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.