Deep Thought: Climate of Superstition |
by Lord Nigel Lawson
|
original article: The
Spectator 11th March 2006
(needs free registration to read)
There is no opinion, however absurd, which men will not
readily embrace
as soon as they can be brought to the conviction that
it is generally adopted.
--Schopenhauer
Next week marks the deadline that has been set for reactions to the less than
satisfactory discussion paper that has emerged from the government's belated review of the
important issue of the economics of climate change. It is important for David Cameron, too. For, while rightly giving the
environment a high priority, he is in danger, over this issue, of making commitments which, in government, he
would find it extremely damaging to honour.
Crucial though the economics of climate change is, the starting point clearly
has to be the science. I readily admit that I am not a scientist myself; but then the vast
majority of those who pronounce with far greater certainty than I shall on this aspect of the
issue are not scientists either; and the vast majority of those scientists who speak with
great certainty and apparent authority about climate change are not in fact climate scientists
at all.
We know for certain only two things. The first is a matter of history rather
more than science: namely, that since about 1860, when accurate temperature records were first
collected on a comprehensive basis, northern hemisphere temperatures have risen by about 0.6oC;
and that this coincides with a steady growth in the amount of carbon dioxide in the
atmosphere, a significant part of which is a consequence of industrial and other man-made
emissions.
The second is that our planet is kept from being too cold for life as we know it
to survive by the so-called greenhouse effect, which traps some of the heat from the sun's
rays. This is overwhelmingly - somewhere between 75 and 95 per cent - caused by clouds and
other forms of water vapour; and the carbon dioxide in the atmosphere accounts for most of the
remainder. But so great is the uncertainty of climate science that it is impossible to say -
and it is hotly disputed - how much of the modest warming that has been experienced since 1860
is due to the man-made increase in carbon dioxide.
The United Nations intergovernmental panel on climate change (usually known as
the IPCC) has produced immensely complex computerised models which generate a specific
temperature rise for any projected increase in carbon dioxide emissions; but
of course the outcomes simply reflect the assumptions implicit in the models, and it is these assumptions that are
inevitably highly
speculative. The IPCC models assume that the recorded warming during
the 20th century was entirely caused by man-made emissions of greenhouse gases, of which carbon
dioxide is clearly
the most important.
This may be true; but equally it may not be. There are, for example, climate
scientists who believe that the principal cause has been land-use changes, in particular
urbanisation (the so-called urban heat island effect) and to some extent forest clearance for
farming. But much more important is the fact that the Earth's climate has always been subject to
natural variation, nothing to do with man's activities. Again, climate scientists differ
about the causes of this, although most agree that variations in solar radiation play a
key part.
It is well established, for example, that a thousand years ago, well before
industrialisation, there was what has become known as the mediaeval warm period, when temperatures
were probably
almost as high as, if not higher than, they are today. Going back even further,
during the Roman empire, it was even warmer - so much so that the Romans were able to
produce drinkable wine in the north of England. More recently, during the 17th and early 18th
centuries, there was what has become known as the little ice age, when the Thames was regularly
frozen over in winter, and substantial ice fairs held on the frozen river became a popular
attraction.
Even during the period since 1860, for which we have accurate temperature
records, the picture is complicated. While the amount of man-made carbon dioxide in the atmosphere
has, since the
industrial revolution, steadily increased, the corresponding temperature record
is more cyclical, displaying four distinct phases.
Between 1860 and 1915 there was virtually no change in northern hemisphere
temperatures. Between 1915 and 1945 there was a rise of about 0.4oC. Between 1945 and 1965 the
temperature
fell by about 0.2oC - and alarmist articles by Professor James Lovelock and
others began to appear, warning about the prospect of a new ice age. Finally, between 1965 and
2000 there was a further increase of about 0.4oC, thus arriving at the overall increase of
0.6oC over the 20th century as a whole. Although, so far this century, there has been nothing
to match the high temperature recorded in 1998, it would be rash to assume that this latest
upward phase has ended.
At first sight, this might suggest a considerable natural variability, and thus
inherent unpredictability. The official IPCC story, however, which is incorporated into
its model, is that, before 1965, power stations (largely coal-fired) emitted large amounts of
sulphur, producing sulphur dioxide in the atmosphere, which had a cooling effect - by
dimming the sun's rays - that more than offset the warming effect of the carbon dioxide. Since
1965, it is claimed, when the industrialised West took steps to prevent this pollution, the
carbon dioxide effect has reigned supreme.
Again, this may be so - or it may not be. Certainly, it
makes it even harder to explain as man-made the 0.4oC increase in temperature between 1915 and 1945, when power
station emissions were as dirty as they have ever been. So much for the science.
