Can someone reading this blog who is plugged in to advising environmental organizations let them know that invoking hurricane impacts generally and Katrina specifically as reasons for greenhouse gas mitigation is not really helping their cause?

Comments like this from Environmental Defense, an organization with an impressive track record of environmental advocacy, often make me wonder if environmental groups are actually looking to give their opponents a justified basis for criticism:

Katrina tragically illustrated how vulnerable we all remain, even in the United States, to nature’s devastation. Moreover, given that New Orleans’ vulnerability to hurricanes had long been appreciated but never adequately addressed, it seriously calls into question the notion that we can simply adapt to the changes wrought by global warming. The costs from Katrina, still being tallied, are staggering, and the storm’s full cost—humanitarian, social, environmental and economic—will be felt for many years to come.

Katrina-like events will become more common and more widespread unless the emissions of global warming pollutants are capped. The link between global warming and hurricanes is yet another reason for Americans to insist on meaningful legislation to cap our greenhouse gas emissions.

To support this statement they cite papers from Emanuel, Webster, Holland, and Curry and disparage work of Klotzbach and Landsea. Here is what these six plus Anthes, Elsner, Knutson, and Mayfield had to say about policies related to hurricanes:

As the Atlantic hurricane season gets underway, the possible influence of climate change on hurricane activity is receiving renewed attention. While the debate on this issue is of considerable scientific and societal interest and concern, it should in no event detract from the main hurricane problem facing the United States: the ever-growing concentration of population and wealth in vulnerable coastal regions. These demographic trends are setting us up for rapidly increasing human and economic losses from hurricane disasters, especially in this era of heightened activity. Scores of scientists and engineers had warned of the threat to New Orleans long before climate change was seriously considered, and a Katrina-like storm or worse was (and is) inevitable even in a stable climate.

Rapidly escalating hurricane damage in recent decades owes much to government policies that serve to subsidize risk. State regulation of insurance is captive to political pressures that hold down premiums in risky coastal areas at the expense of higher premiums in less risky places. Federal flood insurance programs likewise undercharge property owners in vulnerable areas. Federal disaster policies, while providing obvious humanitarian benefits, also serve to promote risky behavior in the long run.

We are optimistic that continued research will eventually resolve much of the current controversy over the effect of climate change on hurricanes. But the more urgent problem of our lemming-like march to the sea requires immediate and sustained attention. We call upon leaders of government and industry to undertake a comprehensive evaluation of building practices, and insurance, land use, and disaster relief policies that currently serve to promote an ever-increasing vulnerability to hurricanes.

Question for Environmental Defense:

OK, I’ll bite. With the “meaningful legislation that caps greenhouse gas emissions” that you are calling for, what effect will this have on hurricane intensities and hurricane impacts over the next 100 years? Here is a hint (PDF) in formulating your answer. Readers feel free to answer as well.