What are we really arguing about when we argue about climate change?

Books referred to:

Ian Plimer, Heaven and Earth: Global Warming: The Missing Science, UK edition, Quartet Books, 2009.

Christopher Booker, The Real Global Warming Disaster: Is The Obsession With ‘Climate Change’ Turning Out To Be The Most Costly Scientific Blunder In History?, Continuum International Publishing Group, 2009.

The phrase ‘the science is settled’ is regularly used by politicians arguing for meaningful action on climate change. To the majority of the world’s scientists, global warming is a clear and present danger and those who deny it, or argue that its effects will limited or benign, are dangerous lunatics. Nevertheless, an increasing numbers of voters, particularly in the US and the UK, have drifted into the sceptic camp in recent months and years. A Pew Research October survey in the US showed the percentage of people seriously concerned by the climate change issue down from 77% to 65% in two years. An international survey by HSBC showed a fall from 32% to 25% over the past year in the percentage of people from developed markets saying that climate change was the biggest issue that respondents worried about. The overall figure across all 12 countries surveyed fell from 42% in 2008 to 34% in 2009.[*]

A batch of highly successful books from journalists and maverick scientists has provided the intellectual covering fire for this decline. The result of the growing scepticism will be a weakening of national resolutions to take the difficult steps required to shift rich countries away from dependence on fossil fuels.

***

Why, when the tone of urgency from mainstream scientists is getting ever clearer and the research results more worrying by the week, is the sceptic case in ascendancy? I try to argue in this article that the reason is that the scientific arguments for dangerous man-made climate change are somewhat easier to attack casually than most climate scientists admit. Second, the sceptic case runs strongly with the grain of a fierce antagonism to big government and all its works. Many people I talk to have heard the arguments of the sceptics and the deniers, have noted the accompanying rhetoric against politicians and know-it-all scientists and thus feel an immediate kinship with the case against dangerous global warming. We could continue to disregard the opinions of this growing and sizeable minority but I think we need to start dealing with their concerns. To do so does not necessarily involve any step back from a full-hearted commitment to reducing global deforestation and fossil fuel use.

The strange arguments between sceptics and mainstream scientists
The chronicles of the Norsemen suggest that they discovered North America around the year 1000. For centuries the truth of this story was resisted by historians but the discovery of Norse artefacts in the 1960s at the L’Anse aux Meadows settlement in northern Newfoundland gave it firm support. Evidence of iron smelting at this site plus a small number of metal articles convinced most scholars that the Norsemen had lived there, although possibly only for a couple of years.

The Norse people spread widely over the European continent in the tenth and eleventh century to places as far south as Sicily. The spread westward to Greenland and then to North America came as the ice in the North Atlantic melted at the beginning of what we now call the Medieval Warm Period (MWP), which started around 900 and ended abruptly about 1300. Just how warm was the MWP in the higher latitudes of the northern hemisphere? This is a topic that arouses fierce debate among the opposing camps in the debate about climate change. To the sceptics, the evidence is clear that temperatures in the MWP were higher than they are today. The consensus among climate scientists is very different. They say that worldwide rises in the last forty years have pushed typical temperatures well above the MWP. The argument may seen arcane but the debate could not be about a more important issue: if temperatures were higher before we began to burn fossil fuels, and thereby add CO2 to the atmosphere, isn’t this strong evidence that the natural variability of climate overwhelms the impact of adding greenhouse gases?

The hardy Norsemen of a thousand years ago play an important role in this dispute. They seem to have named one part of North America ‘Vinland’. To the sceptics, this is valuable evidence. It shows that the growing of grape vines was possible as far north as L’Anse aux Meadows at the turn of the first millennium. Ian Plimer is a geologist aligned with the anti-global warming camp. His recent and very influential book says artlessly that ‘the Vikings [...] called Newfoundland “Vinland” because of the vineyards there’ (p. 65). Today, no wineries exist within a couple of hundred miles of this Viking settlement and those who say that the warming of the current era is unusual make great play of this fact.[1]

Plimer’s conclusion is far from robust. The village at L’Anse aux Meadows probably functioned as a staging post for Viking vessels on the route between Greenland and warmer areas of North America, and the word Vinland may have referred to an area much further south than northern Newfoundland. In support of this hypothesis, archaeologists have noted that among the finds at the settlement at L’Anse were a small number of nuts that were probably grown in New Brunswick, a long way south down the coast. Wild grapes grow in milder parts of New Brunswick today and some now think that this region – or areas further south – was the original Vinland. Another strand of opinion says that the word Vinland might not be related to vines or wine at all. Instead, some writers suggest that ‘Vin’ means meadow, as it does in many Scandinavian place names. They also persuasively point out that the Norse were probably far more interested in the existence of grass grazing for their cattle than they were in grape vines.

