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[escepticos] The Skeptical Environmentalist (fwd)

Reenvio esto que parece que no llego. Por los archivos adjuntos,
imagino, asi que no los pongo.

---------- Forwarded message ----------
Date: Tue, 5 Feb 2002 15:06:39 +0100 (CET)
From: Carlos Ungil <ungil en mail.cern.ch>
To: escepticos en ccdis.dis.ulpgc.es, esceptica en yahoogroups.com
Subject: The Skeptical Environmentalist

Hola, hola.

Hace unos meses mande a la(s) lista(s) un articulo de The Economist,
avance de un libro, en el que se afirmaba que los ecologistas son unos
exagerados. Esta semana vuelven a dedicarle un artículo y un
editorial. La verdad es que no he visto el numero de enero de 
Scientific American que mencionan, ni he leido el libro. Mi unico 
conocimiento del tema se reduce a lo que aqui corto y pego. No tengo 
ningun interes en defender las posturas que aqui se expresan, 
simplemente mando esto por si a alguien le interesa.

Pueden encontrarse algunas de las criticas y las replicas del gachó en
http://www.lomborg.com, pero todavia no he tenido tiempo de leerlo.



[ Aug 2nd 2001 ]

The truth about the environment

Environmentalists tend to believe that, ecologically speaking, things
are getting worse and worse. Bjorn Lomborg, once deep green himself,
argues that they are wrong in almost every particular

Ecology and economics should push in the same direction. After all,
the "eco" part of each word derives from the Greek word for "home",
and the protagonists of both claim to have humanity's welfare as their
goal. Yet environmentalists and economists are often at
loggerheads. For economists, the world seems to be getting better. For
many environmentalists, it seems to be getting worse.

These environmentalists, led by such veterans as Paul Ehrlich of
Stanford University, and Lester Brown of the Worldwatch Institute,
have developed a sort of "litany" of four big environmental fears:

* Natural resources are running out. 

* The population is ever growing, leaving less and less to eat. 

* Species are becoming extinct in vast numbers: forests are
disappearing and fish stocks are collapsing.

* The planet's air and water are becoming ever more polluted.

Human activity is thus defiling the earth, and humanity may end up
killing itself in the process.

The trouble is, the evidence does not back up this litany. First,
energy and other natural resources have become more abundant, not less
so since the Club of Rome published "The Limits to Growth" in
1972. Second, more food is now produced per head of the world's
population than at any time in history. Fewer people are
starving. Third, although species are indeed becoming extinct, only
about 0.7% of them are expected to disappear in the next 50 years, not
25-50%, as has so often been predicted. And finally, most forms of
environmental pollution either appear to have been exaggerated, or are
transient--associated with the early phases of industrialisation and
therefore best cured not by restricting economic growth, but by
accelerating it. One form of pollution--the release of greenhouse gases
that causes global warming--does appear to be a long-term phenomenon,
but its total impact is unlikely to pose a devastating problem for the
future of humanity. A bigger problem may well turn out to be an
inappropriate response to it.

Can things only get better?

Take these four points one by one. First, the exhaustion of natural
resources. The early environmental movement worried that the mineral
resources on which modern industry depends would run out. Clearly,
there must be some limit to the amount of fossil fuels and metal ores
that can be extracted from the earth: the planet, after all, has a
finite mass. But that limit is far greater than many environmentalists
would have people believe.

Reserves of natural resources have to be located, a process that costs
money. That, not natural scarcity, is the main limit on their
availability. However, known reserves of all fossil fuels, and of most
commercially important metals, are now larger than they were when "The
Limits to Growth" was published. In the case of oil, for example,
reserves that could be extracted at reasonably competitive prices
would keep the world economy running for about 150 years at present
consumption rates. Add to that the fact that the price of solar energy
has fallen by half in every decade for the past 30 years, and appears
likely to continue to do so into the future, and energy shortages do
not look like a serious threat either to the economy or to the

The development for non-fuel resources has been similar. Cement,
aluminium, iron, copper, gold, nitrogen and zinc account for more than
75% of global expenditure on raw materials. Despite an increase in
consumption of these materials of between two- and ten-fold over the
past 50 years, the number of years of available reserves has actually
grown. Moreover, the increasing abundance is reflected in an
ever-decreasing price: The Economist's index of prices of industrial
raw materials has dropped some 80% in inflation-adjusted terms since

Next, the population explosion is also turning out to be a bugaboo. In
1968, Dr Ehrlich predicted in his best selling book, "The Population
Bomb", that "the battle to feed humanity is over. In the course of the
1970s the world will experience starvation of tragic
proportions--hundreds of millions of people will starve to death."

