
most absorption of solar radiation takes place over the tropics,
while there is excess emission of longwave radiation to spaceover higher latitudes.4 Nowhere is there local radiation balance.
The ocean currents and winds of the atmosphere are constantly
transporting excess heat from the tropics to higher latitudes as
the dynamics of the climate system strive to achieve global radiation balance. However, any balance is only transitory becauseof the different rates of transport by the oceans and atmosphereand the seasonally changing pattern of solar heating.
The absence of global radiation balance is exemplified by
the fact that Earth’s average surface temperature is not constant;it has an annual range exceeding 2.5°C. This shows that the global emission of longwave radiation to space must vary throughthe year. This can only mean that the amount of heat radiated1to space is a function of Earth’s changing temperature, which
in turn means radiation to space cannot in any way be defining
Earth’s temperature, either locally or globally.
An alternative approach to explaining why Earth’s temperature is changing is to follow the course of energy as it traverses
the climate system, from absorption over the tropics, transport
poleward by the atmospheric and oceanic currents, to emission
to space over higher latitudes. In this way, it is possible to see:•

how the surface energy budget defines Earth’s greenhouseeffect;•that solar radiation absorbed over the tropical oceans forms
a surface layer heat reservoir, which in turn regulates heatexchange to the atmosphere;•

how temperatures over high northern latitudes respond as
the winds transport heat from the tropics.

The conclusion to be drawn is that changing atmospheric carbon
dioxide has minimal impact on Earth’s temperature and climate.
In fact, the temperature changes observed over the recent four
decades are consistent with a slowing of poleward transport ofheat by the ocean currents.

The greenhouse effect
The temperature at any given point on the Earth’s surface is regulated by energy-exchange processes. The surface:•gains energy through absorption of solar energy and absorption of longwave radiation emitted downward by thegreenhouse gases of the atmosphere•loses energy through emission of longwave radiation, andflow of heat and latent energy to the atmosphere.

That is true on average for the Earth’s surface, but at any particular point, the situation might be slightly more complicated. As
we will see, in the warm tropical oceans, there is another energy
outflow due to heat transport by the ocean currents.
Apart from absorption of solar radiation (which is essentiallyconstant), the magnitude of each of the energy surface processes is governed by physical laws. The rate of energy flow in eachprocess varies with surface temperature, but each according toa different relationship. The Earth’s equilibrium global averagesurface temperature is achieved when the processes come into
long-term balance; in other words, when the absorption of solar
radiation is offset by the other energy exchange processes: emission of longwave radiation, the flow of heat and latent energy tothe atmosphere, and the absorption of longwave radiation fromthe atmosphere.
In the absence of greenhouse gases (including water vapour; in other words we are assuming Earth to be a waterlessplanet), no longwave radiation is emitted from the atmosphere2to be absorbed at the surface, nor is there any net flow of sensible and latent heat from the surface. Under these conditions, theequilibrium surface temperature is reached when the absorptionof solar radiation is equal to the surface emission of longwave
radiation. Without greenhouse gases the surface temperature
would be about −19°C.
However, Earth is of course a water planet, with the oceansmaking up 70% of the surface area and evaporation from thesurface providing a steady flow of latent energy – in the formof water vapour – to the atmosphere. Water vapour is the predominant greenhouse gas in the atmosphere and the primarysource of longwave radiation absorbed at the surface. The absorption of longwave emission from the greenhouse gases has
supplemented solar radiation, raising the global average surface
temperature such that the energy exchange processes are in balance at an equable surface temperature of about 15°C, about
34°C warmer than in the absence of water.
The importance of water vapour in regulating the greenhouse effect is evident from Table 1, which shows the changing
absorption of longwave radiation at the surface from the emissions by the greenhouse gases. In each column of the table, theatmospheric water vapour is the same and represents the average tropical value. It is the carbon dioxide concentration that increases from left to right, from no carbon dioxide, through values typical of the last glacial maximum (200 ppm), pre-industrial
levels (300 ppm), contemporary levels (400 ppm), and finally tovalues consistent with future unconstrained industrial emissions(600 ppm).
The approximately 7 W/m2 contribution to surface absorption by bring carbon dioxide up to pre-industrial levels represents
only 2% of the greenhouse effect. Increasing it to the 600 parts
per million (ppm) level expected with unabated emissions only
increases the latter figure by about 0.2%, from 369 W/m2 to
370 W/m2.
Climate history also points to the limited effect of carbon
dioxide on Earth’s temperature. At the time of the last glacial
maximum, 20,000 years ago, great ice sheets covered much ofNorth America and northwest Europe; sea level was about 130
metres lower than today. Over the next 10,000 years atmospheric
Table 1: Carbon dioxide’s minimal contribution to the greenhouse effect
Carbon dioxide (ppm)

