The response to my article in the Wednesday paper on rising sea levels suggests a strong public hunger for more information about the risk. People have been e-mailing us with questions, so let me offer a few more details.

The first thing to point out is how little effort there seems to be on the part of governments to inform people of the risks that Americans are running along their coasts. Orrin H. Pilkey of Duke University, the reigning dean of American coastal studies, called my attention to a battle he is waging in North Carolina about informing the public there.

The Bush administration famously refused to publish parts of a study about sea-level rise conducted by the federal Environmental Protection Agency, and the principal author, James G. Titus, went outside channels to set up a Web site that provides some information.

The political reluctance is certainly predictable — telling people about a long-term existential threat like this is just not a job that your average politician, elected for a term of a few years, may want to tackle. For that matter, it’s a hard subject for the rest of us to think about intelligently.

Although the risk of coastal flooding is slowly worsening year by year, it’s true that the worst consequences of sea-level rise, if they ever materialize, are still a long way off. Most people simply have trouble contemplating risks to their great-grandchildren. We’re a lot more interested in our own skins!

(As proof, I will tell you that two Times editors came by my desk this morning wondering about the near-term risks to their homes in low-lying areas of Long Island.)

For a more in-depth Times article on sea level rise, see the long piece I reported from Greenland in 2010. Additionally, I would commend to all interested readers the two scientific papers that are the basis of the Wednesday article. The journal Environmental Research Letters has made the full text of both accessible to the public.

The main paper calculates the size of the population at risk in the lowest-lying coastal areas, producing the national figure I used of 3.7 million; the paper itself gives detailed breakdowns by state.

“Much has been made of the threat that sea-level rise poses to heavily populated low-lying nations and island states,” Matthew England, a leading climate researcher at the University of New South Wales in Australia who was not involved in the study, wrote by e-mail. “This study demonstrates that the U.S. is also highly vulnerable to the impacts of sea-level rise, with potentially massive costs in adaptation if carbon dioxide emissions continue to grow unabated.”

The second paper weighs the risk that severe storm surges will become more frequent over time as a consequence of rising seas. The issue is not just the risk to property right on the ocean. With a higher sea, inland flooding becomes more likely, too, given that the rainfall from a heavy storm is likely to take longer to drain through rivers and estuaries.

Interestingly, some of the biggest impacts of this storm-surge risk are likely to come not where you might expect, say, the Gulf Coast, but rather in California. Coastal flooding is so rare there that low-lying areas like parts of Huntington Beach and Long Beach appear to be highly vulnerable even to modest sea-level rise.

Let me note, though, that the California government is more aggressively on the case of climate change than any other state, backed up by the voters themselves.

The Web site of Climate Central, where these sea-level studies were mainly done, has a great deal more useful information, including the ability to search by ZIP code and get a sense of your own risk. At times on Wednesday the Climate Central computer servers were overloaded, so if you have trouble getting the search to work, try again a while later.

Many people are probably wondering who out there might be advocating coastal policies that make sense in light of the future risk. Is a coherent program on offer anywhere?

Most coastal scientists I know have never advocated radical measures like forcing people to move away from beaches. They do advocate greater limits on coastal development, especially when it comes to high-density buildings.

Perhaps their single strongest recommendation is to start pricing flood insurance, sold mainly by the National Flood Insurance Program and backstopped by federal taxpayers, at levels that reflect the true risk of coastal storms and incorporate the likelihood of future sea-level rise.

That by itself, one imagines, would cut down on oceanfront construction, since it would raise the running costs of owning coastal property. An interesting left-right coalition is pushing just such a package of measures in Congress.

The coalition includes environmentalists who want to limit coastal building and libertarian groups that want the government to stop using taxpayer money to subsidize it. With the National Flood Insurance Program in serious financial trouble after Hurricane Katrina and other recent disasters, the chances that this group might get something through Congress would seem to be greater than zero.

(Source: www.nytimes.com )