14th February 2015 Megatons of plastic waste are entering the oceans each year Between 4.8 and 12.7 million metric tons of plastic entered the Earth's oceans in 2010 from people living within 50 km (31 mi) of a coastline, according to the results of a new study. Unless action is taken to improve recycling and waste disposal, the world faces an environmental crisis in the decades ahead.
A new study published yesterday in the journal Science provides another stark reminder of the impact that humans and their global civilisation are having on the world's oceans. Researchers from the University of Georgia looked at data from 192 countries with a coastline (i.e. not land-locked). They found that during 2010, these nations produced a total of 2.5 billion tons of waste. Of that, slightly over 10% or about 275 million metric tons was plastic. It is estimated that between 4.8 and 12.7 million metric tons — 1.7% to 4.6% — of plastic found its way into the oceans from two billion people within 50 km (31 mi) of a coast. Using eight million metric tons for a midpoint, "is the equivalent to finding five grocery bags full of plastic on every foot of coastline," says Jenna Jambeck, assistant professor of environmental engineering and the paper's lead author. "For the first time, we're estimating the amount of plastic that enters the oceans in a given year," said co-author Kara Lavender Law, research professor at the Massachusetts-based Sea Education Association. "Nobody has had a good sense of the size of that problem until now." If trends continue, Jambeck forecasts that the cumulative impact on the oceans will reach 155 million metric tons by 2025 – a year that is also predicted to see a crisis in landfill and urban waste, as well. This problem is likely to become even worse in the century ahead, based on World Bank calculations. On a business-as-usual scenario, the world is not predicted to achieve "peak waste" until at least 2100. These materials could remain in the biosphere until the year 2600 AD.
The plastic entering our oceans includes not only bags, bottles, six-pack rings and other packaging – but also microplastics, which are easy to swallow and therefore pose a danger to marine life of all sizes, from barnacles to whales. In addition, plastic pollution can serve as a carrier of invasive species and diseases, threatening native ecosystems. This ongoing disruption will contribute to many extinctions in the years and decades ahead. Up to 245,000 tons of plastic may be floating at the surface, according to Jambeck and her team – a figure that corroborates a similar study published in December 2014 that put the number at 269,000 tons, comprising a minimum of 5.2 trillion particles. Of particular concern is the North Pacific, where a swirling gyre of debris known as the Great Pacific garbage patch has accumulated, mostly consisting of plastic. Including four smaller gyres in other parts of the world, there is thought to be six times more plastic than zooplankton by dry weight. These impacts are not limited to wildlife, but affect human society as well. Plastics and their accompanying toxic chemicals in the food chain are known to contribute to cancer, malformation and impaired reproductive ability. Fishing vessels and other boats are damaged by marine debris, while beaches require cleaning up. In total, plastic pollution causes over $13 billion in damages worldwide each year.
The main culprits in this global problem are the emerging nations in Asia and Africa, which have rapidly growing economies, but have yet to implement sufficient regulations and waste management systems. By far the largest share of plastic waste originates from China, which contributes 3.5 million metric tons annually – compared to just 0.1 million for the US. After China, the next largest contributors are Indonesia (1.29m), the Philippines (0.75m), Vietnam (0.73) and Sri Lanka (0.64m). Plastic pollution in the ocean was first reported by the scientific literature in the early 1970s. In the 40 years since, there were no rigorous estimates of the amount and origin of plastic debris making its way into the marine environment, until Jambeck's current study. Part of the issue is that plastic is a relatively new problem coupled with a relatively new solution. Plastic first appeared on the consumer market in the 1930s and '40s. Waste management didn't start developing its current infrastructure in the US, Europe and parts of Asia until the mid-1970s. "It is incredible how far we have come in environmental engineering, advancing recycling and waste management systems to protect human health and the environment, in a relatively short amount of time," says Jambeck. "However – these protections are unfortunately not available equally throughout the world." One possible solution is the Ocean Cleanup Array designed by 21-year-old Boyan Slat. This concept would use a network of floating booms connected to processing stations that funnel plastic towards a central platform (attached to the booms) where a robotic system could sort plastic from plankton and store it for recycling. Following a year of research involving 100 volunteers and professionals, Slat's team announced the successful outcome of their feasibility study in June 2014. This is definitely a project to keep a close eye on.
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