Els líders mundials consideren que les conclusions
del Grup Intergovernamental d'Experts sobre el Canvi Climàtic
(GIECC) són fiables; tant és així que les prediccions obtingudes
s'utilitzen per a formular lleis i polítiques. No obstant això, el
GIECC no ha sobreestimat el canvi climàtic, sinó que ha subestimat
la gravetat de l'escalfament global, principalment perquè
ha prestat massa atenció a les emissions de diòxid de carboni
i no la suficient a la resposta de la Terra. Al llarg dels últims
quaranta-quatre anys he treballat observant la Terra d'una manera
diferent, com un sistema dinàmic que regula activament el
clima i la composició atmosfèrica per mantenir el planeta habitable.
La Terra no accepta passivament l'acció humana. Respon
al canvi climàtic d'una manera molt més mortífera que el
petit canvi que estem provocant. La teoria de Gaia sosté que el
sistema Terra pot actuar com un amplificador i les petites modificacions,
ja siguin cap a la calor o al fred, s'intensifiquen, fet
que podria ser la causa dels canvis erràtics de temperatura. En
aquest article intentaré demostrar que aturar el canvi climàtic
pot ser més difícil del que creuen els governs. La nostra tasca,
en cas que l'escalfament global continuï, és adaptar-nos a la
nova situació i preparar-nos per a sobreviure.The findings of the Intergovernmental Panel on Climate
Change (IPCC) are taken by world leaders as authoritative,
so much so that their predictions are used to frame legislation
and policy. However, the IPCC has not overestimated
climate change, they have, instead, underestimated the severity
of global heating mainly because they paid too much attention
to our emissions of carbon dioxide and not enough to the
Earths response. For the past 44 years I have worked on a different
way of looking at the Earth, seeing it as a dynamic system
that actively regulates the climate and the atmospheric
composition to keep the planet habitable. The Earth does not
passively accept what we do to it. It responds to climate
change and that response is far more deadly than the small
change that we are making. Gaia theory teaches that the Earth
system can act as an amplifier and small changes either to heat
or cold are intensified and this could be the cause of the erratic
shifts of temperature. In this article I will try to show that stopping
climate change may be more difficult than our governments
believe. Our task, should global heating continue, is to
adapt and prepare to survive

Lovelock, James E.

Revistes Catalanes amb Accés Obert

CONTRIBUTIONS to SCIENCE, 7 (1): 17–20 (2011)
Institut d’Estudis Catalans, Barcelona
DOI: 10.2436/20.7010.01.103  ISSN: 1575­6343 
www.cat-science.cat
What	happened	to	global	warming?
You must be wondering what has happened to global warm­
ing. The average temperature has barely changed during the 
last ten years. Does this mean that global warming is no more 
than a green nightmare and we need no longer feel guilty about 
our carbon emissions? Sadly, the facts do not justify such a 
conclusion. If we want a more authoritative account of the cli­
mate we still must turn to the Intergovernmental Panel on Cli­
mate Change, the IPCC.
It is made up from over 1000 of the world best climate scien­
tists and importantly they regard climate change as real, and 
potentially deadly. Their findings are taken by world leaders as 
authoritative, so much so that their predictions are used to 
frame legislation and policy looking 40 or more years into the 
future. European governments argue for massive and expen­
sive action now if we are to avoid damaging climate change. 
Governments worldwide seem to assume that merely reducing 
carbon emissions will stabilize or even reverse climate change. 
In this article, which is about the Earth and its climate, I will try 
to show that stopping climate change may be more difficult 
than our governments believe.
The IPCC has not overestimated climate change, they have, 
instead, underestimated the severity of global heating mainly 
Resum.	Els líders mundials consideren que les conclusions 
del Grup Intergovernamental d’Experts sobre el Canvi Climàtic 
(GIECC) són fiables; tant és així que les prediccions obtingudes 
s’utilitzen per a formular lleis i polítiques. No obstant això, el 
GIECC no ha sobreestimat el canvi climàtic, sinó que ha sub­
estimat la gravetat de l’escalfament global, principalment per­
què ha prestat massa atenció a les emissions de diòxid de car­
boni i no la suficient a la resposta de la Terra. Al llarg dels últims 
quaranta­quatre anys he treballat observant la Terra d’una ma­
nera diferent, com un sistema dinàmic que regula activament el 
clima i la composició atmosfèrica per mantenir el planeta habi­
table. La Terra no accepta passivament l’acció humana. Res­
pon al canvi climàtic d’una manera molt més mortífera que el 
petit canvi que estem provocant. La teoria de Gaia sosté que el 
sistema Terra pot actuar com un amplificador i les petites mo­
dificacions, ja siguin cap a la calor o al fred, s’intensifiquen, fet 
que podria ser la causa dels canvis erràtics de temperatura. En 
aquest article intentaré demostrar que aturar el canvi climàtic 
pot ser més difícil del que creuen els governs. La nostra tasca, 
en cas que l’escalfament global continuï, és adaptar­nos a la 
nova situació i preparar­nos per a sobreviure.
