Are marine and coral scientists too reticent?

'Reticent' is just about the last word I'd associate with most of the scientists I have been privileged to talk to. But, like the joke about the economist asked how his wife was, compared to what (or who)?

The matter comes to mind with the re-publication this week, under the title Huge Sea Level Rises Are Coming Unless We Act Now, of an article by James Hansen that has been going around in various ways since March (see, for example, here) and/or May (Scientific reticence and sea level rise). Hansen argues that some scientists have been excessively cautious, and advances a more alarming scenario about sea level rise than, for example, Stefan Ramstorf at RealClimate.

Back in April I blogged about the relatively rosey (reticent?) forecasts for coral reefs in the final draft of the IPCC Fourth Assessment Report Summary for Policy Makers (SPM). This said that coral [reefs] might be able to cope with a temperature rise of up to 3°C in a few decades, whereas the scientific consensus was that the actual threshold (OK, set of multiple thresholds interacting with other factors) is likely to be significantly lower.

It looked to me like a case of excessive reticence. But the feeling at the time seemed to be that even if the headline was not as scarey as many people thought it should be, the Report itself made the likely gravity of the situation clear enough...if you could be bothered with the details. As our man Simon Donner restates in the comments section at the foot of his most recent post:

I could forgive the loose wording in the SPM if it were not for the 3°C limit. I was one of the reviewers of the coral reef sections of the WGII report, from which the SPM was drawn, and I don't recall any specific mention of 3°C, nor any literature sources to specifically support it.

Nevertheless, as I've argued before, rather than get caught up in the geopolitics of the IPCC summary for policymakers, we should celebrate the fact that the full reports have cobbled together and thoroughly reviewed all the science on these issues. I don't think governments could effectively use this bit of SPM language to "promote" a different agenda, because there are too many people watching, and ready to hold their government's feet to the fire.

To which my first reaction is, good points. I hope you're right.

But my second reaction is, well some guys play with hard balls (and, indeed, bats), and the SPM opens a door for those who would push a general idea of "corals could be fine with a 3°C rise" that is not atuned to what the science actually indicates, whatever the consensus and/or debate within the scientific community itself and the best efforts of conservationists and some other enlightened actors.

Perhaps I worry unduly. In any case, if sea level goes up by 5 or 6 metres in a hundred years even fewer people will spend their time thinking about coral reefs. And ocean acidification could do for them next century if not this one. It is indeed all relative.