[kbutler]

How much would you spend (or spend to convince the government to spend) to keep your billions-of-dollars-worth-of-real-estate viable?

Building sea walls is a trivial cost compared to moving (and giving up the real estate to the sea). Ask the Netherlands - 26% of the country is below sea level - up to (or down to) 6.7m below.

[davedx]

The Deltaworks project did not have a trivial cost, and the Ministry of Water in the Netherlands is deeply concerned about how we will mitigate further sea level and river level rises.

[kbutler]

"Altogether the Delta Works cost nearly 5 billion Euros." http://www.deltawerken.com/The-Delta-Works/1524.html

"The South Holland coast region is home to approximately 4 million people who live below normal sea level" https://www.ice.org.uk/what-is-civil-engineering/what-do-civ...

Roughly 1300 Euros per person protected. How much would it cost to move those people? And what is the total value of the real estate where they live/work/farm?

So yes, "Building sea walls is a trivial cost compared to moving (and giving up the real estate to the sea)."