We may never know whether grape vines grew further north during the MWP than they do today. In a sense this may not be important. What is crucial is that because the evidence is arguable, it has allowed both sides of the global warming debate to claim support from the word Vinland. A similar ambiguity exists over the naming of Greenland by Eirik the Red. To the sceptics, the word indicates that this massive island was ‘green’ during the period of warmer temperatures a thousand years ago. Indeed, it seems that every online newspaper article about global warming is followed by at least one comment from a reader that makes this point. But as with Vinland, the issue is more complicated. Go to southern Greenland in summer and the lush green vegetation can run right to the edge of the ice sheets. As children we may have sung hymns about ‘Greenland’s icy mountains’ in our school assemblies but today’s inhabitants are growing potatoes and other temperate crops in sheltered areas.

A second explanation will also appeal to our brand-conscious age. The original Greenland settlement was founded by Eirik the Red after he was exiled from Iceland for murdering a member of the royal family. He used his marketing skills to give the inhospitable destination an attractive name as a way of attracting other settlers to join him on the trip westwards. Does the name Greenland really mean that northern hemispheres were much warmer a thousand years ago? No, but it does provide an element of support, however tenuous, for those who doubt the prevailing orthodoxy that temperatures are higher now than they were then.

With a topic as complex as global warming and a shortage of reliable data, disputes over past temperatures will probably go on for ever. You might imagine that present-day temperatures were the subject of less argument. No, the debates are even more passionate and ill-tempered. The sceptics question everything about the modern record, from the siting of the thermometers through to the problems of measuring temperature accurately at different heights in the earth’s atmosphere. I wanted to focus on just one issue – 1998 temperatures – that fills many pages of the books written by scientists and commentators such as Plimer and Christopher Booker. According to one respectable collection of data based on figures recorded across the seas and land masses of the world, the year 1998 was 0.6 degrees Celsius above the twentieth-century average – and thus about a full degree Celsius above typical temperatures of the beginning of that century.[2] Other equally respectable data suggest that 2005 was a warmer year, but most see 1998 as still the hottest ever twelve-month period. This allows the doubters to suggest that global warming has stopped. In fact, they frequently go further: they say that the world is now cooling rather than warming. The Sunday Telegraph journalist Christopher Booker makes great play with the periods of cold weather experienced by some parts of North America and Europe in the last few years in his sceptical book on climate change.

The particularly high global temperatures of 1998 were probably driven by a strong ‘El Niño’, a period of particularly warm water off the Pacific coasts of Central and South America. In the past, El Niño events seem to have increased average world temperatures and most commentators believe that unusually warm surface water may have driven the 1998 peak. Has the climate cooled since then? It depends on what side of the fence you are on. If you agree with the climate change consensus you note that most temperature records say that each of the last nine years has been hotter than every single year in the twentieth century, bar 1998. The current decade will very probably be substantially warmer than the last one. In other words, 1998 was the aberration, caused by unusual sea surface warmth. The consistently high average global temperatures of the last few years – and I stress the word consistently – mean that this decade will probably be about 0.2 degrees Celsius higher than the 1990s, an observation entirely in accordance with most climate science models. We have recently entered a new El Niño and 2010 temperatures may, or may not, match 1998’s. On the other hand, if you doubt the climate science you respond by noting that the standard forecasts of the IPCC all suggested steady yearly rises in global temperatures – a prediction inconsistent with the record year, i.e. 1998, having occurred over ten years ago. To the sceptics, global warming has stopped since 1998, demonstrating the unreliable nature of the standard scientific view. Christopher Booker writes: ‘in the six years between 2000 and 2006 even the trend line of surface temperatures had not continued to rise, flattening out around an average level more than 0.2 degrees lower than in 1998’ (p. 187).[3]

Whether the debate is about the Medieval Warm Period or today’s temperatures, the data usually allows multiple and conflicting interpretations. The sceptics accuse the climate scientists of ignoring the statistics that don’t support their claims and the scientists respond with open derision towards many of the assertions made by the increasing number of people openly hostile to the global warming consensus. It has become an adversarial and largely pointless argument between people in opposing trenches tossing half bricks at each other.