But the IPCC's scenarios - which incidentally it insists are not forecasts,
although it must be well aware that that is how they were bound to be interpreted - showing a
rise in global temperatures of between 1oC and 6oC by the end of this century, derive not only
from the speculative assumption that the increase which has already occurred is entirely
due to the rise in man-made carbon dioxide emissions. They also depend crucially on the
IPCC's assumptions about how much these emissions will, on a business-as-usual basis, rise further
between now and the end of this century. And this is a matter of economics rather than
science.
Two economic assumptions are of particular importance. These are, first, the
rate of world economic growth between now and the end of this century; and, second, the energy
intensity of that growth.
The IPCC's various scenarios assume a rate of world
economic growth over the whole of this century of between 2.2 per cent and 3 per cent a year. History would
suggest that, while
perfectly possible, this is somewhat on the optimistic side. Even more
optimistic is the way in which these overall world growth rates are assumed to be composed.
Essentially, they are derived from assuming a very high rate of growth in the developing world as a
whole over the next 100 years, with the result that living standards in terms of GDP per
head steadily converge with those of the developed world by the year 2100.
In other words, living standards throughout the developing world, in all the
IPCC scenarios, are projected to be, by 2100, substantially higher than they are in Europe and
the United States today. This may happen - indeed I hope it will, and it should certainly
cheer up those who might otherwise be depressed by the climate alarmists - but it is clear that
the IPCC's scenarios fail to capture the realistic range of possibilities.
As to the IPCC's projections of the rate of growth of carbon dioxide emissions
which these rates of economic growth may be expected to generate, the position is even more
perplexing. Over the past 30 years the annual growth in world carbon dioxide emissions has
been roughly half the rate of growth of the economy as a whole, and within those 30 years the
energy intensity of growth has been steadily declining.
This is hardly surprising. In the first place, economic
progress is a story of increasing efficiency in the use of all factors of production. In the case of
labour, this is customarily referred to as growth in productivity; but precisely the same applies to energy.
Secondly, the pattern of world economic growth has been changing, with services, which are
less energy-intensive, growing faster than manufacturing, which is more so.
What is surprising, however, is that every one of the IPCC's scenarios for the
21st century assume, without offering any evidence, that this trend will now be abruptly
reversed, and that as a result the growth in carbon emissions per unit of output will be
significantly greater than in the recent past. It is clear, to say the least, that the IPCC scenarios
do not capture the true range of plausible futures.
Thus there is a pronounced upward bias in its emissions
scenarios, which of course feeds directly into a pronounced upward bias in projected climate change.
And that is assuming,
as the IPCC does, that the whole of the 0.6oC warming that occurred during the
20th century was attributable to man-made emissions - which, as we have seen, is itself
distinctly uncertain.
Does all this mean that we can forget about the threat of climate change
altogether? I do not believe that would be wise, not least because natural climate variations are
likely to continue to occur, irrespective of human actions. But what it does mean is that
we need to stand back and think more rationally about the most cost-effective form of
insurance policy to take out against a supposed man-made threat which is both less certain and
less urgent than is commonly supposed, but which, together with natural variation, cannot
altogether be dismissed as a threat.
It is clear that the present approach, under which the industrialised countries
of the world agree to somewhat arbitrarily assigned fixed limits to their carbon dioxide
emissions by a specified date - the so-called Kyoto system - is the most expensive and least
rational insurance policy, and that the sooner it is abandoned the better.
Even its strongest advocates admit that, even if fully
implemented (which it is now clear it will not be), the existing Kyoto agreement, which came into force last year and
expires in
2012, would do virtually nothing to reduce future rates of global warming.
Its importance, in its advocates' eyes, is as the first step towards further such agreements of
a considerably more restrictive nature. But this is wholly unrealistic, and fundamentally
flawed for a number of reasons. In the first place, the United States, the largest source of carbon
dioxide emissions, has refused to ratify the treaty and has made clear its intention of
having no part in any similar future agreements. And if anyone should imagine that this is
simply an eccentricity of the present Bush administration, it is worth recalling that,
during the Clinton presidency, the US Senate voted by an eloquent majority of 95 to 0
against ratifying Kyoto.
In the second place, the developing countries - including such major
contributors to future carbon dioxide emissions as China, India and Brazil - are effectively outside
the process and determined to remain so. It is this that has led to the creation of the
so-called 'Asia-Pacific partnership on clean development and climate', a counter-Kyoto grouping of the
United States, China, India, Australia, Japan and South Korea, which held its inaugural meeting
earlier this year.
The developing countries' argument is a simple one. They contend that the
industrialised countries of the Western world achieved their prosperity on the basis of cheap
carbon-based energy; and that it is now the turn of the poor developing countries to emulate
them. And they add that if there is a problem now of excessive carbon dioxide concentrations in
the Earth's atmosphere, it is the responsibility of those who caused it to remedy it.