Paraules	clau:	teoria de	Gaia ∙ canvi climàtic ∙ escalfament 
global ∙ Grup Intergovernamental d’Experts sobre el Canvi 
Climàtic (GIECC) ∙ ciència del sistema terrestre
Summary.	The findings of the Intergovernmental Panel on Cli­
mate Change (IPCC) are taken by world leaders as authorita­
tive, so much so that their predictions are used to frame legisla­
tion and policy. However, the IPCC has not overestimated 
climate change, they have, instead, underestimated the sever­
ity of global heating mainly because they paid too much atten­
tion to our emissions of carbon dioxide and not enough to the 
Earth’s response. For the past 44 years I have worked on a dif­
ferent way of looking at the Earth, seeing it as a dynamic sys­
tem that actively regulates the climate and the atmospheric 
composition to keep the planet habitable. The Earth does not 
passively accept what we do to it. It responds to climate 
change and that response is far more deadly than the small 
change that we are making. Gaia theory teaches that the Earth 
system can act as an amplifier and small changes either to heat 
or cold are intensified and this could be the cause of the erratic 
shifts of temperature. In this article I will try to show that stop­
ping climate change may be more difficult than our govern­
ments believe. Our task, should global heating continue, is to 
adapt and prepare to survive. 
Keywords: Gaia theory ∙ climate change ∙ global warming ∙ 
Intergovernmental Panel on Climate Change (IPCC) ∙ Earth 
System Science
* Based on the lecture given by the author at the Auditorium of Galicia, 
Santiago de Compostela, on 6 October 2009. James E. Lovelock was 
the recipient of the Fonseca Prize of Scientific Popularization 2009.
Correspondence: J.E. Lovelock, Green Templeton College, Univer­ 
sity of Oxford, Woodstock Road, Oxford OX2 6HG, United Kingdom. 
Tel. +44­(0)1865274770. Fax + 44­(0)1865274796. E­mail: 
jesjl@daisyworld.org
Climate	change	on	a	live	Earth*
James	E.	Lovelock
Green Templeton College, University of Oxford, Oxford
Fonseca Prize Lecture 2009
001-092 Contributions 7-1.indd   17 11/11/2011   14:04:28
18  Contrib. Sci. 7 (1), 2011 Lovelock
because they paid too much attention to our emissions of car­
bon dioxide and not enough to the Earth’s response. The Earth 
does not passively accept what we do to it. It responds to cli­
mate change and that response is far more deadly than the 
small change that we are making. Because the Earth’s re­
sponses are happening in the deserts, the forests, in the 
ocean, and at the poles—all far away from the cities—we do 
not notice them. But to me they bring an apocalyptic view of 
the future because I see 7 to 8 billion of humans faced with ever 
diminishing supplies of food and water in an increasingly intol­
erable climate. 
You may well ask how we scientists have let this potentially 
disastrous future steal up on us unaware. There are three main 
reasons. First was our success in solving the problem of strat­
ospheric ozone depletion. This gave atmospheric scientists 
false confidence in their ability to deal with the far greater and 
more complex danger of global heating. Second is the division 
of Science into almost unconnected specialities. Climate sci­
ence is almost wholly about atmospheric physics and chemis­
try and ecological science is almost entirely about the biology 
of living organisms. Neither of these groups of scientists is yet 
ready to embrace Gaia theory which offers a unified Earth sci­
ence. Unfortunately for us the Earth is not so divided and so 
long as we treat it as two separate entities, the geosphere for 
the material Earth and the biosphere for life, we will fail to un­
derstand our planet. 
The third reason for science to have been wrong footed is the 
old division between theory and practice. The ever growing 
power of computers has made it easier to build apparently real­
istic theoretical simulations of our planet, and its climate. It be­
comes too tempting to believe that the computer model is the 
real world and that the hard down to earth effort of gathering 
data on the polar glaciers or in the tropical forests is less needed. 
We should have been warned. The first inexcusable error 
occurred when it was realised that ozone in the stratosphere 
was in danger of destruction by the chlorofluorocarbons (CFCs) 
we used in our spray cans and refrigerators. In the 1980s theo­
rists and modellers of stratospheric ozone depletion were so 
sure that their models were true that they ignored data about 
CFC abundance in the atmosphere. I know this because I was 
one of the few scientists who were making the measurements. 
They also ignored data about ozone in the stratosphere. Earth 
orbiting satellites first saw that ozone was being destroyed over 
the South Pole but this was not predicted by theory or models. 