The scientific debate
Underlying some of the debate is a difference of scientific opinion. The sceptic case can be put as follows. Carbon dioxide is indeed a global warming gas along with water vapour and other trace gases such as methane. All other things being equal, a rise in CO2 concentrations in the atmosphere will increase temperatures. But CO2 is much less important than the standard climate science model says. The blanketing effects of all greenhouse gases hold temperatures about 20 degrees above the level we’d expect to see if the atmosphere was just oxygen and nitrogen.[4] The sceptics say that CO2 is responsible for less than 4% of this natural greenhouse effect.[5] The burning of fossil fuels and the cutting down of forests has so far added about one third to the pre-industrial level of CO2, suggesting that it can only have caused a very small temperature rise. Even a doubling of CO2 concentration from the pre-industrial level won’t add more than a degree Celsius to the average global temperature. This is a relatively small change, the sceptics say, and cannot do much to harm us. In fact, the increase in temperature will actually be less because other changes will damp down the net effect from rising greenhouse gas concentrations. These phenomena are usually called ‘negative feedbacks’. For example, low-level cloud cover might increase as a result of hotter temperatures, blocking solar radiation from arriving at the earth’s surface. For the avoidance of doubt, I should say that these views are held by only a small fraction of the world’s scientists working on global warming and related issues.

In simple summary, the opponents of the climate science consensus tell us that the atmosphere is far less sensitive to increased CO2 than the standard models. The leaders of the movement say that the minor effects of man-made greenhouse gases are swamped by the earth’s natural cycles, such as the modest variability of the sun’s energy output and the long swings in ocean surface temperatures, particularly the Pacific Decadal Oscillation (PDO). (The PDO is currently in a phase that climatologists think is probably reducing global temperatures. Many of the sceptics, and some members of the scientific consensus, therefore see the possibility of broadly stable average temperature readings for the next few years.) The rise in the warmth of the globe since 1945 is just a normal oscillation that shouldn’t cause any alarm. So the sceptics believe that the calls for urgent ‘decarbonisation’ are a huge over-reaction to temperature changes that have happened many times before and have corrected themselves naturally. Hence the importance that the sceptics place on the Medieval Warm Period and its rapid swing into colder conditions after the year 1300.

The conventional view sees the role of carbon dioxide as far more important. Where Ian Plimer and Christopher Booker write of CO2 being a very minor global warming gas, climate scientists say that it contributes a significant fraction of the greenhouse effect. Standard science suggests that a doubling of CO2 from pre-industrial levels will by itself add about 1.2 degrees to global temperatures. And mainstream science also differs from the sceptics by predicting that this figure will be amplified, not damped, by positive feedbacks. For example, as temperature rises, the atmosphere will typically hold more water vapour. Since water vapour is a greenhouse gas, it will add to the warming effect. Scientists typically say that doubling CO2 above the pre-industrial level will add between 2 and 3 degrees to average temperatures. Others are far more pessimistic, saying that the rise may be nearer 6 degrees, i.e. bringing temperatures to a level that would make life impossible over much of the world’s surface.

Conventional science therefore says both CO2 is more important and that increases in atmospheric concentrations will produce amplifying effects that make temperature increases much larger. Rather than assuming that rises in global temperatures will eventually stabilise due to natural braking processes, the majority view of the world’s scientists is that at some point temperature increases become strongly self-reinforcing. For example, the melting of the northern Tundra may trigger rotting of the decayed plant matter that will be exposed to air once the ice has gone, resulting in the emission of large volumes of methane, a gas with much greater warming effect than CO2, although with a shorter residence time in the atmosphere. The results could be truly catastrophic. The sceptics reply by saying that this didn’t happen in the past and so probably won’t happen in the future. They are wrong to be so confident: paleo-climatic evidence shows that temperatures have jerked upwards sharply in the past, possibly because of methane burps arising from the melting of the organic matter currently trapped in permafrost.

Mainstream science will never win over the mavericks. Plimer himself says that ‘the public debate over global warming will never be settled by reason and evidence’ (p. 446). There’ll always be a plausible non-greenhouse explanation for any climate phenomenon. When we cannot even agree on measurements of the world’s temperature for 2008, it is unlikely that we’ll get consensus on what rises we can expect by 2050. Nor will we get any agreement on the impact of these changes on crop yields, water availability, sea level rise, flooding or biodiversity. We should be focusing instead on why so many non-aligned members of the general public, particularly in Britain, have come to believe that global warming is little more than a hoax.

