The desire to imagine
                                                the future.

So begins 'Root End', a poem towards the close of Jorie Graham's Sea Change, the latest of her twelve collections. The book is written out of that white space - also a gap in time - across which the imagination strains to leap. Graham's poetic idiom, with its signature shifts and hesitations, relies on the suggestive power of such gaps. But sometimes they are so wide we can barely follow her across. In her previous book, Graham described the struggle of scientists to develop 'a language that will still communicate' in 'hundreds of millions / of years'. That span goes beyond the limits of conceivable history and into a purely geological time. Yet our containers of buried nuclear waste will still need to bear the message, 'don't open this, this is lethal beyond / measure' ('Praying (Attempt of June 14 ' 03) ' ). In Sea Change, however, reaching the future is often as easy as stepping off a pavement. Its poems picture a posterity we can already see at work in the present: 'fish are starving to death in the Great Barrier Reef, the new Age of Extinctions is / now'.

The Sea Change poems reprise many of Graham's preoccupations in the two books that preceded them. Never (2002) was similarly haunted by a vanishing natural world. ...