0

200

300

400

600

Radiation emitted by the greenhouse gases and absorbed at the surface
Surface radiation (W/m2)
361.40368.01368.64
2
Increase (W/m )
—
6.61
0.63
Cumulative increase (W/m2)
—
6.61
7.24

369.260.62
7.86

370.21
0.95
8.81

Atmospheric water vapour levels are assumed constant at a level consistent with the tropics. Data from MODTRANS (MODTRAN
Infrared Light in the Atmosphere (uchicago.edu)).

3

carbon dioxide concentration increased from about 200 ppm to
300 ppm, and there were clearly large changes in temperature
over the same period – the great ice sheets largely melted, andthe sea surface rose to near its present level. However, the associated changes in radiation absorbed at the surface were rather
small (Table 1). Then, over the recent century of industrialisation,
carbon dioxide increased to more than 400 ppm, again with asmall associated increase in radiation absorbed at the surface.
However, the associated changes in global temperature havebeen difficult to detect. This all suggests that carbon dioxide has
only minimal climate impact and was not the cause of Earth’s deglaciation.

Equatorial ocean and lower atmosphere temperature
As noted above, most solar radiation hits the Earth in the tropics. It passes through the atmosphere and is absorbed at the surface. The solar radiation is absorbed into, and mixed through, thesurface layer of the oceans, which cover most of the Earth’s surface. The result is a lens of warm water near the surface, a tropical ocean heat reservoir often reaching more than 100 metres in
depth (Figure 1).
The temperature of the warm ocean lens is affected by fourenergy flows:••

absorption of shortwave radiation direct from the sun
absorption of longwave radiation from greenhouse gases in
the atmosphereloss of heat and latent energy to the atmosphereloss of heat via ocean currents.

••

Temperature across a depth
section of the equatorial Pacific
Ocean. (Papua New Guinea to theleft, South America to the right.)
Source: US NOAA Pacific Marine
Environment Laboratory.

0

Depth (hundreds of metres)

Figure 1: The heat
reservoir of the tropicalocean surface layer

1
2
3
4
5

140E

160E

10

4

180

160W
140W
Longitude

14
18
22
26
Water temperature (°C)

