Sea level rise and New Orleans?

Question

How much sea level rise would it take to flood a significant portion of Mew Orleans? Is it plausible? If so what time of time frame would this happen in?

Answer 1

A direct answer is that New Orleans itself would be little affected by a rapid rise in sea level of even several feet.  A by-product of the levee system (built for hurricane protection) is the city is basically surrounded by earthworks similar to those used by the Dutch to claim land from the sea.

However, a rise in the sea level of several feet would submerge much of southeast Louisiana (the parts outside the levee system) and that would have negative ecological and practical effects on New Orleans.  

Note that sea level change is both a scientific and a political issue, with non-scientist "activists" getting most of the media attention.

Sea level has been very stable for thousands of years, and is now much higher than it was during the last ice age. It appears sea level has been rising slowly (1 to 2mm per year) for the last 6000 years.  There are claims sea level rise has accelerated in the past 100 years or so, by about an additional 1mm per year,.  The satellite information that produced the data may be correct, may be measuring a "blip", or the pre-satellite data may have been interpreted incorrectly.

Predictions regarding sea level in the future vary wildly from 110mm over the next 100 years (same rate as over the past 6000 years or even a bit less) to 770mm over the next 100 years.  Note that a meter has 1000mm, so the most aggressive prediction if for a sea level rise of 2 more feet by the year 2100.  Also note that the amount of water required to raise the level of the oceans by 2 feet is staggering, and can actually only come from volume expansion due to warmer water. Melting all of the ice o the planet won't do it.

Note that sea level rise is not guaranteed. A cooling of the earth (which is a widely-held scientific prediction that doesn't get much attention from the media) would drop sea levels - like only 6000 years ago (less than a blink of the eye in geologic terms)