(Source: AutoblogGreen; Photo: Jalopnik)

Take a walk through any junkyard in the world and you’re likely to come across any number of vehicles that are a mere rusted-out shell of their former selves. That’s mostly because sheet metal is thin and, as the outer-most skin of an automobile, takes the brunt of the weather’s nastiest beatings. Underneath, it’s a different story entirely.

Photo: Netwind.ru via Jalopnik

An article on AOL Autos examines the major bits and pieces of an automobile and offers rough estimates of how long it takes for the average vehicle to rot away, and there are a few surprises.

• Rubber tires decompose naturally over a fairly reasonable-sounding period of 50 to 80 years.
• Engine blocks will take at least 500 years to break down.
• And finally, the windshields take more than a million years.  That’s the figure that the figure that the U.S. Park Service uses for glass objects, and some experts in waste management think that is an understatement. Theoretically, glass lasts forever, and it would take eons of geological action to grind it into anything resembling the sand, or silica, that it comes from.

Fortunately, nearly every bit of modern automobiles is recyclable, and automakers have been making serious advancements to bring that figure as close to 100 percent as possible. USCAR says that about 95 percent of vehicles go through the end-of-life recycling process. Still, AOL Auto’s sobering figures should serve to remind us how important it is to properly dispose of used-up vehicular machinery, especially with the advent of government-sponsored scrapping programs.