That did not happen. Instead, according to the United Nations,
agricultural production in the developing world has increased by 52%
per person since 1961. The daily food intake in poor countries has
increased from 1,932 calories, barely enough for survival, in 1961 to
2,650 calories in 1998, and is expected to rise to 3,020 by
2030. Likewise, the proportion of people in developing countries who
are starving has dropped from 45% in 1949 to 18% today, and is
expected to decline even further to 12% in 2010 and just 6% in
2030. Food, in other words, is becoming not scarcer but ever more
abundant. This is reflected in its price. Since 1800 food prices have
decreased by more than 90%, and in 2000, according to the World Bank,
prices were lower than ever before.

Modern Malthus
Dr Ehrlich's prediction echoed that made 170 years earlier by Thomas
Malthus. Malthus claimed that, if unchecked, human population would
expand exponentially, while food production could increase only
linearly, by bringing new land into cultivation. He was
wrong. Population growth has turned out to have an internal check: as
people grow richer and healthier, they have smaller families. Indeed,
the growth rate of the human population reached its peak, of more than
2% a year, in the early 1960s. The rate of increase has been declining
ever since. It is now 1.26%, and is expected to fall to 0.46% in
2050. The United Nations estimates that most of the world's population
growth will be over by 2100, with the population stabilising at just
below 11 billion (see chart 1).

Malthus also failed to take account of developments in agricultural
technology. These have squeezed more and more food out of each hectare
of land. It is this application of human ingenuity that has boosted
food production, not merely in line with, but ahead of, population
growth. It has also, incidentally, reduced the need to take new land
into cultivation, thus reducing the pressure on biodiversity.

Third, that threat of biodiversity loss is real, but exaggerated. Most
early estimates used simple island models that linked a loss in
habitat with a loss of biodiversity. A rule-of-thumb indicated that
loss of 90% of forest meant a 50% loss of species. As rainforests
seemed to be cut at alarming rates, estimates of annual species loss
of 20,000-100,000 abounded. Many people expected the number of species
to fall by half globally within a generation or two.

However, the data simply does not bear out these predictions. In the
eastern United States, forests were reduced over two centuries to
fragments totalling just 1-2% of their original area, yet this
resulted in the extinction of only one forest bird. In Puerto Rico,
the primary forest area has been reduced over the past 400 years by
99%, yet "only" seven of 60 species of bird has become extinct. All
but 12% of the Brazilian Atlantic rainforest was cleared in the 19th
century, leaving only scattered fragments. According to the
rule-of-thumb, half of all its species should have become
extinct. Yet, when the World Conservation Union and the Brazilian
Society of Zoology analysed all 291 known Atlantic forest animals,
none could be declared extinct. Species, therefore, seem more
resilient than expected. And tropical forests are not lost at annual
rates of 2-4%, as many environmentalists have claimed: the latest UN
figures indicate a loss of less than 0.5%.
Fourth, pollution is also exaggerated. Many analyses show that air
pollution diminishes when a society becomes rich enough to be able to
afford to be concerned about the environment. For London, the city for
which the best data are available, air pollution peaked around 1890
(see chart 2). Today, the air is cleaner than it has been since
1585. There is good reason to believe that this general picture holds
true for all developed countries. And, although air pollution is
increasing in many developing countries, they are merely replicating
the development of the industrialised countries. When they grow
sufficiently rich they, too, will start to reduce their air pollution.

All this contradicts the litany. Yet opinion polls suggest that many
people, in the rich world, at least, nurture the belief that
environmental standards are declining. Four factors cause this
disjunction between perception and reality.

