Thank God for global warming. It may finish off the planet. But in the meantime, it could save the European Union. Without the new sense of mission provided by the battle against climate change, the EU’s 50th anniversary celebration in Berlin next Sunday was shaping up to be a dismal affair.

Like many 50th birthday parties, the EU’s bash was always likely to be a mix of self-congratulation about the past and foreboding about the future.