What is the most important engineering problem of our future?

[Kevin Sevcik]

I'll toss my vote in for oil. It's bigger and more immediate than any piddling social problems. Deal with social problems after you've ensured an alternative supply for energy and food. Yes food. In addition to all the other petroleum based products listed above, did you know your cheap abundant food is petroleum based as well? The vast majority of fetrilizers are petro based, and most all food requires a good deal of fertilizer.

Really, though, the largest use of oil is for energy. Especially for transportation. Atleast 75% of oil goes into planes, trains, and automobiles, as it were. Come up with a cheap, efficient alternative for energy, and the oil supply will easily cover all other uses for several decades.

As for alternative energy sources, Solar Towers look promising.