Always look on the dark side of life 

One is the lopsidedness built into scientific research. Scientific
funding goes mainly to areas with many problems. That may be wise
policy, but it will also create an impression that many more potential
problems exist than is the case.

Secondly, environmental groups need to be noticed by the mass
media. They also need to keep the money rolling in. Understandably,
perhaps, they sometimes exaggerate. In 1997, for example, the
Worldwide Fund for Nature issued a press release entitled, "Two-thirds
of the world's forests lost forever". The truth turns out to be nearer

Though these groups are run overwhelmingly by selfless folk, they
nevertheless share many of the characteristics of other lobby
groups. That would matter less if people applied the same degree of
scepticism to environmental lobbying as they do to lobby groups in
other fields. A trade organisation arguing for, say, weaker pollution
controls is instantly seen as self-interested. Yet a green
organisation opposing such a weakening is seen as altruistic, even if
a dispassionate view of the controls in question might suggest they
are doing more harm than good.

A third source of confusion is the attitude of the media. People are
clearly more curious about bad news than good. Newspapers and
broadcasters are there to provide what the public wants. That,
however, can lead to significant distortions of perception. An example
was America's encounter with El Niño in 1997 and 1998. This climatic
phenomenon was accused of wrecking tourism, causing allergies, melting
the ski-slopes and causing 22 deaths by dumping snow in Ohio.

A more balanced view comes from a recent article in the Bulletin of
the American Meteorological Society. This tries to count up both the
problems and the benefits of the 1997-98 Niño. The damage it did was
estimated at $4 billion. However, the benefits amounted to some $19
billion. These came from higher winter temperatures (which saved an
estimated 850 lives, reduced heating costs and diminished spring
floods caused by meltwaters), and from the well-documented connection
between past Niños and fewer Atlantic hurricanes. In 1998, America
experienced no big Atlantic hurricanes and thus avoided huge
losses. These benefits were not reported as widely as the losses.

The fourth factor is poor individual perception. People worry that the
endless rise in the amount of stuff everyone throws away will cause
the world to run out of places to dispose of waste. Yet, even if
America's trash output continues to rise as it has done in the past,
and even if the American population doubles by 2100, all the rubbish
America produces through the entire 21st century will still take up
only the area of a square, each of whose sides measures 28km (18
miles). That is just one-12,000th of the area of the entire United

Ignorance matters only when it leads to faulty judgments. But fear of
largely imaginary environmental problems can divert political energy
from dealing with real ones. The table above, showing the cost in the
United States of various measures to save a year of a person's life,
illustrates the danger. Some environmental policies, such as reducing
lead in petrol and sulphur-dioxide emissions from fuel oil, are very
cost-effective. But many of these are already in place. Most
environmental measures are less cost-effective than interventions
aimed at improving safety (such as installing air-bags in cars) and
those involving medical screening and vaccination. Some are absurdly

Yet a false perception of risk may be about to lead to errors more
expensive even than controlling the emission of benzene at tyre
plants. Carbon-dioxide emissions are causing the planet to warm. The
best estimates are that the temperature will rise by some 2°-3°C in
this century, causing considerable problems, almost exclusively in the
developing world, at a total cost of $5,000 billion. Getting rid of
global warming would thus seem to be a good idea. The question is
whether the cure will actually be more costly than the ailment.

Despite the intuition that something drastic needs to be done about
such a costly problem, economic analyses clearly show that it will be
far more expensive to cut carbon-dioxide emissions radically than to
pay the costs of adaptation to the increased temperatures. The effect
of the Kyoto Protocol on the climate would be minuscule, even if it
were implemented in full. A model by Tom Wigley, one of the main
authors of the reports of the UN Climate Change Panel, shows how an
expected temperature increase of 2.1°C in 2100 would be diminished by
the treaty to an increase of 1.9°C instead. Or, to put it another way,
the temperature increase that the planet would have experienced in
2094 would be postponed to 2100.

So the Kyoto agreement does not prevent global warming, but merely
buys the world six years. Yet, the cost of Kyoto, for the United
States alone, will be higher than the cost of solving the world's
single most pressing health problem: providing universal access to
clean drinking water and sanitation. Such measures would avoid 2m
deaths every year, and prevent half a billion people from becoming
seriously ill.

