CO2 has been present in much higher concentrations in the atmosphere before just as it has been present in lower levels.

I asked one of the park employees there about it and he said the entire area across that part of LA seeps tar, the pits are just the most focused concentration of it.

Yun's accuracy on past predictions, as I live in San Diego, well, La Jolla, and I'm from DC/Potomac, and neither market would I list in the top 20 post-big-recession.DC has the BRAC [military base realignment concentrations from closing military bases] plus of course the government expansion to stabilize housing prices and rents -- but that means in a market correction, there was less loss of value and fewer foreclosures than national average -- so MANY other cities have far better cash flow numbers for multifamily properties than DC, for our market [b and c undervalued multifamily]So, I'll assume Mr.

WWII the US had "concentration camps" for Japanese Americans.

A change in the mix of buyers to more investors and concentrated ownership from those with money and income?

If you have got enough concentrated cash over the years, work and build use of it to serve the underlying purpose.

For now I am going to concentrate on fixing up all the high dollar items on my houses to weather the storm, and to pay down one or two of my lowest mortgages to reduce cash outlays in case I start getting vacancies. 

My hesitation with the higher priced & larger homes in Charlotte is you're concentrating your risk into one property.

if so I would be less concerned about the long term viability of gas.It might be a case where gas stations are a great investment but not really a good investment for your dad based on his age, concentration of risk with his investment portfolio and the number of current leases coming due in the next 5 years.Personally I think we will see a move to electric, but I also think we are on the verge of self driving vehicles. 

@Cody Nielsen  To answer your question about areas of Tahoe I like, the restrictions on STR's in the South Tahoe area (google Measure T Lake Tahoe) and just my personal preference kept me concentrated in the West & North shore areas.