Download Why (what) do policy makers need to know about uncertainties

Why (what) do policy makers need to know about uncertainties?
Nafees Meah, Department of Energy and Climate Change, UK
Introduction
Most scientists that I know are convinced that climate change is real. That
there is an overwhelming ‘consensus’ of scientists who are convinced of the
same. We can provide ample evidence to justify this belief. Most of us are
happy to sign up to the IPCC key conclusion that:
Warming of the climate system is unequivocal, as is now evident from
observations of increases in global average air and ocean temperatures,
widespread melting of snow and ice and rising global average sea level
And that:
‘most of the observed increase in global average temperatures since the
mid-twentieth century is very likely due to the observed increase in
anthropogenic greenhouse gas concentrations.’
And yet despite this ‘scientific consensus’ the fact is that there are a large
number of people out there who just don’t buy it. No doubt some of them will
be funded by fossil fuel interests. But that’s unlikely to be the case for the
vast majority of people.
Perhaps one of the reasons for this scepticism is the use and abuse of the
term ‚uncertainty‘. This is not surprising if we take a moment to reflect on the
everday meaning of the term ‚uncertainty.‘
If you look at any on-line dictionary definition of uncertainty, you will come up
with something like this:
 Not knowing what to do or believe, or not able to decide about
something;
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 Not known or fixed, or not completely certain
Helpfully the cambridge on-line dictionary also lists a number of synonyms
and equivalent phrases for ‚uncertainty‘:
Uncertainty is....
doubtful
Blow hot and cold
Be in two minds
dubious
irresolute
conflicted
Fence sitter
Hum and haw
Insecure
shilly shally
Sit on the fence
indecision
indecisive
lack of direction
Jury is still out
limbo
unsure
Wish washy
unclear
wobble
My personal favourite is „wishy washy“//
The undue emphasis on uncertainty in climate change science is, i believe, the
cause of an enormous amount of anxiety for many climate change scientists.
It seems to me that loose talk about uncertainty is gnawing at the heart of the
climate change science enterprise.
Climate change „sceptics“ have exploited this anxiety to the full. One of the
claims against the „scientific consensus“ on climate change is that as the
science is all uncertain, then there is no firm basis for collective political
action.
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The response of scientists has generally been one of defensiveness - that is
evident from the „climategate“ affair and in the response to the criticism of
ipcc 4th assessment report for the errors found within it.
I also think that this defensiveness arises from the belief amongst many
scientists that policy makers need clear unambigous statements from them,
on which the policy maker can then make clear and unambigous policy
decisions; taken together with the apparent failure of scientists to provide
those unambiguous statements.
However, I would contend that this is based on an oversimplified picture of the
policy process. Although there are models of policy making which posit a
rational process of agenda setting, evidence gathering, assessment of
options, implementation, evaluation etc., usual presented as a cycle, the reality
is that it is irreducibly „messy“.
contested areas, the normal
In most areas of policy, particularly in
situation is characterised by complexity,
ambiguity and uncertainty - whether it be prison policy or drugs policy.
The key point I want to make is that policy makers deal with uncertainty all the
time. It is the „normal“ condition of the policy process. Further, science by its
very nature is contingent and provisional and cannot provide this elusive
„certainty“ in any case – especially when dealing with complex systems like
the earth system. So in answer to the question of „what policy makers want?“
, I would assert that it is not certainty nor a spurious quantification in saying
one is „50% certain“ about a specific scientific knowledge claim but
confidence in the big picture inferences drawn from the body of climate
change science as a whole.
Confidence ultimately rests on judgements about ‚credibility‘ about a person
or body asserting a knowledge claim.
Climate and other gates’
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Since the revelation in the e-mails from the climatic research unit at UEA at
the end of November last year, there has been a veritable firestorm that has
engulfed the climate science community.
Hot on the heels of this event was the finding that a number of references in
the IPCC reports were wrong. In particular, the reference to the melting of
Himalayan glaciers by 2035.
These have been very hard times for a lot of climate scientists and scientists
more generally. A cursory glance at the blogosphere will show you that there
is a bare knuckle fight going on. The ‘revelations’ from the cru e-mails have
provided the excuse for acres and acres of science new stories.
