*scratches head* Do you not live in the US, gritsar?
Biodiesel is perfectly legal in the US. We've got several distributors in MA. If you want to store more than a large-ish quantity, you need a permit for it, but around here something like >300 gallons can be stored before you need a permit. That's a lot of diesel to be storing. If you do want to store that much, you need a HAZWOPER license--requirements for that vary by state, it's usually a one-week course and $500. It's not a terribly difficult license to get, either, well mine wasn't. And then you need whatever town permits are required by your city. It costs less to get the HAZWOPER than to convert your car to biodiesel. There are also several
businesses who sell biodiesel manufacturing equipment for garage use. Again, you'll need to go through the permitting process, but it sure isn't illegal.
Ethanol goes stale? First I've heard of it...And I'm a biochemist by profession. It's probably not the best solution, only because our current distillation methods require more energy put into heating and fractionally distilling than we get back out of the combustion. It is tough on a regular gasoline engine, will make it burn hotter. But it gets only slightly less mileage; mileage is a function of engine efficiency/mass the engine has to work against, and the engine efficiency is affected by the normal heat of operation. Maybe you didn't realize, but Indy 500 racecars run exclusively on ethanol. Engines can be built to be EXTREMELY efficient on ethanol, it's a pretty simple engineering problem, certainly lots easier than re-designing a car to run on fuel cells or hydrogen.
Actually, I have talked in person with lots of people running biodiesel cars and veggie oil cars. They love their vegetarian cars! That's why my next car is going to be a biodiesel converted classic Mercedes-Benz--I just love that German engineering. Diesel and regular gas, in terms of emissions, are now about equal. Diesel used to be dirtier, but the newer ones don't have that problem.
Maybe electricity is generated by diesel generators where you live, flip, but around here our distributor gives us the choice between natural gas/coal/nuclear and renewables. You pay a bit more for using 100% renewable sources, but IMHO not painfully more--nothing that can't be mitigated by switching every household lightbulb to LEDs. I don't think anyone uses diesel generators for anything but emergencies, although I've heard of areas where there's pretty much no utility services and everyone has to have either a local municipal generator or be off-grid.
Interesting idea you have there about Greenland. Actually the cooling/warming phase and the Viking colony's demise are very well-documented for the layperson in Collapse by Jared Diamond. It was indeed green when they got there, but there were a lot more factors to the colony's demise than just some changing weather for a few decades: soil erosion from overgrazing animals, loss of contact with Denmark (they were not a self-sufficient colony and relied on trade with Europe), faulty economic decision-making by their rulers, lots of things made them susceptible to being wiped out by one additional disaster. The general consensus, supported by archaeological findings of the rubbish heaps, barns and houses, is that they starved to death while the neighboring Inuits were healthy and well-fed. It scares me more than a little to think that maybe we're not learning from their example--that we as a culture are so afraid of changes and unable to adapt to new situations, that we will either bicker over stuff while opportunities and time windows pass us by, or that we will refuse to change at all out of commitment to our lifestyles, even if that means dying for it.