Consensus en controverse in het klimaatdebat

Culturele context en epistemologische aspecten.

Emil Røyrvik, verbonden aan SINTEF, het grootste onafhankelijke onderzoeksinstituut van Scandinavië, dat is gevestigd in Trondheim, Noorwegen, heeft onlangs een uitstekend rapport geschreven over het 'slagveld' van het klimaatdebat. Hierin wordt onder meer aandacht geschonken aan de verschillen in de maatschappelijke opvattingen van voor– en tegenstanders van de menselijke broeikashypothese (AGW = 'Anthropogenic Global Warming') en wordt ingegaan op de epistemologische aspecten van het debat.

Ik pik er een aantal krenten uit:

The report positively concludes that an alleged near unanimous scientific consensus on AGW, that “the science is settled”, is overstated. The report finds a robust, critical scientific discourse in climate related research, yet it highlights that a “consensus-building” approach to science might represent a politicised and unscientific belief in science – a belief in tension with the ethos of “normal science”.

The report calls for a continuing questioning, critical, and undogmatic public debate over man-made global warming, and a clearer separation between science and policy.

The debate about man-made global warming is literally a hot topic. In fact it’s a discourse, and an empirical prospect, as some would argue, with quite a deadly intensity. This is a report about that debate. The title of the latest book by one of the central scientists in this field is telling: ”The hockey stick and the climate wars” (Mann 2012). This alleged ”climate war” is a scientific, political, economic, social and moral public field that is co-constructed and intersects in numerous ways, and which, to some extent at least, is characterized by the rhetoric of apocalypse, war and the communicative logic of the military trenches....

The alarmist repertoire uses an inflated language, with terms such as “catastrophe”, “chaos” and “havoc”, and its tone is often urgent. It employs a quasi-religious register of doom, death, judgement, heaven and hell .

Likewise, the widely popular “tipping point” metaphor signifies the possible coming of sudden apocalypse.

The goal of this report is to enter this more or less inhospitable battlefield and take stock of the debate about anthropogenic (man-made) global warming. This will be done by both describing and counting the particular actors, activities and technologies (of both enchantment and production) performing on the scenes of this “theatre of war”, and also by bringing to the table a more distanced and analytical perspective of the field as such, using as a guiding metaphor the (hopefully) neutral UN-observers’ approach to zones of conflict and tension.

The zone we are entering here and its particular mix of morality, science, politics, and polemics can certainly be explosive, confusing, and condescending.

De auteur neemt onder meer stelling tegen de opvattingen van zijn landgenote, de voormalig Noorse premier Gro Harlem Brundtland, die vooral bekend is van het naar haar genoemde rapport over duurzaamheid.

In a 2007 speech before the UN Commission on Sustainable Development, Gro Harlem Brundtland, the UN Secretary General’s Special Envoy on Climate Change (and also former Prime Minister of Norway, and former Director-General of the World Health Organization) conveyed the mixture of politics, polemics, science and morality when she, in relation to global warming, famously stated that: “So what is it that is new today? What is new is that doubt has been eliminated. The report of the Intergovernmental Panel on Climate Change is clear. And so is the Stern report. It is irresponsible, reckless and deeply immoral to question the seriousness of the situation. The time for diagnosis is over. Now it is time to act.”

This statement has several significant and problematic aspects that will be discussed in this report. Has doubt been eliminated in the case of anthropogenic (man-made) global warming? Is it possible to eliminate doubt, and are efforts to do so pursuits pertinent to science and democracy in open societies? Is it immoral and reckless to question and doubt? The Brundtland statement displays both explicitly and implicitly key premises upon which the debate on global warming is being played out, and this report seeks to unfold some of the most important of these premises.

Enkele conclusies:

Based on the present review of this debate there are several conclusions to be drawn. The first and simplest one is that considered as an empirical statement, the assertion that “doubt has been eliminated” on AGW is plainly false. Although as documented the level of agreement in the scientific literature that AGW is occurring is quite extensive, the magnitude of dissent, questioning and contrarian perspectives and positions in both scientific discourse and public opinion on the question of AGW evidently contradicts such a proclamation.

The second conclusion is that the scientific debate may be considered healthy. The levels and types of disagreement crosscuts most camps and categorizations, so that a presentation of two – sided war with a 97 – 98 % majority consensus and 2 – 3 % group of sceptics and “deniers” is flawed. At the level of scientific exchange, there is in the climate science s an ongoing discussion and organized critique that seems to a large extent (with arguably some major exceptions as highlighted in the “climategate ” affair) to be working as “normal science” should.

The allegation that the science of AGW is settled to such a degree and cohesion that the debate can be closed, contradicts the findings in this report. There are multiple on – going debates and questioning , also in mainstream scientific outlets, even on such fundamental issues as whether the greenhouse warming effect is a reality or a fiction; if it is scientifically meaningful at all to talk about a global temperature; if the significant warming that seem s to have happened since the Little Ice Age in the perspective of longer timescales can be considered extraordinary ; the significance of other sources, such as the sun, on climate change; if warming means better or worse conditions on earth; and the extent to which man contributes to the changing climate of earth. ...

It is not difficult the consent to the comments by Mike Hulme, professor of climate change in the School of Environmental Sciences at the University of East Anglia and a contributor to the Intergovernmental Panel on Climate Change (IPCC), when he states that: “The three questions What is causing climate change? By how much is warming likely to accelerate? What level of warming is dangerous? — represent just three of a number of contested or uncertain areas of knowledge about climate change”

Aldus Emil Røyrvik.

Het rapport is omvangrijk. Het telt 82 pagina's en 61 voetnoten. Maar voor geïnteresseerden is het zeer de moeite van het lezen waard.

Het rapport is hier te vinden.

Voor mijn eerdere DDS-bijdragen, zie hier.