Spoil heaps, landfill sites, incinerators and scrapyards of the world are bursting with a tide of e-waste, a discarded and growing sea of computers, cellphones and household appliances, according to a new international survey.

In 2019 businesses, industries and households threw away nearly 54 million tonnes of electronic waste: that is, devices – from computers and cellphones to refrigerators and vacuum cleaners – that need a power plug or a battery. And this detritus included an estimated US$57bn in gold, silver, copper, platinum and other expensive metals.

Less than 18% of this costly material went for recycling. In a separate study, Irish scientists have found that much of the plastic waste collected in Europe and exported for recycling ends up in the oceans: in 2017 the burden of polyethylene tipped into the seas off south-east Asia could have totalled more than 180,000 tonnes.

Discarded electronic gear – e-waste – is now the world’s fastest-growing waste stream, according to the latest report from a UN monitoring consortium.

Last year’s 53.6 million tonnes of it is a new record and represents a rise of more than one-fifth in the last five years. By 2030, this count of thrown-away electrically-powered hardware could hit 74 million tonnes annually.

The total for 2019 alone was enough to outweigh all the adults in Europe; and its mass can be imagined as a line of 350 cruise ships, each the size of the Queen Mary 2, stretching for 125 kilometres. It amounted to 7.3 kilogrammes for every human on Earth.

This waste added directly to global warming. Greenhouse gases equivalent to an estimated 98 million tonnes of carbon dioxide were released by unwanted refrigerators and air conditioners.

E-waste also constitutes a health hazard: at least 50 tonnes of toxic mercury seeped into the environment from thrown-away monitors, printed circuit boards, fluorescent lights and so on.

Right now, only 78 nations have legislation or national policies to deal with e-waste. Electrically-powered devices are still only a small fraction of the entire human technosphere: the sum of things humans have manufactured, fashioned or simply built from minerals over the last 10,000 years has been estimated at 30 trillion tonnes.

But electronic waste is already a significant cost and possibly an important potential resource. Another – new and entirely separate – study of metal sources on the planet estimates that in the next 25 years the global demand for copper, lead, zinc and nickel is likely to exceed the total produced so far in all human history.

Recycling goes overboard

European Union members and partner countries – the UK, Switzerland and Norway – have developed the infrastructure to manage another menacing discard, plastic waste, but 46% of this is exported out of the country of origin for recycling in countries with poor records of waste management, and a high proportion ends up in the oceans.

Plastic debris has been found on the deep seabed, on the beaches of desolate Antarctic islands, in the north polar ice, and in the tissues of sea creatures from sardines to whales.

Most of this is directly and deliberately discarded. But even the waste intended for recycling gets into the oceans. Researchers report in the journal Environment International that they made estimates of the fate of Europe’s exported waste in 2017.

They think up to 7% of all exported polyethylene – the commonest plastic in Europe – found its way to the oceans: at the very least 32,115 tonnes were tipped into the sea, and at the most 180,558 tonnes.

"This study suggests that true recycling rates may deviate significantly from rates reported by municipalities and countries where the waste originates," said one of the authors, David Styles of the University of Limerick in Eire and the National University of Ireland in Galway.

"In fact, our study found 31% of the exported plastic wasn’t actually recycled at all."