How is this statement at all helpful to anyone making policy decisions?

1) You don’t say whether the warm SST years will become more prevalent, or how much warmer they will be, and

2) You don’t quantify what “greater annual loss” actually means.

Roger Pielke Jr.’s data indicate an average annual adjusted loss of $13.5 billion from 1950 to 2006.

If ALL years were to increase in SST by, for example, 2 degrees Celsius, what would the quantitative impact be? Would average annual losses go from $13.5 billion to $13.6 billion? Or $136 billion? Or some number in between (and if so, what number)?

Aren’t those quantitative answers important?

Yes, let’s (and by “us,” I mean someone who has more time and cares more than I!) obtain the normalized losses and SSTs on a per-event basis, and run that regression.

Enquiring minds want to know what will happen. (But this enquiring mind doesn’t want to know enough to bother actually trying to get per-event data and coincident SSTs.)

I still haven’t made up my mind yet …

Moving from below average to above average SSTs, how can we be sure we are not just watching a diminishing influence of the well-known SST temperature treshold for hurricane genesis? Once that treshold is definitely exceeded, there might be no furter increase in losses.

Subject to that predictions might be correct if SSTs are not far from medium temperature range but fail completely in the high SST range – predicting even higher losses when actually they are rather stable …?

One question at last: Is it possible to obtain normalized losses and SSTs on a per-event basis?

Sure. In your paper you write:

“Using the preseason Atlantic SST, we are able to explain 13% of the variation in the logarithm of loss values exceeding $100 mn using an ordinary least squares regression model. The relationship is positive indicating that warmer Atlantic SSTs are associated with larger losses as expected. The rank correlation between the amount of loss (exceeding $100 mn) and the May-June Atlantic SST is +0.31 (P-value = 0.0086) over all years in the dataset and is +0.37 (P-value = 0.0267) over the shorter 1950–2005 period.”

You find an r^2 of 0.13. I characterize this as less than 0.10 because of the overwhelming influence of 2005 (hence “<10% variance level”).

“not particualrly strong stuff” means that given these relationships, both that you assert in your paper and that I replicated, I don’t find your stated 60-70% confidence that future increases in SSTs will be accompanied by increases in damage to be a very strong statement.

I know that you disagree. Fair enough.

Thanks. From here on I’ll choose to emphasize the areas where we are apparently in closer agreement with respect to the focus of my original post.

So I’ll repeat my earlier conclusion:

Taking all of your assertions at face value, I’d characterize your 60%-70% probability of a future SST-damage relationship at the <10% variance level as not particularly strong stuff. Knowing far less than you do about hurricanes-climate, I’d put my personal probability at closer to 50%. So we are really not so far off in our views, no matter how aggressively they are presented!

Nope…my paper is perfectly consistent with my assertion. The correlation between tropical SST and NAO is small. So a future where warm SSTs are consistently accompanied by recurving hurricanes, while possible, is inconsistent with the historical record.

Best,
Jim

Thanks. Your personal probability may indeed be correct, seems completely logical to me. But your paper (Jagger et al.) doesn’t support this assertion (e.g., what if warmer SSTs are routinely accompanied by an unfavorable NAO?) — nor does any other analysis of the historical record that I am aware of.

But taking your assertion at face value, I’d characterize a 60%-70% probability of a relationship at the 10% variance level as not particularly strong stuff. Knowing far less than you do about hurricanes-climate, I’d put my personal probability at closer to 50%. So we are really not so far off in our views.

Thanks!

On your narrow question I would still respectfully disagree with you. If all we know are SST and damages from history, then I would assign a personal probability of 60-70% that over the next 100 years the warm SST years will, on average, have greater annual loss totals compared to the cold SST years.

Best,
Jim