Monday, March 31, 2014

From Projected Impacts to Risks and Adaptation

The two word clouds above show the relative importance of different words in the recent assessment report of Working group 2 compared to the previous report (AR5 v AR4, Summary for Policy Makers document). Much emphasis has been given to the concept of 'risk' in AR5 (top) which was not the case previously with AR4 (bottom). The AR5-WG2-SPM mentions 'risk' 70 times in all 44 pages, and today's press release uses the word 22 times on its 2 page statement.

However, the switch to the risk language is not unproblematic. Risk involves decisions and suggests there can be an objective assessment of risks with attendant risk management. This is a different concept to uncertainty, where we do not know the odds to calculate risks.

Working Group 2 is supposed to take into account the main findings of WG1. It is therefore logical to assess future impacts of, say, a 2 degrees temperature rise on natural systems, and on different sectors of society.

The take on adaptation and decisions to reduce vulnerability is therefore well taken. However, the shift from 'projected impacts' to 'risks' runs the danger of suggesting we could know how climate change will play out and it would be merely a decision to perform the right kind of risk management. There seems to be also a tension in the narrative between climate impacts which are already visible and those yet to come, which are still worse. At this point reference is made to the man-made character of the impacts, and the importance of mitigation, topics which are, strictly speaking, outside WG2's remit. It does not matter where the changes come from if things change for the worse. If preparation for future hazards is possible it should be done, no matter what the causes. And how much mitigation can be achieved is a matter of political struggle and technological solutions.

Today's media reactions partly suggest that the WG2 report is used as a tool for exhortation in terms of mitigation, despite all the efforts on part of the panel to avoid blatant alarmism. It is too early to assess the impact of this new risk language. But it seems as if the climate narrative is heading towards a branching point: some consumers of the report expect more drama with every new report and are interpreting this latest instalment in this vein, too. Others think that a more pragmatic and less scare mongering approach has taken root, partly in reaction to the criticism about the previous report. Maybe both are right, but this would stretch the interpretative flexibility of the IPCC considerably.


Anonymous said...

Isn't this report about risk?

@ReinerGrundmann said...


the report of WG2 is called "Climate Change 2014:Impacts, Adaptation, and Vulnerability"

@ReinerGrundmann said...

The communication of climate science is an interesting enterprise. We have sum total of published research, of which (some? most?) is evaluated by the IPCC. The IPCC then produces a long report, in three parts, plus a synthesis report.

It also publishes Summaries for Policy Makers and Press releases, and supportive material in multimedia formats. The media, politicians, and interested groups and individuals then take up elements from this bulk of material. They select, interpret, and play up or tone down specific aspects or claims. Scientists also enter this debate, both from the inside (as IPCC-authors in various levels of responsibility) and from outside, either in support of the IPCC or critical of some aspects.

It is not surprising then, that despite claims about an alleged consensus there is, at times, the impression that we are listening to a cacophony. Attempts at 'correcting' 'misrepresentations' of 'the science' are usually invoking the IPCC report, but this is not a monolithic text.

What can one do to forestall such communication problems? You produce a list of frequently asked questions (FAQs). This has now been done with regard to the WG2 report. The question is: does it add another layer of complexity by selecting specific questions and spinning the answers, or is it really helpful in clarifying confusion/inconsistencies where they may exist?

Here is the WG2 FAQ, 'largely hidden from view deep on the ipcc website' (Revkin)

H/T Nico Stehr & Andy Revkin

Anonymous said...

I know what it's 'called'. I was talking about what it's 'about'.

@ReinerGrundmann said...

There is indeed an interesting tension in the argument as the IPCC WG2 adopts a new framing, the framing in terms of risk, not uncertainty. Risk is manageable, and rests on knowledge of probabilities and size of damage. It appears that the size of potential costs has been lowered compared to the previous report but we still have incomplete knowledge of probabilities. In some cases there is 'high confidence' expressed (for example on p.12 of the report which lists 8 'key risks'), in other instances the language of uncertainty is still present, for example under the headline The Decision-making context:

'Responding to climate-related risks involves decision-making in a changing world, with
continuing uncertainty about the severity and timing of climate-change impacts and with
limits to the effectiveness of adaptation.'

Sometimes both frameworks are applied in a single sentence which leads to confusion:

'The precise levels of climate change sufficient to trigger tipping points (thresholds for abrupt and irreversible change) remain uncertain, but the risk associated with crossing multiple tipping points in the earth system or in interlinked human and natural systems increases with rising temperature (medium confidence).'

In this example the word risk is used as a synonym for probability, but the statement is presented as one of medium confidence only, which means that even the postulated link between the probability of crossing multiple tipping points as a result of rising temperature is not widely accepted by the panel.

Pekka Pirilä said...

The second excerpt from WG2 represents the worst part of the way IPCC reports present uncertainties.

I would say that it's trivially true that the probability of crossing multiple tipping points increases with temperature, but the significance of this increase is not known at all. It probability may remain low enough to be ignored or not. When crossing even one tipping point is so certain, how could we know anything more on multiple.