Miners of the cryptocurrency each year produce 30,700 tonnes of e-waste, Alex de Vries and Christian Stoll estimate.That averages 272g (9.5oz) per transaction, they say. By comparison, an iPhone 13 weighs 173g (6.1oz).Miners earn money by creating new Bitcoins, but the computing used consumes large amounts of energy.They audit Bitcoin transactions in exchange for an opportunity to acquire the digital currency.
These deep, kilometres-wide channels, known as tunnel valleys, were cut by fast-flowing rivers that ran under Northern Europe's ancient ice sheets.Today, the landforms are all hidden by the North Sea's bottom-muds, but new survey work has traced their outline in remarkable 3D detail.Scientists say the channels should give us clues as to how modern-day ice sheets, such as Greenland, will decay.
The incident centred on the Russian-built Zvezda module which provides living quarters, Russian media report.The ageing space station has suffered a number of failures over the years and a Russian official recently warned of outdated hardware and failing systems.These include air leaks, misfiring engines and cracks.
A carbon budget is the cumulative amount of CO2 that can be released in a period of time while keeping within a temperature threshold - in this case 1.5C.Many fossil-fuel extraction projects already planned or in operation are likely to hurt the world's chances of meeting internationally agreed target limits on global warming set out by the 2015 Paris Agreement