And that is the best case. If the treaty were implemented
inefficiently, the cost of Kyoto could approach $1 trillion, or more
than five times the cost of worldwide water and sanitation
coverage. For comparison, the total global-aid budget today is about
$50 billion a year.

To replace the litany with facts is crucial if people want to make the
best possible decisions for the future. Of course, rational
environmental management and environmental investment are good
ideas--but the costs and benefits of such investments should be
compared to those of similar investments in all the other important
areas of human endeavour. It may be costly to be overly optimistic--but
more costly still to be too pessimistic.


Bjorn Lomborg is a statistician at the University of Aarhus, Denmark,
who once held what he calls "left-wing Greenpeace views". In 1997, he
set out to challenge Julian Simon, an economist who doubted
environmentalist claims--and found that the data generally supported
Simon. His book, "The Skeptical Environmentalist", will be published
in English by Cambridge University Press in a month's time.


[ Sep 6th 2001 ]

Doomsday postponed

The Skeptical Environmentalist: Measuring the Real State of the World
By Bjorn Lomborg

Cambridge University Press; 540 pages; 
$69.95 ($27.95 paperback) and £47.50 ($17.95 paperback)
This is one of the most valuable books on public policy--not merely on
environmental policy--to have been written for the intelligent general
reader in the past ten years. Its target is environmental pessimism,
the defining mood of the age. By the end, fair-minded readers will
find that most of the concerns they had about the future of the planet
have given way to fury at the army of dissembling environmentalists
who have dedicated themselves to stirring up panic by concealing the

The idea that the world is heading for ruin seems to be taken for
granted by almost every television news programme and newspaper,
whether the subject is poverty in Africa, global warming, trends in
population, traffic jams in Manchester or a spell of bad weather in
Detroit. This gloom directly affects the debate on environmental
policy, of course, but its influence goes wider than that. It supports
the conviction that capitalism is self-destructive, and so lurks in
the background of many an economic debate, broad or narrow. Yet this
faith in looming environmental disaster, Mr Lomborg shows, is false.

The author is a professor of statistics at the University of
Aarhus. His expertise lies in numbers and sources. So in "The
Skeptical Environmentalist" he examines the views of the world's
leading environmental pressure groups simply by consulting the sources
(if any) they cite, together with other relevant literature. Again and
again, he finds that the pessimists' claims are falsified not merely
by the available scientific evidence but by their own quoted sources.

The accumulating power of the book lies in the sheer toll of carefully
documented examples. Bearing that in mind, consider just one, to get a
flavour. The Worldwatch Institute has claimed that the world's forests
have "declined significantly" in recent decades. In fact, the longest
data series, gathered by a United Nations agency, shows that global
forest cover grew between 1950 and 1994. In particular, the institute
noted, Canada is losing 200,000 hectares of forest a year. On checking
the quoted source, Mr Lomborg finds that Canada's forests grew by
174,000 hectares a year. This is representative: the book exposes
countless errors, evasions and distortions of this sort.

As well as insisting on statistical probity, Mr Lomborg brings another
intellectual virtue to the task: an interest in feasible
alternatives. On global warming, for instance, he shows that standard
claims about the extent of the problem are deliberately exaggerated
(though he does not deny that some global warming is going on); beyond
that, however, he asks about costs. The cost of preventing warming
could easily outweigh the harm caused by letting it happen, and by a
very wide margin, depending on the method. If concern for developing
countries came first (and that is where global warming will cause most
harm), there would be much better ways of spending money than on
schemes such as the Kyoto plan. Providing universal access to clean
water would do more good than the tiny cut in warming envisaged by
Kyoto, at about a fifth of the price.

Mr Lomborg is not the first to take a stand of this sort against the
excesses of the environmentalist movement. He follows in the footsteps
of the late Julian Simon, one of the 20th century's unsung heroes of
economics. (Mr Lomborg generously acknowledges Simon's role.) But
Simon was a quirky conservative, and therefore ignored by the
mainstream media. Mr Lomborg is a soft-left Greenpeace defector, a
photogenic blond Dane, a charming self-promoter who understands the
importance of, as he puts it, "being seen to be nice". That makes him
a story. His findings have caused a furore in Scandinavia and, with
this book, show signs of being noticed elsewhere. Good. More power to
him. "The Skeptical Environmentalist" is a triumph.