Be that as it may, the consequences are immense. China alone last year embarked
on a programme of building 562 large coal-fired power stations by 2012 - that is, a new
coal-fired power station every five days for seven years. Since coal-fired power stations emit
roughly twice as much carbon dioxide per gigawatt of electricity as gas-fired ones, it is not
surprising that it is generally accepted that within the next 20
years China will overtake the United States as the largest source of emissions. India, which like China has
substantial indigenous coal reserves, is set to follow a similar path, as is Brazil.
Then there is the cost of the Kyoto approach to consider. The logic of Kyoto is
to make emissions permits sufficiently scarce to raise their price to the point where carbon-based
energy is so expensive
that carbon-free energy sources, and other carbon-saving measures, become fully
economic. This clearly involves a very much greater rise in energy prices than anything we have
yet seen. There must
be considerable doubt whether this is politically sustainable - particularly
when the economic cost, in terms of slower economic growth, would be substantial.
In reality, if the Kyoto approach were to be pursued beyond 2012, which is -
fortunately - most unlikely, the price increase would in practice be mitigated in the global
economy in which we now live. For as energy prices in Europe started to rise, with the prospect of
further rises to come, energy-intensive industries and processes would
progressively close down in Europe and relocate in countries like China, where relatively cheap energy was still
available.
No doubt Europe could, at some cost, adjust to this, as it has to the migration
of most of its textile industry to China and elsewhere. But it is difficult to see the point of
it. For if carbon dioxide emissions in Europe are reduced only for them to be further
increased in China, there is no net reduction in global emissions at all. Indeed, given the nature
of Chinese power generation, there might well be an increase.
So, if not Kyoto, what is the most sensible approach?
Far and away the most cost-effective policy for the
world to adopt is to identify the most harmful consequences that may flow from global warming and, if they start to
occur, to take
action to counter them. There are three reasons that this approach is
the most cost-effective. The first is that most of the likely harmful consequences of climate change are
not new problems but simply the exacerbation of existing ones, so that addressing these
will bring benefits even if there is no further global warming at all. The second reason is
that, unlike tackling emissions, this approach will bring benefits whatever the cause of the
warming, whether natural or man-made. And the third reason that this would be the most
cost-effective way to proceed is that there are benefits as well as costs from global warming.
Globally, the costs may well exceed the benefits - although here in northern Europe it is
quite possible that, over the next 100 years, the benefits will exceed the costs - but it is
clear that a policy of addressing directly the adverse effects enables us all to pocket the
benefits while
diminishing the costs.
What, then, are the principal adverse consequences of global warming?
First and foremost, there is the problem of coastal flooding as sea levels rise.
Sea levels have in fact been rising very gradually for as long as records exist, and even
the IPCC admits that there is little sign of any acceleration. But it could happen, and there is
a clear case for government money to be spent on improving sea defences in low-lying coastal
areas. The Dutch, after all, have been doing this very effectively for 500 years. The
governments of the richer countries can do it for themselves; but in the case of the poorer
countries, such as Bangladesh, there is an obvious argument for international assistance.
A second identified cost of global warming is damage to agriculture and food
production as the climate changes. This is almost certainly exaggerated in the IPCC studies, which
assume that farmers carry on much as before - the so-called 'dumb
farmer' hypothesis. In reality they would adapt by switching to strains or crops better suited to warmer climates, and
indeed by cultivating areas which have hitherto been too cold to be economic; so little
government action would be required.
A third alleged threat from climate change is that of water shortage. In fact,
the volume of water flowing down the world's rivers has increased over the 20th century as a
whole. But in any event, there is massive wastage of water at present, and clearly ample scope
for water conservation measures, including in particular the pricing of water - which
would also help on the farming front.
Addressing these specific consequences is not only far and away the most
cost-effective approach to global warming: it also buys time. Time to learn to understand
better the highly uncertain science of climate change; and time to allow technology to develop
more economic sources of low-carbon energy than we have now. And on precautionary grounds it
may be sensible for governments to use this time to encourage both low-carbon technological
development and its diffusion.
It has to be said that this is not an easy message to get across, not least
because climate change is so often discussed in terms of belief rather than reason.
It is, I suspect, no accident that it is in Europe that
climate change absolutism has found the most fertile soil. For it is Europe that has become the most secular society
in the world, where the traditional religions have the weakest popular hold. Yet people still
feel the need for the comfort and higher values that religion can provide; and it is the
quasi-religion of
green alarmism and what has been termed global salvationism - of which the
climate change issue is the most striking example, but by no means the only one - which has filled
the vacuum, with reasoned questioning of its mantras regarded as a form of blasphemy.
But that can be no basis for rational policy-making.
Lord Lawson is a member of the economic affairs committee of the House of
Lords, which last
year conducted an inquiry into, and published a report on, the economics of
climate change.
Copyright 2006, The Spectator