The theorists were so sure that they were right that they in­
structed the satellites to ignore low values of ozone and several 
years passed before we realised that ozone was being de­
stroyed. It was not until two scientists at an Antarctic base 
looked up into the sky with a simple spectrometer that the hole 
in the ozone layer was seen and only then did we realise how 
serious ozone depletion was. Now another deadly hole has ap­
peared, this time in the floating ice of the Arctic Ocean, and 
much sooner than the models forecast. Yet again the theorists 
are failing to forecast what is actually happening in the real 
world. The lesson has not been learnt. 
If the climate models are unreliable how can we be sure 
about the climate of ten years from now still less the end of the 
century? The simple answer is that we can’t. Figure 1, for ex­
ample, shows a comparison between the measured sea level 
of the past two decades and what the IPCC forecast.
Sea	level:	Earth’s	own	thermometer
If you really want to take the temperature of the Earth and see if 
its complaint of global heat is real, ignore air and land surface 
temperatures, these fluctuate from year to year and place to 
place. Look instead at the Earth’s own thermometer, the level 
of the sea. There are only two important causes of sea level 
rise. The expansion of the ocean as its temperature rises and 
the addition of water as ice on the land melts. Because the 
oceans are confluent over the surface, the sea level is repre­
sentative for the whole ocean and is a realistic Earth thermom­
eter. More than 70% of the Earth’s surface is ocean and it is on 
average about 4 kilometres deep. The capacity to hold warmth 
of this large mass of water is about 800 times greater than that 
of the atmosphere. So long as the sea level keeps rising global 
heating is happening (Fig. 2).
Fig.	1. Comparison between measured median sea level change and 
IPCC forecast (1993–2005).
Anomaly from 1978–2000 mean
Year
Ic
e 
A
no
m
al
y 
(m
ill
io
n 
sq
ua
re
 k
m
) 2
1
0
-1
-2
19
78
19
79
19
80
19
81
19
82
19
83
19
84
19
85
19
86
19
87
19
88
19
89
19
90
19
91
19
92
19
93
19
94
19
95
19
96
19
97
19
98
19
99
20
00
20
01
20
02
20
03
20
04
20
05
20
06
20
07
20
08
Fig.	2. Northern hemisphere sea ice anomaly. Anomaly from 1978–
2000 mean.
001-092 Contributions 7-1.indd   18 11/11/2011   14:04:28
Climate change on a live Earth Contrib. Sci. 7 (1), 2011  19
The extra heat absorbed by dark ocean water as the floating 
ice melts is causing an acceleration of system driven heating 
whose total will soon or already be greater than that from all of 
the pollution CO2 that we have so far added. If it continues 
there will soon be an outburst of methane and other green­
house gases from the melting arctic permafrost. The Earth is 
not merely responding, it is now driving global heating.
Gaia	theory	and	climate	history
For the past 44 years I have worked on a different way of look­
ing at the Earth, seeing it as a dynamic system that actively 
regulates the climate and the atmospheric composition to keep 
the planet habitable. This is Gaia theory. It is now accepted as 
mainstream science and often called Earth System science; 
but although accepted in principle there has not yet been time 
to include the theory in the separated Life and Earth sciences 
which still continue to view the Earth from within either Life or 
Earth science. 
Gaia theory fits better with the climate history of the Earth 
than does conventional science. The historical record suggests 
that the Earth has at least two stable climate states, one about 
6 degrees hotter than now and one about 5 degrees colder 
than now. Geologists call these two states, the greenhouse 
and the icehouse. If we look back to climate history about 
14,000 years ago we see from Greenland ice core records how 
the real climate moves from one state to another (Fig. 3).
This irregular course of the world’s temperature is very dif­
ferent from the smooth curves of the IPCC’s models. Gaia the­
ory teaches that the Earth system can act as an amplifier and 
small changes either to heat or cold are intensified and this 
could be the cause of the erratic shifts of temperature.
I find it extraordinary that climate scientists could have put 
their names to predictions as far away as the end of the century 
and in the face of such great uncertainties. I know scientists of 
the IPCC and some are personal friends. I know that they are 
wise, competent and principled. So what made them persist 
with what may be the wrong kind of climate model and let their 
forecasts be used to frame policy? One answer may be that 
they had no option. Having persuaded governments that large 
expensive modelling centres, the battleships of the climate 
war, were needed. They just had to sail in them and hope for 
the best. 
So	what	is	the	prognosis?