120W

30

100W

The surface waters are warmed by solar radiation, and temperatures vary with ocean circulations. The cooler waters overthe eastern equatorial Pacific Ocean are due to the ascending
cold interior waters associated with the global Thermohaline Circulation.
Over the last 40 years, the ocean surface has warmed byabout 0.4°C, implying that the balance of energy flows haschanged. But by which process? The flow of energy from the sun
is essentially constant, so that is quickly eliminated. However,after that opinions differ. The IPCC claims that the atmosphere,
warmed by increasing carbon dioxide concentrations, has heated the oceans below. However, this cannot be true, because, inthe tropics at least, the atmosphere is cooler than the ocean.
Varying carbon dioxide concentrations do have an influence;as they increase, the emission of radiation to the surface increases, warming the ocean surface. However, as noted in Table 1, theeffect over the tropics is small. In fact, it is possible to calculatethat the increase in carbon dioxide concentration, from 337  ppmto 411  ppm, only results in an increased energy flow of 0.3 W/m2.
That is far too little to explain an increased ocean temperature of
0.4°C, because the increased temperature in turn increases theflow of energy to the atmosphere by about 3.5 W/m2.
In other words, while a small amount of extra energy has
gone into the tropical ocean surface as a result of increased carbon dioxide concentrations, eight times as much has been escaping to the atmosphere. The absorption of additional radiationenergy from the change in carbon dioxide concentration is insufficient to support the rise in latent heat loss from the increase insurface temperature.
This leaves changes in ocean currents as the only plausible
explanation for the warming of the tropical reservoir. Importantly, this idea is supported by real-world evidence, such as the observed slowing of the Gulf Stream.

The tropical atmosphere
The above explanation for the warming of the tropical heat reservoir is consistent with other observed changes in the climate, notably atmospheric temperatures in the tropics and in the Arctic.
As noted previously, the greenhouse gases of the atmosphere emit more radiation than they absorb. This energy loss isoffset by a flow of heat and latent energy from the surface. The
tropical ocean heat reservoir is the primary source of this energy,
and the rate at which heat flows is regulated by the ocean surface temperature.
Over the tropics, the heat and latent energy from the ocean
surface remains in the lowest layer of the atmosphere below theclouds, and the trade winds draw it into the Equatorial Trough –a narrow band of latitudes close to the equator (the Doldrums,in common parlance). As the heat builds up in this region, deep
convection clouds form,5 and it is these that transport heat upwards into higher layers of the atmosphere, where the winds dis5

tribute the heat poleward.
The transport of heat upwards through this deep convection process creates a tight link between the temperature of thetropical atmosphere and that of the ocean surface below. Figure 2 shows the coherence of the atmosphere and ocean surface
temperatures. The correlation between the detrended records is0.86, albeit with a one- to two-month delay in the atmosphere’s
response.

Monthly temperature anomaly
for the equatorial ocean surface(Lat. 10°S to 10°N) and lower
atmosphere of the tropics (Lat.
20°S to 20°N). Data: ocean
temperature from the US NOAA
NCEP/DOE R2 data set; lower
atmosphere from University of
Alabama, Huntsville satellite
soundings.

1.2
0.8
Temperature anomaly (°C)

Figure 2: Equatorial
temperatures: ocean
surface and lower
atmosphere.

0.4
0

-0.4
-0.8

Ocean
Lower atmosphere

1980

1985

1990

1995

2000

2005

2010

2015

2020

The temperatures in both records change markedly fromyear to year – at times by up to 1°C. These changes are associatedwith changes in the ocean circulation associated with the El Niño
and La Niña events. Superimposed on this short-term variability,
there have been long-term warming trends of about 0.1°C per
decade in both records. The effect of the warming is two-fold:••the increased warmth in the tropical atmosphere is a sourceof additional energy, and increases the rate of heat transport to higher latitudes;
the warmer oceans increase the flow of latent energy to theatmosphere.

The latent energy is not immediately apparent, but will be seenin the warming at higher latitudes.

Arctic warming
Over middle and high latitudes, the emission of radiation to
space exceeds the absorption of solar radiation. However, temperatures over these higher latitudes are sustained by the inputof heat transported from the tropics in the atmospheric circulation. This process is at a maximum during the winter months,
when radiation loss to space is at its greatest, polar temperatures
are coldest, and the circulation is strongest.
Systematic monitoring of Earth’s temperature over the last
40 years has revealed regional and seasonal features associat6

Data: US NOAA NCEP/DOE R2
dataset.

1.4

10

1.2

5

1.0

0

0.8

-5

0.6

-10

0.4

-15

0.2

-20

0

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Ann.
ave

Mean temperature (°C)

Figure 3: Polar
temperatures respond to
the seasonally changing
atmospheric circulationand heat transport.