This is
unprecendented – and not necessarily a bad thing.
‘Climategate’ kicked of a raft of official inquiries in the UK with the objective, in
part, to restore confidence in the science. All of them have now reported their
findings and given CRU, I’m pleased to say, a clean bill of health – except for
the defensiveness.
Sir Muir Russel’s independent review did an interesting thing in showing that
any reasonably capable non-expert could reproduce the CRU, NASA and
NOAA global average land temperature anomaly time series relatively easily,
perhaps the key evidence for global warming, from the raw historical data
available freely from the ncar website and using computer code also readily
available. Any reasonable person would say that this undermines the
allegation of conspiracy and manipulation of the data by the CRU team.
The IPCC errors have themselves generated at least two inquiries. The first by
the Netherlands environmental assessment agency (NBL) which found that
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although the conclusions in the IPCC Working Group II report were generally
sound, there was a propensity to ‘accentuate the negative’ in the summary for
policy makers.
The second inquiry, by the InterAcademy panel, made a number of
recommendations about the governance of the IPCC but also criticised the
way scientific uncertainties were dealt with by the three working group
reports. I guess this audience is well acquainted with these issues.
Will these reports allay the concerns of the public and bring the sceptics on
board? I have my doubts.
I think that an urgent priority must be to reclaim the term ‘sceptic’ and restore
it to its role as a vital element of scientific progress. It is or should be ok to be
‘sceptical’ about some proposition of science which are held out as being true
so long as you keep an open mind. It is the default mode of operation in
science.
Where ‘climate change sceptics’ part company with genuine
scientific ‘sceptics’. They are not prepared to change their minds in the face
of new evidence.
Climate science in the media
In a recent book by Ben Goldacre’s called ‘Bad science’, he posited a variant
of C. P. Snow’s two cultures hypothesis to explain why the media deal with
science stories the way they do.
His argument is basically that the people who run the media in the UK are
humanities graduates with little understanding of science, who wear their
ignorance as a badge of honour. He suggests that perhaps deep down they
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resent the fact that they have denied themselves access to the most
significant developments in the history of western thought, as a result there is
an attack implicit in all media coverage of science.
In their choice of stories, the way that they cover them, the media create a
parody of science.
According to Goldacre, the media portrayal of science is
as a set of groundless, incomprehensible, didactic truth statements from
scientists, who themselves are socially powerful, arbitrary, unelected figures.
They are detached from reality; they do work that is either wacky or
dangerous, but either way, everything in science is tenuous, contradictory,
probably going to change soon and...’hard to understand’. Having created the
parody, the newspaper commentators then attack it, as if they were critiquing
what science is about.
You can clearly see this perspective at work in the recent media coverage of
Climategate and Glaciergate in the UK. Although I think that Ben Goldacre is
essentially right, he does miss out an important dimension. Scientists and
especially climate change scientists have colluded in constructing this parody
of science.
The shrill media coverage in the UK media has had an impact on public
perception of climate change. Although it is difficult to say whether this will
last.
But let’s look at the recent polling data more closely. Two polls of most
relevance, comparing opinion before and after ‘Climategate’ (Populus for BBC
– compared Nov 09 to Feb 10; Ipsos Mori for guardian - compared Jan 09 to
Jan 10)
From Populus (for BBC) – compared opinion in November 2009 and February
2010. In February, people were more likely to say climate change was not
happening (25%, only 17% before).
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Of those who accepted climate change was happening, fewer believed it was
man-made. The number saying that it’s ‘established fact’ that climate change
is mostly man made dropped from 50% to 34%. More were likely to say ‘it’s a
widespread theory, but not conclusively proven – that’s column two – up from
39% to 50%) column three is people who said this was ‘environmentalist
propaganda’ – up from 9% to 14%)
The poll asked people whether they had heard of flaws in the science – 57%
had. But more people had heard about the exceptionally cold winter.
Of those who had said they had heard about ‘flaws or weaknesses in the
science’ the vast majority said it had not changed how they feel about the
risks of climate change. 11% said they were less convinced of the risks of
climate change as a result, but 16% said they were actually more convinced of
the risks of climate change afterwards.
