The appliance of science

The appliance of science

Politicians and the public look to scientists to explain the causes of
climate change and whether it can be tackled - and they are queuing up to
deliver. But, asks Mike Hulme, are we being given the whole picture?
Mike Hulme
Wednesday March 14, 2007
Guardian
Climate change is happening, but it appears that science is split on what to
do about it. One of the central reasons why there is disagreement about how
to tackle climate change is because we have different conceptions of what
science is, and with what authority it speaks - in other words, how
scientific "knowledge" interacts with those other realms of understanding
brought to us by politics, ethics and spirituality.
Two scientists - one a climate physicist, the other a biologist - have
written a book arguing that the warming currently observed around the world
is a function of a 1,500-year "unstoppable" cycle in solar energy. The
central thesis is linked to evidence that most people would recognise as
being generated by science. But is this book really about science?
It is written as a scientific text, with citations to peer-reviewed
articles, deference to numbers, and adoption of technical terms. A precis
of the argument put forward in the book by Fred Singer, an outspoken critic
of the idea that humans are warming the planet, and Dennis Avery is that a
well-established, 1,500-year cycle in the Earth's climate can explain most
of the global warming observed in the last 100 years (0.7C), that this
cycle is in some way linked to fluctuations in solar energy, and because
there is nothing humans can do to affect the sun we should simply figure
out how to live with this cycle. We are currently on the upswing, they say,
warming out of the Little Ice Age, but in a few hundred years will be back
on the downswing. Efforts to slow down the current warming by reducing
emissions of greenhouse gases are at best irrelevant, or at worst damaging
for our future development and welfare.
This, of course, is not what the fourth assessment report of the UN
Intergovernmental Panel on Climate Change (IPCC) said a few weeks ago. The
report from its climate science working group concluded that it is likely
that most of the warming of the last 50 years has been caused by rising
greenhouse gas concentrations and that, depending on our actions now to
slow the growth of emissions, warming by 2100 will probably be between
about 1.5C and 6C.
The upper end of this range is almost an order of magnitude larger than the
warming that Singer and Avery suggest is caused by the 1,500-year cycle. So
is this a fight between scientific truth and error? This seems to be how
Singer and Avery would like to present it - "science is the process of
developing theories and testing them against observations until they are
proven true or false".
Means of inquiry
At one level, it is as simple as this. Science as a means of inquiry into
how the world works has been so successful because it has developed a
series of principles, methods and techniques for being able to make such
judgments. For example, we now understand the major transmission routes for
HIV/Aids, that smoking injures health, and that wearing seat belts saves
lives.
And so it is with climate change. Increasing the concentration of greenhouse
gases in the atmosphere warms the planet and sets in motion changes to the
way the weather is delivered to us, wherever we are. Science has worked
hard over a hundred years to establish this knowledge. And new books such
as Singer and Avery's, or opinion pieces in the Daily Mail, do not alter
it.
So far so good. Deploying the machinery of scientific method allows us to
filter out hypotheses - such as those presented by Singer and Avery - as
being plain wrong. But there are two other characteristics of science that
are also important when it comes to deploying its knowledge for the benefit
of public policy and society: that scientific knowledge is always
provisional knowledge, and that it can be modified through its interaction
with society.
That science is an unfolding process of discovery is fairly self-evident.
The more we seem to know, the more questions we seem to need answering.
Some avenues of scientific inquiry may close off, but many new ones open
up. We know a lot more about climate change now than 17 years ago when the
first IPCC scientific assessment was published. And no doubt in another 17
years our knowledge of how the climate system works and the impact that
humans have made on it will be significantly different to today.
Yet it is important that on big questions such as climate change scientists
make an assessment of what they know at key moments when policy or other
collective decisions need to be made. Today is such a time.
But our portrayal of the risks of climate change will always be provisional,
subject to change as our understanding advances. Having challenges to this
unfolding process of discovery is essential for science to thrive, as long
as those challenges play by the methodological rule book that science has
painstakingly written over many generations of experience.