Trend (°C/decade)ed with warming. At equatorial latitudes, ocean surface and atmospheric temperatures have been warming at a rate of around
0.1°C per decade. Over the same period, surface temperaturesin middle and high latitudes of the northern hemisphere haveincreased at higher rates, averaging about 0.7°C per decade over
the Arctic.
Warming is greater over the Arctic than over the tropics because the additional latent energy exchanged from the tropicaloceans is transformed to heat over middle and high latitudes.
Moreover, the Arctic warming varies throughout the year, fromabout 0.4°C per decade in summer to 1.2°C per decade in colder
months (Figure 3). The fact that the warming has occurred predominantly during the cold winter half of the year, when the polar surface is largely in darkness, implies that it can only be theresult of heat transport from warmer latitudes.

-25

The warming spring and autumn months have extended thesummer snow melt period and the length of the growing season,
the latter contributing to the greening of the planet observed bysatellite.

Summary
The characteristics of recent climate change and its cause areclear. The tropical oceans have warmed, not as a result of additional atmospheric carbon dioxide but most likely because of areduction in the transport of heat, as ocean currents slow. The
warmer tropical oceans have raised the temperature of the tropical atmosphere in turn, in particular through the medium of deep
equatorial convection clouds. Additional energy flowing fromthe warmer tropical oceans has been transported by the winds
to enhance polar warming, especially in the winter months.
Put another way, recent warming is probably simply the result of a fluctuation in the ever-changing ocean circulation; carbon dioxide must be recognised as a very minor contributor tothe observed warming and one that is unlikely to prolong the7

warming trend beyond the peak generated by the naturaloceanic oscillations.
There has been much speculation that the recent warming trend will generate extreme weather events dangerous
to humankind. The evidence is not compelling. The greatest
warming has been over high northern latitudes, when temperatures are well below freezing. It will therefore be unlikely to have any appreciable impact on flora or fauna. Notwithstanding this, the impacts of both short- and medium-term
shifts in natural oscillations, such as El Niño and the Atlantic
Multidecadal Oscillation, will continue, and adequate preparedness remain essential.
The pattern of recent global warming underscores thevalidity of what meteorologists widely recognise: the oceans
are the vital inertial and thermal flywheels of the climate system. The corollary is, if one wants to control climate, it will
be necessary to control the oceans. Efforts to decarbonisein the hope of affecting global temperatures will be in vain.
GWPF invited the Royal Society and the Met Office to review thispaper, and to submit a response to be published as an appendix to it. No reply was received.

8

Notes

1. Earth’s radiation is radiant energy emitted by substances at temperatures typically found on Earth.
Earth radiation is also referred to as longwave radiation.
2. Solar radiation is energy emitted by the high temperatures of the Sun that reaches Earth. Solar radiation is also known as shortwave radiation.
3. ‘Greenhouse gases’ are those gases of the atmosphere (especially water vapour and carbon dioxide) that absorb and emit longwave radiation.
4. Although the amount of emission at high latitudes is lower than in the tropics.
5. Within the deep convection clouds the warm moist air from near the surface is lifted buoyantly
into the high atmosphere. As the air rises, it cools and the heat and latent energy are transformed topotential energy. As the air in the high atmosphere is taken poleward in the winds it subsides and thepotential energy is transformed to heat. It is this heat that is available to offset the radiation energy lossof the atmosphere.

9About the Global Warming Policy Foundation
People are naturally concerned about the environment, and want to see policies that protect it,
while enhancing human wellbeing; policies that don’t hurt, but help.
The Global Warming Policy Foundation (GWPF) is committed to the search for practical policies. Our aim is to raise standards in learning and understanding through rigorous research andanalysis, to help inform a balanced debate amongst the interested public and decision-makers.
We aim to create an educational platform on which common ground can be established, helping
to overcome polarisation and partisanship. We aim to promote a culture of debate, respect, and ahunger for knowledge.
Views expressed in the publications of the Global Warming Policy Foundation are those of theauthors, not those of the GWPF, its trustees, its Academic Advisory Council members or its directors.