All this signals that it’s not clear cut how these events have shaped public
perception…but it’s clear there is a great deal of confusion around, and that
these events have not helped.
It turned out in retrospect that it was a mistake to assume that the scientific
case for climate change had been made. Or at least, to assume that to the
layman, the ‘consensus’ of experts had any meaning at all. There are interests
that do not want to see the truly massive changes that will be required to our
fossil fueled infrastructure and changes in behaviour needed for any
meaningful action on climate change. This is true both in the developed and in
the developing world - albeit for different reasons. So it should not have been
surprising that there was push back on the scientific ‘consensus’.
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Certainty and uncertainty: unpacking the issues
I said earlier that scientists and particularly climate scientists had colluded,
whether consciously or unconsciously, in constructing the parody of science
that’s represented in the media.
I say this partly because the argument one sees from some climate change
scientists takes the form:
If ‘x’, then you must do ‘y’
So the critical question becomes whether you
‘believe in climate change?’
This kind of reasoning assumes that there is a thing out there called ‘climate
change’ and one has to commit to that belief.
It becomes
a question of
ontology. (much like the ontological arguments for the existence of god!)
In some ways that is the way that the IPCC Fourth Assessment Report has
been publicly presented. Almost as if it were a tablet of stone. The ‘truth’ as
spoken by international scientists. Wining the Nobel Prize was, I think a mixed
blessing. As a result, ‘we’/‘you’ have to change your ways and do it quickly.
Of course, taking this line positively invites being attacked and undermined.
In my view, this kind of approach misconceives the practice of science. The
important question is
‘how do we know what we know?’
A question of
epistemology. It is true that there is a consensus amongst climate scientists
on global warming and rising sea levels. However, there is disagreement and
uncertainty about the details.
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This is science at the cutting edge; science as
practiced. As more knowledge is acquired, explanations are and have to be
revised.
Moving from global warming to attribution of it to GHG emissions; from
emissions to atmospheric concentrations; from atmospheric concentrations to
temperature rise; from temperature rise to climate change; and from climate
change to climate change impacts is a complex scientific story. Each step has
an associated uncertainty. There is a cascade of uncertainty. We get a handle
on this uncertainty is through better understanding of the physics of the
climate system, systematic observations and modelling future states of the
climate and their impacts.
However this cascade of uncertainty is not the same as saying we don’t know
anything. As Donald Rumsfeld has now famously said:
“…there are known knowns; there are things we know we know. We also
know there are known unknowns; that is to say we know there are some
things we do not know. But there are also unknown unknowns—the
ones we don’t know we don’t know.”
Therefore, it seems to me that scientists ought be bolder in speaking with
confidence of things they know about. Clearly not all knowledge claims are on
a par. But I don’t think there any point in hedging and qualifying by assigning
single numbers to knowledge claims (as in “we’re 50% certain of ‘x’). I don’t
think it helps with communicating what we know about the science. One thing
is for sure, that is that science does not and cannot provide absolute certainty
– hopefully everyone appreciates that.
The activity of much of ‘normal’
science however is about reducing uncertainty.
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However, some of this uncertainty is irreducible.
Our models may be
incomplete. Our understanding of natural systems may be incomplete. Our
understanding of social responses are definitely incomplete.
However, incomplete knowledge is the normal state of affairs when we all
make decisions about the future. That includes governments, businesses and
individuals. We do it all the time.
At this point, climate change ceases to be a scientific problem. Claims of
scientific knowledge do not automatically lead to prescriptions for action.
Therefore, we should be careful not to fall into the habit of saying
If ‘x’, then you must do ‘y’.
Science and public policy
Turning now to public policy and how it is made. In particular, to the ‘ask’ of
policy makers of scientists in those areas where scientific input is
indispensible to ‘good’ policy -
environmental management is the classic
example of such an area.
If we start from the premise that the objective of public policy is to prevent
harm to and increase welfare of citizens, then the policy process essentially
boils down to working through the arguments for particular actions from a set
of alternative options to achieve specific ends.