If we assume that the IPCC is more or less right about the next 
thirty years then they forecast a torrid world by 2040 with an 
average summer in north temperate regions as hot as the sum­
mer of 2003 in Europe when over 30,000 died from heat. By 
then we may cool ourselves with air conditioning and learn to 
live in a climate no worse than that of Bagdad now. But without 
extensive irrigation the plants will die and both farming and nat­
ural ecosystems will be replaced by scrub and desert. What will 
there be to eat? The same dire changes could affect the rest of 
the world and I can envisage Americans migrating into Canada 
and the Chinese to Africa or Siberia. But will there be enough 
food for them all? Much of Europe will be arid desert land that 
will depend on Northern Europe and islands like the UK and 
Ireland for food. Heat alone will not be the main problem. What 
will be is too much or too little water from catastrophic floods or 
prolonged drought.
That is what the IPCC forecasts. Earth history and Gaia the­
ory both suggest that climate change can be faster and more 
severe and can fluctuate between hot and cool before making 
its final move to the stable state, about 5 degrees hotter than 
now. As the hot state is approached stopping emissions will 
make little difference to the dire course of events and could 
even make matters worse. Because we are uncertain about 
the climate future we can only guess at geographic and demo­
graphic change. What can be said is that the north temperate 
and arctic regions that include Canada and Siberia will be fa­
voured. So will oceanic strips along the continents like here in 
Galicia and places such as the British Isles, and New Zealand. 
Many tropical islands may also be habitable and on the conti­
nents there will be oasis areas and habitable land along rivers.
The most vulnerable nations are those of the Indian subcon­
tinent and China. The Indian group of nations will suffer both 
inundation and drought. A great loss of life seems almost inevi­
table. China is not in a much more favourable position than In­
dia and Pakistan. In these nations and mainland Europe, popu­
lation excess is at least as large a factor as climate change. 
Some of the nations less vulnerable to climate change are un­
fortunately densely populated but will increasingly become the 
destination for refugees. The large and agonizing problem will 
be restricting population to the number that can be fed other­
wise starvation will achieve the same result. 
Governments should not assume that their remedies for glo­
bal heating—carbon capture and storage, renewable energy 
and biofuel—will halt or even slow global heating, they are all 
profitable but that is not enough. The fact that the Earth now 
has five or more sub­systems each adding its own heat sug­
Earth age (thousands of years before present)
Te
m
p
er
at
ur
e 
va
ria
tio
n 
(º
C
)
15
-6
-4
-2
0
10 5 0
Fig.	3. Global mean temperature.
001-092 Contributions 7-1.indd   19 11/11/2011   14:04:28
20  Contrib. Sci. 7 (1), 2011 Lovelock
gests that we are committed to move to a hotter state. Our 
task, should global heating continue, is to adapt and prepare to 
survive and this alone may be an exhausting task. Gaia has 
survived far worse insults than industrialised humans and will 
almost certainly save itself, we are the ones in danger, not the 
Earth.
We are a tough species and have survived seven major cli­
mate crises in the past million years—by this I mean the violent 
move from ice age to interglacial. These we now know hap­
pened about every 140,000 years, but the number of survivors 
may have been as low as 2000 after one of these catastro­
phes. We won’t be made extinct by global heating but we may 
be cut back to a billion or less. We have to survive global heat­
ing and hope that the stresses it imposes will encourage the 
natural selection of a more capable form of human. We truly 
have to concentrate on saving ourselves; it is hubris to think 
that we can ‘save the planet.’
Perhaps the saddest thing is that if we fail and humans go 
extinct, The Earth will lose as much or more than we do. Not 
only will wildlife and whole ecosystems vanish, but in human 
civilization the planet has a precious resource. We are not 
merely a disease; we are through our intelligence and commu­
nication the planetary equivalent of a nervous system. We 
should not feel guilty; in the Earth’s history there have been 
other organisms that in their early development wreaked havoc 
yet in time became vital components of Gaia. Photosynthesis­
ers that released oxygen must have been far worse polluters 
than we are. Yet over the years life adapted and then made use 
of this reactive gas to empower animal life and us.
Gaia has had to wait 3.5 billion years for natural selection to 
choose an intelligent partly social animal species. The photo­
synthesisers had to wait a long time before they became trees 
and so we humans have to be patient while evolution selects 
us to become an integrated part of an intelligent planet, but 
what a future for humans that would be.
Professor James E. Lovelock, author of Gaia theory and 
recipient of the Fonseca Prize of Scientific Popularization 
2009, pronounced the lecture entitled “Climate change on 
a live Earth” for the award ceremony, on 6 October 2009 
in Santiago de Compostela. 
