On the corner of Park Avenue and 52nd Street in New York City, curious onlookers recently stopped in front of a giant green skull sitting in the bed of a truck parked outside the offices of Fidelity Investments, a global financial management firm. The “Skull of Satoshi,” named after the pseudonymous bitcoin developer Satoshi Nakamoto, is composed almost entirely of computer circuit boards and features the tall smokestacks typically found atop coal-fired power plants. The artifact is a project by artist Benjamin Von Wong and is a reference to the vast amounts of carbon emitted from mining the cryptocurrency bitcoin, an effort that Fidelity is now pursuing. Bitcoin is best known as a wild investment vehicle that — along with many other cryptocurrencies — can seemingly make or lose fortunes overnight in a market where values rise and fall rapidly and by large margins. But what worries environmentalists and others is the vast amount of electricity used to produce bitcoin and other similar currencies — energy that often comes from fossil fuels, and so has a corresponding impact on the climate crisis. As big financial brands speculate in the world of cryptocurrencies, environmental activists want to make sure they know they’re not just taking a financial gamble; there’s also an environmental risk. Some hope they can convince these institutions to try to reduce the impact of cryptocurrency mining. “For a financial institution like Fidelity to launch its own crypto platform is a big step. So now more than ever, we need their help,” said Rolf Skar, campaign director for Greenpeace USA, a nonprofit environmental organization. It’s a complex situation. But here’s a guide to the key questions. (ECB)