THE GLOBAL WARMING POLICY FOUNDATION
Director
Honorary President
Benny Peiser
Lord Lawson
BOARD OF TRUSTEESDr Jerome Booth (Chairman)
Professor Peter Edwards
Kathy Gyngell
Professor Michael Kelly

Terence Mordaunt
Graham Stringer MP
Professor Fritz Vahrenholt

ACADEMIC ADVISORY COUNCIL

Professor Christopher Essex (Chairman)
Professor Wade Allison
Professor J. Ray Bates

Bill Kininmonth
Brian Leyland
Professor Richard Lindzen

Sir Ian Byatt
Dr John Constable
Professor Vincent Courtillot
Professor John Dewey
Professor Peter Dobson
Professor Samuel Furfari
Christian Gerondeau
Professor Larry Gould
Professor William Happer
Professor Ole Humlum
Professor Gautam Kalghatgi
Professor Terence Kealey

Professor Ross McKitrick
Professor Robert Mendelsohn
Professor Garth Paltridge
Professor Ian Plimer
Professor Gwythian Prins
Professor Paul Reiter
Professor Peter Ridd
Dr Matt Ridley
Sir Alan Rudge
Professor Nir Shaviv
Professor Henrik Svensmark
Dr David Whitehouse

GWPF NOTES
1Matt Ridley

A Lukewarmer's Ten Tests

2
3
4
5
6
7
8
9
10
11

Susan Crockford
Ross McKitrick
Andrew Montford
Andrew Montford
VariousMichael Kelly
David Whitehouse
Anthony Kelly
Susan Crockford
Andrew Montford

Ten Good Reasons Not to Worry About Polar Bears
An Evidence-based Approach to Pricing CO2 Emissions
Climate – Public Understanding and Policy Implications
Consensus? What Consensus?
The Geological Perspective of Global Warming: A Debate
Technology Introductions in the Context of Decarbonisation
Warming Interruptus: Causes for the Pause
Global Warming and the Poor
Healthy Polar Bears, Less Than Healthy Science
Fraud, Bias and Public Relations

12
13
14
15

Harry Wilkinson
Peter Lilley
Constable and Hughes
Patricia Adams

UK Shale Developments
The Helm Review and the Climate-Industrial Complex
Bubble or Babble?
The Road from Paris: China's Climate U-Turn

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17
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19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34

Mikko PaunioJohn Christy
Gordon Hughes
J. Ray Bates
Andrew Montford
Andrew Montford
David Whitehouse
Gautam Kalghatgi
John Constable
William M Briggs
Ross McKitrick
William M Briggs
J. Ray Bates
Susan Crockford
Michael Kelly
Michael Kelly
Andrew Montford
Peter Ridd
William Kininmonth

Save the Oceans: Stop Recycling Plastic
The Tropical Skies: Falsifying Climate Alarm
Who's the Patsy? Offshore Wind's High-stakes Poker Game
What Caused Hurricane Lorenzo?
Reducing Emissions Without Breaking the Bank
£3 Trillion and Counting: Net Zero and the National Ruin
The Next Solar Cycle and Why it Matters for Climate
The Battery Car Delusion
Who Are They Fooling? The UK Energy White Paper 2020
The Climate Blame Game: Are We Really Causing Extreme Weather?
Suboptimal Fingerprinting
How the IPCC Sees What Isn’t There
Polar Sea Ice and the Climate Catastrophe Narrative
The State of the Polar Bear 2021
Achieving Net Zero: A Report from a Putative Delivery Agency
Net Zero for New Zealand
Ten Things Everyone Should Know About Climate Models
The Good News on Coral Reefs
Rethinking the Greenhouse Effect

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