One of the most awesome monuments of the ancient world still around today is the Great Pyramid of Giza, but one study shows that the modern world is unwittingly producing a lasting plastic monument that could rival nearly 2,000 of those in less than two generations.

At current rates, about 12 billion metric tons of plastics will make it into the world’s landfills by 2050, and that’s not counting those that will be recycled or incinerated, according to a recent study by the American Association for the Advancement of Science.

The Great Pyramid of Giza weighs about 6.5 million tons, so the amount of waste plastic expected to be put into landfills by 2050 would weigh as much as 1,846 Great Giza pyramids. Given that the stone in the Giza pyramid is about three times more dense than most plastics, those plastic pyramids would be much more massive in size.

Plastic expected to make it into landfills by 2050 alone dwarfs the amount of plastic ever produced since the 1950s, when large-scale production of plastics began, the study noted. Since the 1950s, about 8.3 billion tons of plastic have been produced, with about 6.3 billion tons of that being discarded. Of that discarded plastic, only 9% has been recycled, 12% incinerated, and the remaining 79% going to landfills.

The explosion in plastic production has happened only recently, however. Of the 7.8 billion tons of resins and fibers that go into making plastic produced since the 1950s, half, or 3.9 billion tons, has been produced just in the past 13 years, the study said. Much of that rise has been driven by the packaging market. And the global shift from reusable to single-use containers has resulted in a jump in throwaway plastic.

“As a result, the share of plastics in municipal solid waste (by mass) increased from less than 1% in 1960 to more than 10% by 2005 in middle- and high-income countries,” the study noted.

While the U.S. led the rise in the plastics industry since its inception, China has become a major player, now accounting for 28% of global resin production and 68% of global plastic fiber production, the study noted.

The global plastics market is expected to reach $654.38 billion by 2020, driven by packaging, construction and automotive demands in emerging markets like China, India and Brazil, according to San Francisco-based market research firm Grand View Research.