his is a terrific book. Weisman presents a hypothetical situation: suppose all
humans on the earth suddenly vanished - due to plague, the rapture, or some other phenomena, but the rest of the
earth was left intact, just as it stands today. Weisman asks: how long would it take for the earth to recover
from the abuses inflicted upon by humanity? The answer: not very long.
Weisman proceeds to show us in each chapter what happens to the creations of humanity.
For example, the typical American home might survive 100 years without maintenance, before it disappears into
the encroaching vegetation. The biggest enemies are wind and rain. Once the windows break or the roof leaks, and
moisture enters the structure, the wood quickly rots. Insects chew on the lumber. The metal joints/bolts/nails
that hold everything together begin to rust and deteriorate - and before too long a storm causes the whole building
to collapse. Not much remains except bricks from the fireplace and the concrete foundation, which vanish under the
returning natural vegetation.
On a larger scale, Weisman describes the downfall of an unmaintained New York City. The causes
of the collapse are the same culprits: wind and especially water. Beneath Manhattan are huge volumes of water. It seems
that much of the city is built over ancient rivers and swamps that were filled in to make valuable real estate. So much of
the land of Manhattan Island is wetland in its natural state. The subways
of New York are in constant need of pumping today just to stay dry. Indeed, if the power outages from the 9-11 attack had lasted longer,
some of the subway tunnels might have flooded. Of course, with global warming increasing the average level of sea level,
Manhattan has some challenges in its future, even if all of humanity doesn't disappear suddenly. Once the foundations of
the skyscrapers are flooded with water, they won't stand for long.
In one chapter, Weisman takes us to the Demilitarized Zone between North and South Korea. It is a
stretch of landscape a few miles wide that extends entirely across the Korean Penisula. Since it is heavily mined and guarded,
humans must stay out of the area, which has allowed it to revert to it's natural wild state. Thus, it has returned to a heavily
forested area supporting rare species of deer and leopard. (I can't help but wonder - why don't these animals get blown up by the
mines? If no one knows where the mines are, how do they maintain/replace them? Certainly no mine is reliable after 50 years!)
50 years is not a long time, but it is enough for almost all traces of humanity to disappear. It demonstrates just how ephemeral
our species is upon the planet (not to say that we don't have an impact, in fact, humans are having a gigantic impact on the
environment, but Weisman's point is that if we could magically stop destroying the land around us, within a few short generations
our ancestors could enjoy an Eden like planet. Ultimately, I think this book is trying to deliver a hopeful message.)
Of course, some signs of humanity will last much longer. Already the Great Pyramids have survived 4 thousand
years. Weisman guesses that the faces on Mount Rushmore could last hundreds of centuries. There are some cities carved into the
rock of Turkey that are so ancient we don't even know their true age - in their dry, sheltered environment, they could last a long
time into the future. And, unfortunately, plastics also will survive for quite along time too. Plastics don't degrade. They get
broken apart into smaller fragments, but the plastic dust does not dissolve. Out in the Pacific Ocean there now exists a gigantic
swirling, ever-growing trash heap of plastic pollution and other refuse that floats over the ocean.
Every chapter is interesting. Domestic cats will turn feral and survive, but dogs are not fierce enough to compete with the
predators that would return. Cockroaches need the heat of our buildings to survive - so they would have a big dieback if humans disappeared
(Funny that you always hear that after a nuclear war the only survivors would be rats and cockroaches, but apparently cockroaches are not
so resilient after all.)
This book is quite interesting. It is a fast read, and it has lots of material for conversations.