[ Feb 2nd 2002 ]

Defending science

The fury inspired by a new book is extraordinary, and raises some
Bjorn Lomborg, a Danish statistician, no doubt hoped to spark
controversy with his book, "The Skeptical Environmentalist"--an attack
on "the litany", as he calls it, of bogus doom and gloom about the
state of the planet. He has not been ignored, which is probably an
author's worst fate, but he may be wishing he had been. The response
to the book in many quarters has been apoplectic. Mr Lomborg is being
called a liar, a fraud and worse. People are refusing to share a
platform with him. He turns up in Oxford to talk about his book, and
the author (it is claimed) of a forthcoming study on climate change
throws a pie in his face.

The Economist is not a neutral in all this. Before Mr Lomborg
published "The Skeptical Environmentalist", we ran a signed essay by
him which gave a summary. Later we reviewed his book in glowing
terms. What has inspired the subsequent fury? Mr Lomborg argues that
the environment is not in nearly such bad shape as green activists and
their dupes in the media would have the public believe; that
technology is improving lives across most of the planet; that western
civilisation is environmentally sustainable; and that the Kyoto
agreement on carbon emissions is bad policy as it stands.

How dare he say that?

Mr Lomborg defends these positions on the basis of official data and
published science. Environmentalists typically use the same sources,
but, as Mr Lomborg lays bare, are much less scrupulous about setting
short runs of data in their long-term context, for instance, or about
quoting ranges of data, where that is appropriate, rather than
whatever extreme of any given range best suits their case. Mr Lomborg
diligently piles on the footnotes (2,930 of them) so there is no
dispute about where his numbers have come from. His claims, of course,
could still be true or false. They are largely true, in our
opinion. But what is strangest in all this fuss is the idea that
simply by making them he has put himself far beyond the pale of
respectable discourse, as so many of his critics appear to believe.

Mr Lomborg, it is important to note, does not say that all is well
with the world. And The Economist for that matter does not say that Mr
Lomborg is right about every issue he addresses. Environmental policy
involves uncertainty, as Mr Lomborg emphasises; now and then this
raises doubts that deserve more attention than he gives them (see
article). We do believe, however, that he is right on his main points,
that his critique of much green activism and its reporting in the
media is just, and, above all, that where there is room for
disagreement, Mr Lomborg invites and facilitates discussion, rather
than seeking to silence it. The same cannot be said for many of his

The January issue of Scientific American devoted many pages to a
series of articles trashing "The Skeptical Environmentalist". The
authors, all supporters of the green movement, were strong on contempt
and sneering, but weak on substance. The arresting thing about
Scientific American's coverage, however, was not this barrage of
ineffective rejoinders but the editor's notion of what was going on:
"Science defends itself against the Skeptical Environmentalist," he

That is amazing. Mr Lomborg's targets are green scare-mongers and
their credulous servants in the media. He uses the findings of
scientists to press his case. How can using science to criticise the
Kyoto agreement, to show that the world's forests are not
disappearing, to demonstrate that the planet's supplies of energy and
food will suffice indefinitely, and the rest, constitute an attack on
science? If that is so, the scholars whose work supports those
positions are presumably attacking science too, and had better stand
in line for a pie in the face.

More is at stake here than a row about a book or the judgment of a
magazine editor. Many of Mr Lomborg's critics are respected
scientists. Some seem to think that Mr Lomborg's lack of training in
their fields disqualifies him from debating environmental
policy. E.O. Wilson, one of the world's most distinguished scientists,
and a dedicated green, deplores "the Lomborg scam" because of "the
extraordinary amount of scientific talent that has to be expended to
combat [him] in the media...[Mr Lomborg and his kind] are the parasite
load on scholars who earn success through the slow process of peer
review and approval." That would be wrong even if all scientists
shared Mr Wilson's fear that the world will become a "hellish place to
exist", which they do not. Environmental policy involves politics and
economics, compromises and trade-offs, a division of burdens
geographically and over time. It could not be left to scientists, even
if they agreed on the science. We parasites would even then be right
to insist on having our say.

