An exquisite spring morning began, and I watched as the sun rose, shepherding a docile flock of clouds drifting in from the Gulf. Then a breeze picked up, a plastic grocery bag wafted over the fence and broke the spell. My world had once again been invaded by plastic.

Plastic is the ultimate imitation material, never quite as good, and somehow always a deception. I grew up with glass, leather, metal, and wood. Then came plastic everything. Blah. Plastic came in with World War II, over half a century ago.

It’s hard now to picture a world without plastic. But plastic in our lives is a trade-off between convenience and mountains of plastic trash. Our relationship with this material may be our greatest mistake. Plastics don’t biodegrade as we have been told.

Most plastics begin with two chemical elements: carbon and hydrogen, hydrocarbon. When the atoms link into long chains, the result is a polymer, from a Greek word meaning “having many parts.”

Polymers are nothing new. The silk spun by spiders is a polymer. Cotton and rubber are polymers. Your own fingernails are a polymer called collagen. But humans weren’t content with nature’s polymers and tweaked them.

In 1868, John Wesley Hyatt mixed camphor with a polymer called cellulose and got celluloid. He made billiard balls with it, and a lot of elephants owe him a debt of gratitude. Before Hyatt, billiard balls were made of ivory.

Vinyl arrived in1926. Teflon and Styrofoam arrived in 1938. Those and many other plastics like nylon were developed for use in World War II.

After the war, public consumption of polymers grew rapidly. Women bought “nylons” for the first time. But soon the downside of plastic became obvious. Life Magazine called us the “throwaway society,” citing our ubiquitous, overflowing landfills.

If you enjoy scary stories, try Alan Weisman’s scholarly “The World Without Us.” Chapter Nine, “Polymers Are Forever,” is especially chilling. But beware. There is no hiding place.

Never mind the landfills. Most plastics end in the world’s oceans, where they remain for eons. They don’t decompose.

Between Hawaii and California is an area in the Pacific that scientists call a gyre, where winds and ocean currents turn the sea like the slow circling of an unimaginably huge drain. The gyre collects all the floating plastic that comes down rivers into the sea, and keeps it forever. There were an estimated 3 million tons of plastic in an area the size of Texas, when it was first discovered in 1997. It’s growing; by 2005 it was 10 million square miles, nearly the size of Africa. And it’s only one of seven gyres on our planet.

In the half century since we started using plastics, an estimated more than a billion tons have been produced. “In India alone,” Weisman writes, “5,000 processing plants were producing plastic bags,” and Kenya, he continues, “was churning out 4,000 tons of bags a month.” When they are discarded, will they biodegrade? Yes, but too slowly to matter.

It gets worse. Polymers are natural magnets and sponges for persistent poisons like DDT and PCBs. When polymers disintegrate into dust-like particles, they remain polymers, which will be eaten by creatures as small as plankton, entering the food chain on an almost microscopic level, poisons and all. The BP oil spill is tame compared to that threat.

When we use plastic as though there is no tomorrow, it could be a self-fulfilling prophecy. Our tombstones might be made from a polymer resembling granite.