Climate activist Greta Thunberg has called on German engineering group Siemens AG to stop, delay or interrupt the building of a coal mine in Australia. 'On Monday they (Siemens) will announce their decision. Please help to push them to make the only right decision. #StopAdani,' Thunberg on Saturday. Engineering giant Siemens will decide by Monday on its involvement in the development of the coal mine being built by India's Adani, its CEO Joe Kaeser said on Friday. The Australian government last year approved the construction of a new coal mine in Queensland by Adani that is expected to produce 8-10 million tonnes of thermal coal a year. Australia is one of the world's largest carbon emitters per capita because of its reliance on coal-fired power plants.