I'm with JKenny, the biggest problem is the expansion of our population as a race. "Go Forth And Multiply!" That's what the human population has successfully been doing for thousands and thousands of years, expanding, exploring, migrating, conquering, utilizing, evolving, civilizing, industrializing, and now, destroying the very land upon which we live. Resources are being used, and not just fossil fuels, if we continue to expand as we are doing there simply won't be enough food for us to survive. Throughout history, most wars have had trade and resources at their core (leading to ideological battles) fueled by imperialistic motives. The fewer the resources, the higher the demand.