What's the dif? Uncertainty versus risk
Uncertainty is about what we don't know yet, while risk is about what we could lose.
There's both in climate change.
I gather that politicians and other public figures don't like to admit we face risks so they use 'uncertainty' as a euphemism for risk. And if the public figures admit there are risks, they like to talk about the risks as existing somewhere in the future.
I get it that, "one may have uncertainty without risk but not risk without uncertainty," as we can be uncertain about something like what our colleagues will wear to work, yet that comes with low to no risk of a negative consequence to ourselves. We can be uncertain about when our children will finish potty-training, although as one wag put it, "They usually figure it out before college."
So an uncertainty can slip into certainty with the passage of time; everyone dies sooner or later. But is death a risk if it is inevitable? Perhaps determining the risk of death is better confined to consideration of loss. If someone dies "before their time,"what ever that is, it is a loss.
On a lighter note, my daughter's cats will almost certainly jump on the kitchen table, which puts the tablecloth and glassware at risk of damage. The only uncertainties left are when and how much damage.
Yesterday evening's presidential debate included a comment by Mitt Romney on the future of the U.S. military. He rationalized increased military spending saying, "So we have to make decisions based upon uncertainty. And that means a strong military."
I think the current military keep track of the difference between uncertainty and risk. The decisions they make are based on risk assessment. They need the intelligence gathering to detect danger, and mobilize, not be stuck with fixed assets in the wrong place.
A good strategy to minimize risk is alert observation and flexible response. In contrast, if risks are already known, then prioritize responses and commit more assets one way or the other.
With climate change, the risks (future negative impacts) are becoming clearer, while the residual uncertainty about when exactly those negative impacts might befall or how moderate or extreme they might be, seems to be the refuge of those who don't want a strategy that admits that the risks and unknowns both exist. Yet it is just as foolish to think of climate change as a known and limited risk with a single solution. Dave Roberts at Grist points to the example of Ho Chi Minh City that built barriers to keep out the rising sea only to discover that revised estimates of sea level rise mean that the ocean will over-top the barriers.