The other important characteristic of scientific knowledge - its openness to
change as it rubs up against society - is rather harder to handle.
Philosophers and practitioners of science have identified this particular
mode of scientific activity as one that occurs where the stakes are high,
uncertainties large and decisions urgent, and where values are embedded in
the way science is done and spoken.
It has been labelled "post-normal" science. Climate change seems to fall in
this category. Disputes in post-normal science focus as often on the
process of science - who gets funded, who evaluates quality, who has the
ear of policy - as on the facts of science.
So this book from Singer and Avery can be understood in a different way: as
a challenge to the process of climate change science, or to the values they
believe to be implicit in the science, rather than as a direct challenge to
scientific knowledge.
In this reading, Singer and Avery are using apparently scientific
arguments - about 1,500 year cycles, about the loss of species, about
sea-level rise - to further their deeper (yet unexpressed) values and
beliefs. Too often with climate change, genuine and necessary debates about
these wider social values - do we have confidence in technology; do we
believe in collective action over private enterprise; do we believe we
carry obligations to people invisible to us in geography and time? -
masquerade as disputes about scientific truth and error.
We need this perspective of post-normal science if we are going to make
sense of books such as Singer and Avery's. Or indeed, if we are to make
sense of polar opposites such as James Lovelock's recent contribution The
Revenge of Gaia, in which he extends climate science to reach the
conclusion that the collapse of civilisation is no more than a couple of
generations away.
The danger of a "normal" reading of science is that it assumes science can
first find truth, then speak truth to power, and that truth-based policy
will then follow. Singer has this view of science, as do some of his more
outspoken campaigning critics such as Mark Lynas. That is why their
exchanges often reduce to ones about scientific truth rather than about
values, perspectives and political preferences. If the battle of science is
won, then the war of values will be won.
If only climate change were such a phenomenon and if only science held such
an ascendancy over our personal, social and political life and decisions.
In fact, in order to make progress about how we manage climate change we
have to take science off centre stage.
This is not a comfortable thing to say - either to those scientists who
still hold an uncritical view of their privileged enterprise and who relish
the status society affords them, or to politicians whose instinct is so
often to hide behind the experts when confronted by difficult and genuine
policy alternatives.
Two years ago, Tony Blair announced the large, government-backed
international climate change conference in Exeter by asking for the
conference scientists to "identify what level of greenhouse gases in the
atmosphere is self-evidently too much".
This is the wrong question to ask of science. Self-evidently dangerous
climate change will not emerge from a normal scientific process of truth
seeking, although science will gain some insights into the question if it
recognises the socially contingent dimensions of a post-normal science. But
to proffer such insights, scientists - and politicians - must trade
(normal) truth for influence. If scientists want to remain listened to, to
bear influence on policy, they must recognise the social limits of their
truth seeking and reveal fully the values and beliefs they bring to their
scientific activity.
*** of weakness
Lack of such reflective transparency is the problem with "unstoppable global
warming", and with some other scientific commentators on climate change.
Such a perspective also opens a *** of weakness in the authority of the
latest IPCC science findings.
What matters about climate change is not whether we can predict the future
with some desired level of certainty and accuracy; it is whether we have
sufficient foresight, supported by wisdom, to allow our perspective about
the future, and our responsibility for it, to be altered. All of us alive
today have a stake in the future, and so we should all play a role in
generating sufficient, inclusive and imposing knowledge about the future.
Climate change is too important to be left to scientists - least of all the
normal ones.
· Mike Hulme, a professor in the school of environmental sciences at the
University of East Anglia and the founding director of the Tyndall Centre
for Climate Change Research, is writing a book, entitled Why We Disagree
About Climate Change
· Unstoppable Global Warming - Every 1,500 Years, by S Fred Singer and
Dennis T Avery, is published by Rowman & Littlefield (£21.72). The Guardian
and Observer Climate Change Summit will take place in June 2007. For more
details visit guardian.co.uk/climatesummit
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