Tuesday, March 1, 2016



This material was originally prepared for The Oxford Magazine and published in 2015

The threat

Both the science of CO2 related climate change, and the dangers and dilemmas it poses for mankind, are easy to state.  Modern economies still depend on oil, gas and coal for their large energy needs, resulting in huge emissions of the most important greenhouse gas, carbon dioxide (CO2).  Together with other greenhouse gases (GHG), and in the absence of other natural mechanisms to re-absorb the CO2 or stabilise Earth’s climate, higher atmospheric concentrations of CO2 will result in a warmer planet, a major consequence of which is significant climate change. Unlike water vapour, an important natural GHG, but one whose atmospheric concentration tends to be self limiting or self stabilising through precipitation as rain, CO2 and some of the other man-made GHG are essentially cumulative.  

 The timing, scale and distribution of GHG induced climate change are part of an immensely complex set of interacting physical and biological processes that make up the world in which we live. This makes it difficult to know exactly how and when change will affect temperature and rainfall in particular parts of the world, although, as we gather more and more information, the science is becoming increasingly confident on at least some of these questions.  The further consequences in terms of effects on agriculture, water resources, national economies and mass migration are even harder to predict.  But there is little comfort in that uncertainty. Those possible consequences that can be anticipated seem certain to provoke more competition for land, water and other resources, increased global migration, and the potential for conflict that stems from all of these.

 It is also quite clear that there are very substantial risks of seriously adverse or even catastrophic outcomes.  The greater the warming, the higher the probability that we move well beyond relatively small changes in climate, to which adaptation might be relatively easy, even if expensive, into much more severe or even catastrophic changes in our shared global environment, for which available means of adaptation will not be adequate.  Needless to say these changes would impact first and most severely on the poorest and least able to cope.

The perfect storm of political and policy problems

The challenges of dealing with climate change present a possibly unique combination of factors that play to several human weaknesses, whether at an individual or collective political level, and make effective responses to the problem difficult. They include the following.

The first factor is that the problem is essentially global, as gases, and climate, are not contained within national or regional boundaries.  Collective agreement and action is therefore a fundamental precondition for any effective policy.  As with other much less dangerous issues, collective agreements are often hard to achieve nationally. They are even harder to achieve on a global scale, and in relation to commodities of huge economic importance associated with substantial vested interests of all kinds. Action on climate may be in everyone’s collective interest but it is in no-one’s individual interest.

The second factor is the long time lag between cause and effect. Thermal inertia means that even the “first round” and more predictable consequences of a given increase in GHG are only fully worked through over periods measured in decades, with consequential effects such as rising sea levels that will continue over much longer periods and are not reversible other than on geological timescales, even if atmospheric CO2   concentrations are stabilised or brought down.  This naturally conflicts with the myopic nature of much political debate and our ingrained human tendencies to ignore or play down risks that currently seem quite distant in time.

It also serves to introduce the third factor, the irreversibility of current emissions of CO2, which does not decay in the atmosphere and is only removed very slowly, if at all, in the natural carbon cycle. It is the equivalent of a centrally heated room where the radiator can only be turned up, not down, but the room temperature responds only slowly to changes in the radiator setting.  We currently have no known means of extracting CO2 at reasonable cost (the artificial “carbon tree”), nor can we have any confidence that such a technology can or will be developed.  In the absence of low cost extraction, this means that fuel choices made now have irreversible consequences. Without action to curtail CO2 emissions, there is an alarming prospect that, by the time we observe actual warming, we will already have baked in a much larger amount of unavoidable future warming and associated climatic change. At a recent presentation in Oxford, Thomas Stocker of the Physics Institute, University of Bern, and co-chair of the Intergovernmental Panel on Climate Change (IPCC), estimated that committed peak warming rises 3 to 8 times faster than observed warming.

 A fourth factor is the nature of the risks and uncertainties involved in any attempt to anticipate the future.  A common observation of human psychology is that most of us find it difficult to make rational and consistent decisions between different types of risk, even if the risks themselves are in principle well understood.  From a rational perspective, the long term threat from climate change is orders of magnitude worse than that of an accident in civil nuclear power, but that has not prevented a German government, with Green support, from calling a nuclear moratorium and building new coal-fired stations, the worst possible option in relation to CO2 emissions.