Leeches of the world, unite

Mr Wilson's insufferable arrogance is bad enough, but there's
worse. The fuss over Mr Lomborg highlights an attitude among some
media-conscious scientists that militates not just against good policy
but against the truth. Stephen Schneider, one of Scientific American's
anti-Lomborgians, spoke we suspect not just for himself when he told
Discover in 1989: "[We] are not just scientists but human beings as
well. And like most people we'd like to see the world a better
place...To do that we need to get some broad-based support, to capture
the public's imagination. That, of course, entails getting loads of
media coverage. So we have to offer up scary scenarios, make
simplified, dramatic statements, and make little mention of any doubts
we might have...Each of us has to decide what the right balance is
between being effective and being honest." In other words, save
science for other scientists, in peer-reviewed journals and other
sanctified places. In public, strike a balance between telling the
truth and telling necessary lies.

Science needs no defending from Mr Lomborg. It may very well need
defending from champions like Mr Schneider.


[ Feb 2nd 2002 ]

The litany and the heretic

Why has Bjorn Lomborg created such a stir among environmentalists?
"I'm afraid there isn't much scientific controversy about Mr
Lomborg. He occupies a very junior position in Denmark (an 'associate
professor' does not exactly mean the same thing that it does in the
United States), he has one possibly very flawed paper in an
international journal on game theory, no publications on environmental
issues, and yet manages to dismiss the science of dozens of the
world's best scientists, including Nobel laureates, Japan and Crawford
prize-winners and the like. As any sensible person would expect, his
facts are usually fallacies and his analysis is largely non-existent."

Those contemptuous words from Stuart Pimm, a professor of conservation
biology at Columbia University, are fairly representative of the
response from many environmental scientists and activists to Bjorn
Lomborg's recent book, "The Skeptical Environmentalist". In the weeks
since the book's release, virtually every large environmental group
has weighed in with a denunciation. Numerous heavyweights of science
have penned damning articles and reviews in leading journals. Dr Pimm,
for one, railed against Dr Lomborg in Nature, while Scientific
American recently devoted 11 pages to attacks from scientists known
for their environmental activism.

Dr Lomborg's critics protest too much. They are rattled not because,
as they endlessly insist, Dr Lomborg lacks credentials as an
environmental scientist and is of no account, but because his book is
such a powerful and persuasive assault on the central tenets of the
modern environmental movement.

Just the facts

Curious about the true state of the planet, the author--who makes no
claims to expertise in environmental science, only to statistical
expertise--has scrutinised reams of official data on everything from
air pollution to energy availability to climate change. As an
instinctive green and a former member of Greenpeace, he was surprised
to find that the world's environment is not, in fact, getting ever
worse. Rather, he shows, most environmental indicators are stable or

One by one, he goes through the "litany", as he calls it, of four big
environmental fears:

* Natural resources are running out.

* The population is ever growing, leaving less and less to eat.

* Species are becoming rapidly extinct, forests are vanishing and fish stocks are collapsing.

* Air and water are becoming ever more polluted.

In each case, he demonstrated that the doom and gloom is wildly
exaggerated. Known reserves of fossil fuels and most metals have
risen. Agricultural production per head has risen; the numbers facing
starvation have declined. The threat of biodiversity loss is real but
exaggerated, as is the problem of tropical deforestation. And
pollution diminishes as countries grow richer and tackle it

In other words, the planet is not in peril. There are problems, and
they deserve attention, but nothing remotely so dire as most of the
green movement keeps saying.

Nor is that all he shows. The book exposes--through hundreds of
detailed, meticulously footnoted examples--a pattern of exaggeration
and statistical manipulation, used by green groups to advance their
pet causes, and obligingly echoed through the media. Bizarrely, one of
Dr Lomborg's critics in Scientific American criticises as an
affectation the book's insistence on documenting every statistic and
every quotation with a reference to a published source. But the
complaint is not so bizarre when one works through the references,
because they so frequently expose careless reporting and
environmentalists' abuse of scientific research.

