The real-world impact of the cryptocurrency business. Edwin Lane reports from Iceland, which has attracted power-hungry Bitcoin mines looking for a cheap source of electricity. Arni Jensen from the Borealis Data Centre shows him around a cryptocurrency mine near Reykjavik, and Johann Sigurbergsson from the geothermal energy company HK Orka describes the massive growth in the demand for electricity the miners have created. And the mayor of Plattsburgh, New York, Colin Read explains why his city is the first in the world to announce a temporary ban on cryptocurrency mining, amid concerns over its electricity supply.

(Photo: An illustration of Bitcoin mining, Credit: Getty Images)