How big is 7 billion?

Fascinating piece in this month’s National Geographic part of a new series dealing with the impact of 7 billion people on the Earth. Apart from the most obvious impact it discusses, such as by building cities—essentially vast stretches of man-made materials—it also discusses the concept of “Anthropocene” —The Age of Man. A proposed new name for a new geologic epoch defined by our impact on the planet that will endure in the geologic record long after our cities have crumbled.

From a geologic perspective however, the most plainly visible human effects on the landscape today, like cities, may be the most transient.

“Probably the most significant change, from a geologic perspective, is one that’s invisible to us—the change in the composition of the atmosphere. Carbon dioxide emissions are colorless, odorless, and in an immediate sense, harmless. But their warming effects could easily push global temperatures to levels that have not been seen for millions of years.”

Combine the two and you get the eerie, other-worldly city pictured above—Dubai. Oil transformed Dubai in the 1970’s. The city now boasts the world’s tallest building and 2 million inhabitants who depend on desalinated seawater and, ironically, air-conditioning—and thus on cheap energy—to live in the desert. Air-conditioning the desert of the present to (probably) create the desert of the future.

The other fascinating feature is just how big 7 billion actually is!

♦ ½ the age of the Universe in years

♦ 2 and one fifth centuries to count it aloud at 1 number per second

♦ 30 hours’ worth of text messages sent in the US

♦ 133 times around the Earth if taken as steps

Makes you wonder how our National Debt figures would stack up!