In the case of climate science, and even though the fundamental influences on climate are increasingly well understood, there have been enough uncertainties relating to specific details and consequences to allow sceptics, without real evidence, to create the impression that the science is of dubious reliability as a basis for policy. So this fourth deadly ingredient is perhaps our inadequate grasp of risk and uncertainty, or at least our collective inability to comprehend the reality of what the climate science is with confidence describing, and failure, in the eyes of some people at least, of the science to provide a sufficiently clear and convincing narrative around a very complex problem.

 Finally these problems are compounded both by the nature of the particular vested interests threatened by any action aimed at reducing the use of fossil fuel, and by the central role of energy in the production and consumption enjoyed by modern economies.  Some vested interests are obvious.  Nations rich in fossil fuel reserves, especially oil, have a clear incentive to deny the problem.  Distinguished Oxford climate scientist Sir John Houghton, a former Oxford professor of atmospheric physics, co-chair of the Nobel Peace Prize winning Intergovernmental Panel on Climate Change's (IPCC) scientific assessment working group, and lead editor of first three IPCC reports, describes this very clearly in his autobiography.  Saudi and Kuwaiti representatives in the IPCC went to great lengths in their efforts to weaken the conclusions of the IPCC Second Report, and to attribute or exaggerate uncertainty at every opportunity. Sir John also details a variety of dirty tricks, dishonesty and sophistry deployed by other parties with a major vested interest in denying the reality of the climate science.

 And of course as energy consumers or as taxpayers we have own vested interests in not changing our habits of energy use, and in avoiding some of the short term costs of mitigating future problems, even if these are, as will be argued below, these are relatively small in relation to the scale of the dangers they aim to mitigate. The US has long been the world’s most profligate user of oil, coal and gas, and has in the past shown a corresponding reluctance to recognise the issue. China, for whom even the per capita carbon footprint now exceeds the European average, has taken a path of rapid coal fuelled economic expansion as it strives to develop.

 These five factors also reinforce one another.  Vested interests have proved anxious to encourage or exploit any perception of uncertainty in the science, even if this largely relates to the quantum of damage rather than to fundamental understanding of the physical processes and the risk. The long time delays between cause and effect made it easier for sceptics to suggest that the science was mistaken or at least that the risks are exaggerated.  The dependence on global agreement, and action by all, is a disincentive to unilateral action within one country, or even within such a block as the EU.  Long time lags encourage us to dismiss seemingly distant risks, and make us reluctant to incur current costs for future protection.  Irreversibility amplifies all the dangers of delay.

 Confidence in the science

 These dangers and difficulties highlight the scale of the challenge, but of course they also place  a great weight on the confidence that we can place in the science.  This means not just establishing the best available science, but even more on understanding the nature of its certainties and uncertainties, and their implications for understanding the dangers we face.  So it is perhaps worth reiterating what we know.

 The first part of the science is very clear.  An increase in CO2 does, in the absence of other factors, cause a warming in the atmosphere. This, like most of the building blocks of climate analysis, is not a matter of scientific conjecture, or a “Karl Popper” hypothesis  like “dark energy”, that has a real chance  of being overturned as science advances. It is for all practical purposes a fact established by 19th century physics.  A priori we should be worried.

But climate is a product of a whole set of complex phenomena and processes, not least the natural carbon cycle, in which plants and oceans release and absorb atmospheric carbon every year, and whose size dwarfs even the very large scale of annual human CO2 release.  It was therefore possible to hope and plausible to argue, when we first began to examine climate change seriously, that there might be feedbacks within these complex processes which would have the effect of dampening any changes and create a built-in tendency for climate to stabilise.