The Consortium of Santiago and the University of Santia­
go de Compostela, aware of the importance of the trans­
fer of knowledge and society’s science education needs, 
agreed in 2006 to create the ConCiencia Programme to 
invite the greatest intellects of the international scientific 
community to transmit their ideas in a city which is a sym­
bol of culture and knowledge. Under the auspices of the 
ConCiencia Programme, the Fonseca Prize for Scientific 
Popularization was created with the aim of promoting the 
transfer of knowledge to the society. The award recogniz­
es those individuals who have had a distinguished career 
in the field of scientific communication or are a public ref­
erence in stimulating and promoting the general interest in 
scientific and technical knowledge. Other recipients of this 
award have been Professor Stephen W. Hawking (2008), 
Sir David Attenborough (2010) and Sir Roger Penrose 
(2011). More information: www.usc.es/conciencia.
001-092 Contributions 7-1.indd   20 11/11/2011   14:04:28


Climate change on a live Earth

Els l&iacute;ders mundials consideren que les conclusions del Grup Intergovernamental d'Experts sobre el Canvi Clim&agrave;tic (GIECC) s&oacute;n fiables; tant &eacute;s aix&iacute; que les prediccions obtingudes s'utilitzen per a formular lleis i pol&iacute;tiques. No obstant aix&ograve;, el GIECC no ha sobreestimat el canvi clim&agrave;tic, sin&oacute; que ha subestimat la gravetat de l'escalfament global, principalment perqu&egrave; ha prestat massa atenci&oacute; a les emissions de di&ograve;xid de carboni i no la suficient a la resposta de la Terra. Al llarg dels &uacute;ltims quaranta-quatre anys he treballat observant la Terra d'una manera diferent, com un sistema din&agrave;mic que regula activament el clima i la composici&oacute; atmosf&egrave;rica per mantenir el planeta habitable. La Terra no accepta passivament l'acci&oacute; humana. Respon al canvi clim&agrave;tic d'una manera molt m&eacute;s mort&iacute;fera que el petit canvi que estem provocant. La teoria de Gaia sost&eacute; que el sistema Terra pot actuar com un amplificador i les petites modificacions, ja siguin cap a la calor o al fred, s'intensifiquen, fet que podria ser la causa dels canvis err&agrave;tics de temperatura. En aquest article intentar&eacute; demostrar que aturar el canvi clim&agrave;tic pot ser m&eacute;s dif&iacute;cil del que creuen els governs. La nostra tasca, en cas que l'escalfament global continu&iuml;, &eacute;s adaptar-nos a la nova situaci&oacute; i preparar-nos per a sobreviure.The findings of the Intergovernmental Panel on Climate&nbsp;Change (IPCC) are taken by world leaders as authoritative,&nbsp;so much so that their predictions are used to frame legislation&nbsp;and policy. However, the IPCC has not overestimated&nbsp;climate change, they have, instead, underestimated the severity&nbsp;of global heating mainly because they paid too much attention&nbsp;to our emissions of carbon dioxide and not enough to the&nbsp;Earth's response. For the past 44 years I have worked on a differentway of looking at the Earth, seeing it as a dynamic system&nbsp;that actively regulates the climate and the atmospheric&nbsp;composition to keep the planet habitable. The Earth does not&nbsp;passively accept what we do to it. It responds to climate&nbsp;change and that response is far more deadly than the small&nbsp;change that we are making. Gaia theory teaches that the Earthsystem can act as an amplifier and small changes either to heat&nbsp;or cold are intensified and this could be the cause of the erratic&nbsp;shifts of temperature. In this article I will try to show that stopping&nbsp;climate change may be more difficult than our governments&nbsp;believe. Our task, should global heating continue, is to&nbsp;adapt and prepare to survive

Hemeroteca Cientifica Catalana

CONTRIBUTIONS to SCIENCE, 7 (1): 17–20 (2011)Institut d’Estudis Catalans, BarcelonaDOI: 10.2436/20.7010.01.103  ISSN: 1575­6343 www.cat-science.catWhat	happened	to	global	warming?You must be wondering what has happened to global warm­ing. The average temperature has barely changed during the last ten years. Does this mean that global warming is no more than a green nightmare and we need no longer feel guilty about our carbon emissions? Sadly, the facts do not justify such a conclusion. If we want a more authoritative account of the cli­mate we still must turn to the Intergovernmental Panel on Cli­mate Change, the IPCC.It is made up from over 1000 of the world best climate scien­tists and importantly they regard climate change as real, and potentially deadly. Their findings are taken by world leaders as authoritative, so much so that their predictions are used to frame legislation and policy looking 40 or more years into the future. European governments argue for massive and expen­sive action now if we are to avoid damaging climate change. Governments worldwide seem to assume that merely reducing carbon emissions will stabilize or even reverse climate change. In this article, which is about the Earth and its climate, I will try to show that stopping climate change may be more difficult than our governments believe.The IPCC has not overestimated climate change, they have, instead, underestimated the severity of global heating mainly Resum.	 