Britain’s new polar ship, the Sir David Attenborough, headed for the open seas on Tuesday to start trials after a storm delay, before making its maiden voyage to Antarctica next year for climate change research.The £200 million (US$260 million) state-of-the-art polar research vessel, with its red hull and a bright yellow crane on its stern, sailed past Liverpool’s historic docks and out into the sea, headed for north Wales.Officially the ship is named after the veteran BBC naturalist, but to…