Skipping pleasantries like “please” and “thank you” when talking to chatbots could save enough energy to power the annual needs of 760,000 residents in sub-Saharan Africa, highlighting the massive but often hidden environmental toll of artificial intelligence, according to a new UN report. Released by the Institute for Water, Environment and Health under the United Nations University, the UN’s academic arm, the study published on Wednesday also warned that the true cost of AI extended far beyond...