about a decade ago, purchased a home half a mile away from a river. For the last 50 years, the river bank has been has been slowly moving outwards out due to erosion. I bought the house for a million, it's now worth two.

Last year, a thousand houses a few miles downstream fell into the water. This year, my insurance company cancelled my coverage, and I can't find anyone else who will insure me. What I'd like is for premiums to be raised for people who bought their homes in a safe area, to pay me my million dollars in profit when my house falls into the watter. This is my Current home. Am I supposed to just abandon it because no one will buy it?

So, the answer to your question, is yes. Home prices go up and down. Yours is now worth zero because of your bad decision. It is not the job of other people, to pay you for your mistake.