From stone age to plastic age: pollution in the fossil record gives the name of scientists to the modern era

Plastic pollution is now in the fossil record – a discovery that could mean that this period of time is becoming known as the age of plastic, say scientists.

Plastic deposits have increased exponentially since the end of the Second World War and have doubled about every 15 years, researchers said after combing two hundred years of sediment in the Santa Barbara Basin in California.

"We all learn at school about the age of stone, bronze and iron – will this age be known?" Asked senior author Jennifer Brandon of the Scripps Institution of Oceanography at the University of California at San Diego. "It's a scary thing that's why our generations will remember us."

Most plastics were invented in the 1920s, but it was only after World War II that they were used extensively. Scientists found microplastics – most of them textile fibers – in reasonable quantities in all layers of the core after 1945.

"Our love of plastic is actually left in our fossil record," said Dr. Brandon. The Guardian. "This study shows that our plastic production is almost perfectly copied into our sedimentary record."

Scientists have discovered that in 2010, people deposited 10 times more plastic in the basin than before the Second World War. The post-war era also showed an increase in the diversity of plastics – including plastic bag materials, plastic particles as well as fibers.

The study, published in Progress of science, is the first to watch the accumulation of plastic in one place. The researchers chose to study the Santa Barbara Basin because the waters are always calm and there is an almost total absence of oxygen, which helps to preserve the sedimentary layers.

Each 5 mm sediment corresponds to two years of history and scientists were able to sample sediments dating back to 1843.

Previous research conducted by Scripps has revealed the presence of microplastics at depths up to 1,000 m (3,300 feet) off Monterey, California. In April, an explorer visited the Marianas Trench in the Western Pacific Ocean – the deepest natural trench in the world – and discovered plastic bags.

Scientists estimate that between 4.8 and 12.7 million tons of plastic waste enter the ocean each year.

"Our results show that such an increase is now detectable not only in the surface waters of the oceans but also in a benthic ecosystem. [the lowest level of a body of water], as recorded in the sedimentary record, "the researchers wrote in the paper.

Scientists say that they "predict that this increasing rate of plastic deposition will continue to increase in the future, unless there are noticeable changes in policy or waste management."

Earlier this year, scientists from the Marine Biological Association and the University of Plymouth discovered a "significant increase" in the largest plastic items found in the ocean from 1957 to 2016.

Among the plastic objects recovered in the oceans, such as bags, ropes and nets. This waste already causes more than 10 billion pounds of economic damage every year to marine systems.

If these trends continue, marine plastics are expected to overtake fish by 2050.