ABSTRACT
I have been asked to end this book on the Challenger legacy with a look into the future. The planning horizon for oceanography is about twenty years, set by the lead time to develop and introduce new technology, and to fund great endeavours. I shall therefore limit myself to the next twenty years, and concentrate on major challenges that need to be addressed now, which will take twenty years or longer to resolve. And because Challenger was about the global perspective, I shall not address the future of coastal oceanography.