Notwithstanding the various theories that exist about public policy and how it
is made, my experience is that most ‘policy makers’ I know believe themselves
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to be rational. Also scientists when they engage with the policy process, as
they do in the IPCC, do so on the basis that they are engaging in a rational
process.
According to the rationality model, public policy making involves assessing all
the evidence; considering all the options; considering the costs and benefits
of the different options; and choosing the optimal alternative. The output of
the process is usually either a regulation or a tax measure or a subsidy
intended to change behaviour.
Often the process is presented as a cycle and the expectation is that as new
evidence comes along or some evaluation of a policy intervention is carried
out there will be some revision.
It is important to recognise that for this idealised process to work, the policy
maker has to has to have a mental model of how the world works. Also the
policy maker by definition adopts an instrumentalist attitude towards
knowledge claims.
This idealised model of policy formulation is clearly a fiction. It may be a
useful fiction – but its limitations need to be recognised by scientists engaging
in the policy process.
Public policy issues are normally complex, occur in rapidly changing and
often turbulent circumstances, are often characterised by uncertainty and
usually involve conflict between different interest groups.
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Nonetheless, decisions still have to be made and those making the decisions
are accountable to the public for giving reasons for those decisions.
The cliché is that policy makers demand ‘hard facts’ from scientists on which
to base firm policy decisions. They are, the cliché goes, not interested in
hedging and qualifications that scientists with their more cautious nature are
prone to add to their statements. It is said that what policy makers get from
the scientists is then oversimplified and sometimes misrepresented.
There may be some truth to this cliché. However, although it is clearly
necessary to explain the uncertainties in the science to policy makers,
scientists should not assume that these are then not understood and the
policy makers are not listening. It may simply be that many different kinds of
‘uncertainties’ have to be taken into account in the process of policy
development - scientific uncertainties being just one.
Or it may be that the
‘science’ is being used to justify a position that reflects the decision makers
values. However what policy makers do want are the big picture inferences
from the science to establish their mental models of how the world works.
Also given that there are many kinds of uncertainties in the process of policy
development, if all one hears about is ‘scientific uncertainty’, particularly in
climate change science, then one should not be surprised that it comes back
to haunt you and people start to question the validity of the science itself.
There are of course well established ways that policy processes can deal with
making decisions in the face of scientific uncertainty.
We can apply the
precautionary principle or adopt strategies that are resilient to a range of
different future scenarios or we can choose adaptive strategies that can be
modified as one learns more about the issues at hand and how the future is
unfolding.
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Importantly, we can manage uncertainty through a risk framework where risk
is traditionally formulated as a combination of probability and consequence of
climate change impacts occurring.
If managing the risk to a locality from climate change is the operational
response of society, then it seems to me that at this point the science of
climate change stops being intangible and becomes ‘real’ to the layman or
non-expert. [on the other hand, perhaps managing the risk through mitigation
at the global level is destined to remain an abstraction for most people. ]
At this point, climate change scientists have to enter a dialogue with other
actors – lawyers, doctors, engineers etc and - most importantly - with the
community. Until that happens, talk about climate change remains an ‘elite
discourse’. If people are going to change their behaviour, they are going to
have to engage on a practical level.
That is why I believe the adaptation
agenda is so crucially important.
Conclusion
First, we need to move away from promoting the idea of climate science as a
body of universal ‘facts’ delivered from upon high by remote authority figures.
Second, where science has a public policy role, then, expect the scientific
evidence to be challenged.
It’s normal. When this happens, then the best
policy is to be open and transparent but scientists need to be prepared to
defend their findings.
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Finally, I would assert that it is not certainty nor a spurious quantification of
saying one is „50% certain“ (sic) about a given scientific knowledge claim that
matters to policy makers but confidence in the big picture inferences boldly
stated and drawn from the science as a whole. It does not follow that from
that confidence expressed by the scientific community on a set of
propositions about the state of world (or the future world) that action should
necessarily follow.
What happens next is an irreducibly social process in
which the scientific community/ communities is/are but one set of actors,
albeit important actors.
Nafees Meah
October 2010
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