Els líders mundials consideren que les conclusions del Grup Intergovernamental d’Experts sobre el Canvi Climàtic (GIECC) són fiables; tant és així que les prediccions obtingudes s’utilitzen per a formular lleis i polítiques. No obstant això, el GIECC no ha sobreestimat el canvi climàtic, sinó que ha sub­estimat la gravetat de l’escalfament global, principalment per­què ha prestat massa atenció a les emissions de diòxid de car­boni i no la suficient a la resposta de la Terra. Al llarg dels últims quaranta­quatre anys he treballat observant la Terra d’una ma­nera diferent, com un sistema dinàmic que regula activament el clima i la composició atmosfèrica per mantenir el planeta habi­table. La Terra no accepta passivament l’acció humana. Res­pon al canvi climàtic d’una manera molt més mortífera que el petit canvi que estem provocant. La teoria de Gaia sosté que el sistema Terra pot actuar com un amplificador i les petites mo­dificacions, ja siguin cap a la calor o al fred, s’intensifiquen, fet que podria ser la causa dels canvis erràtics de temperatura. En aquest article intentaré demostrar que aturar el canvi climàtic pot ser més difícil del que creuen els governs. La nostra tasca, en cas que l’escalfament global continuï, és adaptar­nos a la nova situació i preparar­nos per a sobreviure.Paraules	clau:	teoria de	Gaia ∙ canvi climàtic ∙ escalfament global ∙ Grup Intergovernamental d’Experts sobre el Canvi Climàtic (GIECC) ∙ ciència del sistema terrestreSummary.	The findings of the Intergovernmental Panel on Cli­mate Change (IPCC) are taken by world leaders as authorita­tive, so much so that their predictions are used to frame legisla­tion and policy. However, the IPCC has not overestimated climate change, they have, instead, underestimated the sever­ity of global heating mainly because they paid too much atten­tion to our emissions of carbon dioxide and not enough to the Earth’s response. For the past 44 years I have worked on a dif­ferent way of looking at the Earth, seeing it as a dynamic sys­tem that actively regulates the climate and the atmospheric composition to keep the planet habitable. The Earth does not passively accept what we do to it. It responds to climate change and that response is far more deadly than the small change that we are making. Gaia theory teaches that the Earth system can act as an amplifier and small changes either to heat or cold are intensified and this could be the cause of the erratic shifts of temperature. In this article I will try to show that stop­ping climate change may be more difficult than our govern­ments believe. Our task, should global heating continue, is to adapt and prepare to survive. Keywords: Gaia theory ∙ climate change ∙ global warming ∙ Intergovernmental Panel on Climate Change (IPCC) ∙ Earth System Science* Based on the lecture given by the author at the Auditorium of Galicia, Santiago de Compostela, on 6 October 2009. James E. Lovelock was the recipient of the Fonseca Prize of Scientific Popularization 2009.Correspondence: J.E. Lovelock, Green Templeton College, Univer­ sity of Oxford, Woodstock Road, Oxford OX2 6HG, United Kingdom. Tel. +44­(0)1865274770. Fax + 44­(0)1865274796. E­mail: jesjl@daisyworld.orgClimate	change	on	a	live	Earth*James	E.	LovelockGreen Templeton College, University of Oxford, OxfordFonseca Prize Lecture 2009001-092 Contributions 7-1.indd   17 11/11/2011   14:04:2818  Contrib. Sci. 7 (1), 2011 Lovelockbecause they paid too much attention to our emissions of car­bon dioxide and not enough to the Earth’s response. The Earth does not passively accept what we do to it. It responds to cli­mate change and that response is far more deadly than the small change that we are making. Because the Earth’s re­sponses are happening in the deserts, the forests, in the ocean, and at the poles—all far away from the cities—we do not notice them. But to me they bring an apocalyptic view of the future because I see 7 to 8 billion of humans faced with ever diminishing supplies of food and water in an increasingly intol­erable climate. You may well ask how we scientists have let this potentially disastrous future steal up on us unaware. There are three main reasons. First was our success in solving the problem of strat­ospheric ozone depletion. This gave atmospheric scientists false confidence in their ability to deal with the far greater and more complex danger of global heating. Second is the division of Science into almost unconnected specialities. Climate sci­ence is almost wholly about atmospheric physics and chemis­try and ecological science is almost entirely about the biology of living organisms. Neither of these groups of scientists is yet ready to embrace Gaia theory which offers a unified Earth sci­ence. Unfortunately for us the Earth is not so divided and so long as we treat it as two separate entities, the geosphere for the material Earth and the biosphere for life, we will fail to un­derstand our planet. The third reason for science to have been wrong footed is the old division between theory and practice. The ever growing power of computers has made it easier to build apparently real­istic theoretical simulations of our planet, and its climate. It be­comes too tempting to believe that the computer model is the real world and that the hard down to earth effort of gathering data on the polar glaciers or in the tropical forests is less needed. We should have been warned. The first inexcusable error occurred when it was realised that ozone in the stratosphere was in danger of destruction by the chlorofluorocarbons (CFCs) we used in our spray cans and refrigerators. In the 1980s theo­rists and modellers of stratospheric ozone depletion were so sure that their models were true that they ignored data about CFC abundance in the atmosphere. I know this because I was one of the few scientists who were making the measurements. They also ignored data about