That sounds about right to this lay observer.

I like the dice analogy as a way of explaining this sort of causality.

The gift of explaining scientific concepts clearly will be increasingly valued in the coming years. I hope you write more for Gristmill!

>> I think it's likely to stay that way  >>

No precautionary policy ?
Just wait and see.. ?

What a wonderful frame of mind, I suppose you don't live near the Gulf.

But even if you live inland, there will be an increase in tornado activity.

It seems china bore a lot of wind activity with its typhoons.

Good Luck.

I think you misunderstood what I'm trying to say.  What I mean is that it's unlikely our scientific knowledge will ever be able to determine what fraction of Katrina's (or Rita's) intensity to attribute to global warming. This doesn't tell us anything about what policy we should adopt, e.g., should accept significant risk or adopt the precautionary principle, etc.?  As you can tell from my post yesterday, I'm a firm believer in heading off risks before they materialize.

Regards

PS: I do, in fact, live near the Gulf.  

I've heard this dice analogy before. What it says is that it's a question of probability, the parameters of which are handed down to us by experts, who have this or that climatology degree, wear sciencey-looking white coats, yadda yadda yadda.

So you can never say climate change caused any severe storms. But doesn't this open the way for some absurdity at some point in the future? Let's say we get to the point where the dice are loaded to the point where only one face of the die means that climate change didn't cause a storm's severity. At what point do we release ourselves from saying "we don't know?" Perhaps not until it's too late for the persuasiveness of our certainty to have any impact on the problem.

I think Gore's movie was on the right track when he gave people an idea of the mechanism that creates the severe storms. He showed Katrina moving over the warm water and talked about how climate change means more frequent, unusually warm water. I think this is the better way to go. We can say something like climate change produces patches of progressively longer-lasting, warmer waters, creating more windows of opportunity for severe storms. Climate change creates more vulnerability for bad storms hitting our coasts. Something like that. Maybe someone can say this clearer than me.

I remember Roger Pielke saying that a bigger problem than CO2-enhanced storms ,is that too many people live on the coasts, and that more people move there every day, and that this creates more risk than climate change does. This may be true, but this doesn't take some things into account:

One-- people who choose to live on the coast bargain that they'll get natural hurricanes, but they might feel differently about human-enhanced hurricanes (and some people in third world countries that live on the coast didn't even produce much of the CO2 that caused the problem).

And Two-- stronger hurricanes are a major data point on the public's radar that we are changing the world. If we're creating stronger hurricanes, we can only guess what other problems we are creating.

So anyway, I don't think hurricanes, or even Katrina should be dismissed as part of the climate change discussion...

jjwfmme-

Here's my answer to your question: At what point do we release ourselves from saying "we don't know?"

When we get enough good statistics that show that hurricanes are getting stronger.  In your example, if six were loaded to come up 80% of the time on a six-sided die, it would only take a few rolls to determine that.  If the loading were slight, then it would take many more rolls.  Regardless of the loading, at some point we can look at the data and say that the die has changed.  

Even at that point, however, we still wouldn't be able to say with great confidence whether a single roll (storm) was caused by loading the die (global warming).

Regards

... that there are many, many other areas of our lives where we take statistical risks seriously, despite our inability to trace the exact cause of any single incident. It is, for instance, impossible to say that a given case of lung cancer is caused by cigarettes.

There are also plenty of places where we act to address risks we are unable to exactly quantify. What was the statistical chance that Saddam would develop WMD and hand them off to terrorists? Impossible to say, particularly with the state of our intelligence, but the very same people who deride the notion of counteracting global warming happily signed on for a massive expenditure of resources to head off that faint risk.

It's important to understand our state of knowledge around hurricanes and global warming, but it's also important to note, given how arbitrarily standards of proof and evidence are applied to various kinds of risks, that there must be something else going on here besides pure risk assessment. What that something else is -- what makes people so resistant to the idea of addressing global warming -- is a mystery to me, I confess.

www.grist.org

  Dear David,

     It's the fear of change.  Most people fear and resist change (there are personality types that seek change, but they are in the minority).

     Most people change only when they feel they must.  They don't have this feeling about global warming yet.

patrick