By Eric Onstad LONDON (Reuters) – Volkswagen has joined a group that sets environmental and social standards in mining as the world’s No.2 carmaker steps up efforts ensure its raw materials are sustainable, especially in electric vehicles (EVs). Big companies have come under increasing pressure from shareholders and consumers to meet stricter standards relating to the environment, social issues and governance (ESG). VW is the biggest member company by revenue to join the Initiative for Responsible Mining Assurance (IRMA), the carmaker told Reuters ahead of an announcement later on Thursday. Ot…