The replies to Dr Lomborg in Scientific American and elsewhere score
remarkably few points of substance*. His large factual claims about
the current state of the world do not appear to be under
challenge--which is unsurprising since they draw on official data. What
is under challenge, chiefly, is his outrageous presumption in starting
a much-needed debate.

Some argue that scientists who favour stronger policies to improve the
environment must use the same tactics as any other political
lobby--from steel companies fighting for tariffs on imports to farmers
demanding more subsidies. The aim, after all, is to win public favour
and government support. Whether such a view is consistent with the
obligation science owes to the truth is debatable, at best. If
scientists want their views to be accorded the respect due to science,
then they must speak as scientists, not as lobbyists.

Dr Lomborg's work has its flaws. He has made some errors in his
statistical analysis, as he acknowledges on his website. And there are
broader issues, especially to do with the aggregation of data and the
handling of uncertainty, where his book is open to challenge. For
instance, his approach of examining data at a global level, while
statistically sound, tends to mask local environmental trends. Global
marine productivity has indeed risen, as he says--but this disguises
collapses in particular species in particular places. Dr Lomborg
argues that such losses, seen in a long-term perspective, do not
matter much. Many would disagree, not least the fishermen in the areas

Allen Hammond of the World Resources Institute (WRI) makes a related
point. He accepts Dr Lomborg's optimistic assessment of the
environment, but says it holds only for the developed world. The
aggregate figures offered in the book mask worsening pollution in the
mega-cities of the poor world. Dr Lomborg agrees that there are local
and regional environmental pressures, and that these matter a lot, but
it is fair to point out that the book has little to say about them,
except to argue that rising incomes will help.

The book gives little credit to environmental policy as a cause of
environmental improvement. That is a defensible position, in fact, but
the book does not trouble to make the case. And another important
question is somewhat skated over: the possibility that some
environmental processes involve irreversible "triggers", which, once
pulled, lead to sudden and disastrous deterioration. Climate
scientists believe, and Dr Lomborg does not deny, that too much
warming could lead to irreversible bad outcomes such as the collapse
of the mid-Atlantic "conveyor belt" (an ocean current that warms
Europe). The science here is thin: nobody knows what level of
greenhouse gases in the atmosphere would trigger such a calamity. But
the risk argues for caution.

Dr Lomborg's assessment of the science in this area leads him to
venture that warming is more likely to be at the low end of the range
expected by leading experts than at the high end. He argues that the
most-cited climate models misjudge factors such as the effects of
clouds, aerosols and the solar cycle. That is plausible, and there is
science to support it, but the conclusion is far from certain. Again,
it is reasonable to argue that such uncertainty makes it better to err
on the side of caution.

Sensible people will disagree about the course that policy should
take. Dr Lomborg--a courteous fellow--seems willing to talk calmly to
his opponents. For the most part, while claiming in some cases to be
men of science, his opponents do not return the compliment.

Homo ecologicus

Despite its limitations, "The Skeptical Environmentalist" delivers a
salutary warning to conventional thinking. Dr Lomborg reminds militant
greens, and the media that hang on their every exaggerated word about
environmental calamity, that environmental policy should be judged
against the same criteria as other kinds of policy. Is there a
problem? How bad is it? What will it cost to fix? Is that the best way
to spend those resources?

This is exactly what Tom Burke, a leading British environmentalist,
denied in a debate he had with Dr Lomborg in Prospect, a British
magazine. "What I find most egregious [in] your climate-change
argument, however, is the proposition that the world faces a choice
between spending money on mitigating climate change, and providing
access to clean drinking water and sanitation in the developing
world. We must and can do both. Such artificial choices may be
possible in an academic ivory tower where ideas can be arranged to
suit the prejudices of the occupant, but they are not available in the
real world and it is dishonest to suggest that they are."

On the contrary, Mr Burke. Only in an ivory tower could choices such
as these be called "artificial". Democratic politics is about nothing
but choices of that sort. Green politics needs to learn that resources
are not unlimited.