ozone in the stratosphere. Earth orbiting satellites first saw that ozone was being destroyed over the South Pole but this was not predicted by theory or models. The theorists were so sure that they were right that they in­structed the satellites to ignore low values of ozone and several years passed before we realised that ozone was being de­stroyed. It was not until two scientists at an Antarctic base looked up into the sky with a simple spectrometer that the hole in the ozone layer was seen and only then did we realise how serious ozone depletion was. Now another deadly hole has ap­peared, this time in the floating ice of the Arctic Ocean, and much sooner than the models forecast. Yet again the theorists are failing to forecast what is actually happening in the real world. The lesson has not been learnt. If the climate models are unreliable how can we be sure about the climate of ten years from now still less the end of the century? The simple answer is that we can’t. Figure 1, for ex­ample, shows a comparison between the measured sea level of the past two decades and what the IPCC forecast.Sea	level:	Earth’s	own	thermometerIf you really want to take the temperature of the Earth and see if its complaint of global heat is real, ignore air and land surface temperatures, these fluctuate from year to year and place to place. Look instead at the Earth’s own thermometer, the level of the sea. There are only two important causes of sea level rise. The expansion of the ocean as its temperature rises and the addition of water as ice on the land melts. Because the oceans are confluent over the surface, the sea level is repre­sentative for the whole ocean and is a realistic Earth thermom­eter. More than 70% of the Earth’s surface is ocean and it is on average about 4 kilometres deep. The capacity to hold warmth of this large mass of water is about 800 times greater than that of the atmosphere. So long as the sea level keeps rising global heating is happening (Fig. 2).Fig.	1. Comparison between measured median sea level change and IPCC forecast (1993–2005).Anomaly from 1978–2000 meanYearIce Anomaly (million square km) 210-1-21978197919801981198219831984198519861987198819891990199119921993199419951996199719981999200020012002200320042005200620072008Fig.	2. Northern hemisphere sea ice anomaly. Anomaly from 1978–2000 mean.001-092 Contributions 7-1.indd   18 11/11/2011   14:04:28Climate change on a live Earth Contrib. Sci. 7 (1), 2011  19The extra heat absorbed by dark ocean water as the floating ice melts is causing an acceleration of system driven heating whose total will soon or already be greater than that from all of the pollution CO2 that we have so far added. If it continues there will soon be an outburst of methane and other green­house gases from the melting arctic permafrost. The Earth is not merely responding, it is now driving global heating.Gaia	theory	and	climate	historyFor the past 44 years I have worked on a different way of look­ing at the Earth, seeing it as a dynamic system that actively regulates the climate and the atmospheric composition to keep the planet habitable. This is Gaia theory. It is now accepted as mainstream science and often called Earth System science; but although accepted in principle there has not yet been time to include the theory in the separated Life and Earth sciences which still continue to view the Earth from within either Life or Earth science. Gaia theory fits better with the climate history of the Earth than does conventional science. The historical record suggests that the Earth has at least two stable climate states, one about 6 degrees hotter than now and one about 5 degrees colder than now. Geologists call these two states, the greenhouse and the icehouse. If we look back to climate history about 14,000 years ago we see from Greenland ice core records how the real climate moves from one state to another (Fig. 3).This irregular course of the world’s temperature is very dif­ferent from the smooth curves of the IPCC’s models. Gaia the­ory teaches that the Earth system can act as an amplifier and small changes either to heat or cold are intensified and this could be the cause of the erratic shifts of temperature.I find it extraordinary that climate scientists could have put their names to predictions as far away as the end of the century and in the face of such great uncertainties. I know scientists of the IPCC and some are personal friends. I know that they are wise, competent and principled. So what made them persist with what may be the wrong kind of climate model and let their forecasts be used to frame policy? One answer may be that they had no option. Having persuaded governments that large expensive modelling centres, the battleships of the climate war, were needed. They just had to sail in them and hope for the best. So	what	is	the	prognosis?If we assume that the IPCC is more or less right about the next thirty years then they forecast a torrid world by 2040 with an average summer in north temperate regions as hot as the sum­mer of 2003 in Europe when over 30,000 died from heat. By then we may cool ourselves with air conditioning and learn to live in a climate no worse than that of Bagdad now. But without extensive irrigation the plants will die and both farming and nat­ural ecosystems will be replaced by scrub and desert. What will there be to eat? The same dire changes could affect the rest of the world and I can envisage Americans migrating into Canada and the Chinese to Africa or Siberia. But will there be enough food for them all? Much of Europe will be arid desert land that