Candidates for these helpful negative feedbacks included increased re-absorption of carbon within the natural carbon cycle, for example through increased plant growth associated with increased CO2 concentration, and reduced concentrations of water vapour (a powerful GHG) or changes in cloud cover. Unfortunately there is so far little evidence for negative feedbacks which will stabilise our climate.  Measured CO2 is increasing, so natural re-absorption is not happening on a sufficient scale. At the same time there is increasing concern about dangerous positive feedbacks, such as reductions in polar ice cover, reducing the reflection of sunlight, and melting permafrost which releases methane, another GHG. It is of course possible that some new factor, not previously investigated, will turn up, but it would seem foolhardy to rely on such a happy accident. It is not the kind of foolish risk taking that would be countenanced in most human activities.

Of course the final irrefutable proof that actual man-made climate change is an existential problem, and not just a distant threat, comes only with observed actual warming.  Initially that may have been difficult to disentangle from natural variability and natural cycles, such as El Nino, in Earth’s climate. And further measurement problems arise in determining how much of the additional heat is being taken up at a given time in the different levels of atmosphere and in the oceans.  However in spite of these difficulties the evidence of a steady decade on decade increase in temperature, corresponding to the past acceleration of CO2 emissions and enhanced concentration, is now incontrovertible and has not so far been challenged by any serious science.

 Arguments and inadequacies in meeting the political challenge

For anyone concerned with these issues, one of the most frustrating features of the debates on climate policy has been the argument that we cannot afford the cost of actions to mitigate climate change.  These are generally estimated at around one or two percent of GDP, substantial amounts, but comparable to the shocks and changes imposed on national economies by the oil price shocks of recent decades, which have for developed economies been easily accomodated. Similar shocks are regularly imposed by shifts in government spending patterns, let alone the cost of the post 2008 financial sector induced recession, which is estimated to have sliced perhaps fifteen percent off national income, with a corresponding impact on living standards. Expressed in other terms, building up to an expenditure of an additional 1-2 % per annum of global GDP on mitigation could, by 2050, merely amount to reaching the same standard of living a few months later.

Nor should the availability of investment funds, or their cost, be a constraint. Globally, capital has rarely been so plentiful or so cheap. Its deployment in the energy sector, for “essential” investment in low carbon “utility” and infrastructure projects, should be an intrinsically low risk investment, implying a low cost of capital. Failure to secure investment capital on reasonable terms can only result from poor or absent policy frameworks, policy uncertainty or lack of policy commitment by governments. Nothing better demonstrates the economic feasibility of substantial investment in CO2 reduction, or “decarbonisation”, than the French achievements of the 1980s and 1990s, giving them a much lower carbon footprint than most of Europe, and cheaper electricity as well.  The French achievement was based on nuclear, but its real message is that large scale transformative change is perfectly feasible without adverse economic consequences.

 At the same time we should also question the extent to which global policies are even beginning to treat this subject seriously. A simple truth for policy makers is that anti-social activities, or those that cause general damage, should suffer penalties, and should not be encouraged by subsidies. Yet the International Energy Agency (IEA) estimates that the global subsidies for fossil fuel production and consumption still amount to some 500 billion dollars per annum, equivalent to a subsidy of over 100 dollars per tonne of CO2 emitted into the atmosphere.  The European Union, which has at least made a first stab at penalising emissions and is therefore ahead of much of the world, but has produced a carbon price of less than 10 dollars per tonne, wholly insufficient to incentivise low carbon investment on the scale required. The global disparity between subsidies and penalties is very evident.


 Our conclusions should be very simple. The issue is a proven threat, posing potentially extreme dangers to the global community. Early action carries a double benefit in postponing adverse outcomes, and improving options both for mitigation and adaptation, but is so far lamentably absent. Primacy of policy on climate is essential for the future of humanity, even if this is sometimes at some limited short term detriment to other objectives. 

 Fortunately there are signs that the two largest emitters, the US and China, are now appreciating the need for much more effective action. The EU and the UK, whatever criticisms might be levelled against their application of policy, have already shown at least some degree of leadership and responsibility. The UK, with its 2008 Climate Act, was first in embodying emissions targets in law.

 All this attached a great weight to the 2015 climate negotiations in Paris, under the auspices of the United Nations Framework Convention on Climate Change (UNFCCC). The summit achieved some positive progress, but extremely challenging tasks remain and have never seemed more important.

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