What is really being debated?
The books by Plimer and Booker both conclude with very personal chapters expressing raw pain at the damage they say this hoax is causing. Unusually for books that are about science and scientific method, they devote their conclusions to attacks on what they say are small and tight-knit groups of environmentalists, individual glory-driven scientists, and weak-kneed politicians. The climate science consensus is portrayed as a rigid orthodox ideology with the high priests at the IPCC ruthlessly squashing any form of dissent. Plimer approvingly says the founder of Greenpeace suggests that green movements ‘have been taken over by neo-Marxists promoting anti-trade, anti-globalisation and anti-civilisation’ (p. 437).[6] It won’t surprise the readers of his Sunday Telegraph column that Booker uses similar language about the environmental groups pressing for action. He says that it is a form of organised religion, demanding adherence to the sacred texts (the pronouncements of the IPCC) and an unthinking acceptance of the sayings of the Prophets Gore and Hansen.[7] Both authors suggest improper motives, such as the pursuit money or fame, for some of the people at the centre of what they might call the climate change ‘establishment’. (Booker in particular really loves quotation marks – the word ‘environmentalist’ is rarely used without this contemptuous qualification.)

No wonder their views are gaining currency. They have tapped into a profound hatred of politicians and of others that want to control our lives. The green agenda is seen as yet another way for the state to curtail freedom of action and thought. The environmental NGOs are the future secret police, checking on the temperatures of thermostats and whether we are buying too much beef. Slightly eccentrically, Booker even sees the climate change movement as connected to a campaign for world government. The need for a rapid change in industrial direction – away from basing prosperity on cheap fossil fuels and towards the use of renewable energy – is portrayed as both profoundly expensive and ineffectual. The environmental movement is trying to make us less prosperous, they say, out of a deep hatred of humanity and its works.

Both books repeatedly hammer at what they say is the intolerance of intellectual diversity and quote some highly believable examples of the crushing of dissent. They point to the intellectual exiling of the small number of scientific apostates who have changed their views. They describe what they call the suppression of unorthodox views as profoundly unscientific. By the way, when challenged on this issue, climate scientists tend to respond tersely by saying that their subject will not advance by trying to incorporate theories that are patently and absurdly wrong.

Unfortunately this doesn’t convince the wider population which increasingly sees evidence that governments do suppress dissent, even to the extent of questioning the sanity or motives of those who do not agree with the prevailing orthodoxy. Whether it is a respected scientist who is also a chief government adviser arguing for the legalisation of drugs, or a prison governor suggesting that prison isn’t effective, our leaders do seem to have increasing intolerance for non-conventional views. Climate change is no different. A sceptical electorate watching the walls rising around one orthodoxy after another is right to question whether the standard view of climate change is just another ossified ideology that exists only to protect the interests of a small clique (or ‘arrogant and self-serving priesthood’ as the authors might have put it). It has almost reached the point at which Energy and Climate Secretary Ed Miliband could state that the colour red has a wavelength of about 650 nanometres and a large group would immediately rise up to contradict him. And the regular mention of higher levels of green taxation doesn’t help – it just emphasises that the battle against climate change seems to be quite closely associated with giving governments more control over what we do and how we do it.

Whether we like it or not, we will not get substantive action unless the growing scepticism in the electorate is addressed. This means a much greater willingness to engage in debate and discussion. And a far greater emphasis on showing that a low-carbon future does not have to be impoverished, chilly or restricted. In other words, those with influence need to stress the importance of advanced technology rather than the turning down of the thermostat. The threat of climate change is a society-wide challenge, so it needs to engage those who presently see global warming as yet another burden foisted on them by duplicitous government. We’re past the stage when government and science can simply ignore the sceptics.


Footnotes
[1] The winery at Twillingate in Newfoundland, about 200 miles south of L’Anse, uses fruits such as strawberries for its wine, and not grapes.
[2] I am referring to the temperature series produced by the National Climatic Data Centre, part of the US government National Oceanic and Atmospheric Administration (NOAA).
[3] One punctuation mark extracted (a comma) for ease of comprehension.
[4] Without an atmosphere, the world would be at an average temperature of -18 degrees C. With oxygen and nitrogen, but no global warming gases, the figure is about -6 degrees. Greenhouse gases take it up to about +15 degrees.
[5] Ian Plimer quotes a figure of 3.62% on p. 17 of Heaven and Earth.
[6] These are Plimer’s words and represent his interpretation of what Dr Patrick Moore says in an essay at www.greenspirit.com entitled ‘Environmentalism for the 21st Century’.
[7] James Hansen is a distinguished climate scientist who works for NASA’s Goddard Institute for Space Studies.


[*] These figures have been corrected since the original publication of this article. I had previously misinterpreted the survey results to suggest that the overall figure dropped from 32% to 25%, when in fact this only applied to respondents from developed markets. Thanks to Daniela Hale from HSBC for alerting me to this error. (Thursday 5 November 2009.)



This article was also published on the Guardian Environment Network on Wednesday 4 November 2009.