A combination of environmental concerns and tough market conditions has forced multi-national Glencore to bring forward the closure of its West Wallsend underground mine. It started operations in 1969 and was expected to remain productive until 2021, but the company previously announced it was closing the mine at the end of next year. Allyn Hamonet from Glencore said the company is constantly revising its operations. "We actually forwent five million tonnes, which was about two years of operation," he said.