I came across this piece by JG Ballard in the The Drowned World (1962) on the very interesting Some Landscapes blog, and originally from the Ballardian website, both of which I need to investigate further. The above image is by Squint/Opera from a series depicting imaginary scenes in London in 2090, when rising sea levels have inundated the city. The The Drowned World tells the tales of London after a flood. Ballard was always superb on nature taking over.
The bulk of the city had long since vanished, and only the steel-supported buildings of the central commercial and financial areas had survived the encroaching flood waters. The brick houses and single-storey factories of the suburbs had disappeared completely below the drifting tides of silt. Where these broke surface giant forests reared up into the burning dull-green sky, smothering the former wheatfields of temperate Europe and North America. Impenetrable Mato Grossos sometimes three hundred feet high, they were a nightmare world of competing organic forms returning rapidly to their Paleozoic past, and the only avenues of transit for the United Nations military units were through the lagoon systems that had superimposed themselves on the former cities. But even these were now being clogged with silt and then submerged.