will depend on Northern Europe and islands like the UK and Ireland for food. Heat alone will not be the main problem. What will be is too much or too little water from catastrophic floods or prolonged drought.That is what the IPCC forecasts. Earth history and Gaia the­ory both suggest that climate change can be faster and more severe and can fluctuate between hot and cool before making its final move to the stable state, about 5 degrees hotter than now. As the hot state is approached stopping emissions will make little difference to the dire course of events and could even make matters worse. Because we are uncertain about the climate future we can only guess at geographic and demo­graphic change. What can be said is that the north temperate and arctic regions that include Canada and Siberia will be fa­voured. So will oceanic strips along the continents like here in Galicia and places such as the British Isles, and New Zealand. Many tropical islands may also be habitable and on the conti­nents there will be oasis areas and habitable land along rivers.The most vulnerable nations are those of the Indian subcon­tinent and China. The Indian group of nations will suffer both inundation and drought. A great loss of life seems almost inevi­table. China is not in a much more favourable position than In­dia and Pakistan. In these nations and mainland Europe, popu­lation excess is at least as large a factor as climate change. Some of the nations less vulnerable to climate change are un­fortunately densely populated but will increasingly become the destination for refugees. The large and agonizing problem will be restricting population to the number that can be fed other­wise starvation will achieve the same result. Governments should not assume that their remedies for glo­bal heating—carbon capture and storage, renewable energy and biofuel—will halt or even slow global heating, they are all profitable but that is not enough. The fact that the Earth now has five or more sub­systems each adding its own heat sug­Earth age (thousands of years before present)Temperature variation (ºC)15-6-4-2010 5 0Fig.	3. Global mean temperature.001-092 Contributions 7-1.indd   19 11/11/2011   14:04:2820  Contrib. Sci. 7 (1), 2011 Lovelockgests that we are committed to move to a hotter state. Our task, should global heating continue, is to adapt and prepare to survive and this alone may be an exhausting task. Gaia has survived far worse insults than industrialised humans and will almost certainly save itself, we are the ones in danger, not the Earth.We are a tough species and have survived seven major cli­mate crises in the past million years—by this I mean the violent move from ice age to interglacial. These we now know hap­pened about every 140,000 years, but the number of survivors may have been as low as 2000 after one of these catastro­phes. We won’t be made extinct by global heating but we may be cut back to a billion or less. We have to survive global heat­ing and hope that the stresses it imposes will encourage the natural selection of a more capable form of human. We truly have to concentrate on saving ourselves; it is hubris to think that we can ‘save the planet.’Perhaps the saddest thing is that if we fail and humans go extinct, The Earth will lose as much or more than we do. Not only will wildlife and whole ecosystems vanish, but in human civilization the planet has a precious resource. We are not merely a disease; we are through our intelligence and commu­nication the planetary equivalent of a nervous system. We should not feel guilty; in the Earth’s history there have been other organisms that in their early development wreaked havoc yet in time became vital components of Gaia. Photosynthesis­ers that released oxygen must have been far worse polluters than we are. Yet over the years life adapted and then made use of this reactive gas to empower animal life and us.Gaia has had to wait 3.5 billion years for natural selection to choose an intelligent partly social animal species. The photo­synthesisers had to wait a long time before they became trees and so we humans have to be patient while evolution selects us to become an integrated part of an intelligent planet, but what a future for humans that would be.Professor James E. Lovelock, author of Gaia theory and recipient of the Fonseca Prize of Scientific Popularization 2009, pronounced the lecture entitled “Climate change on a live Earth” for the award ceremony, on 6 October 2009 in Santiago de Compostela. The Consortium of Santiago and the University of Santia­go de Compostela, aware of the importance of the trans­fer of knowledge and society’s science education needs, agreed in 2006 to create the ConCiencia Programme to invite the greatest intellects of the international scientific community to transmit their ideas in a city which is a sym­bol of culture and knowledge. Under the auspices of the ConCiencia Programme, the Fonseca Prize for Scientific Popularization was created with the aim of promoting the transfer of knowledge to the society. The award recogniz­es those individuals who have had a distinguished career in the field of scientific communication or are a public ref­erence in stimulating and promoting the general interest in scientific and technical knowledge. Other recipients of this award have been Professor Stephen W. Hawking (2008), Sir David Attenborough (2010) and Sir Roger Penrose (2011). More information: www.usc.es/conciencia.001-092 Contributions 7-1.indd   20 11/11/2011   14:04:28

Climate change on a live Earth

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