In 2007, while photographing floods in the UK (and with young children of his own), Mendel recalls: "I was thinking about the future and the lives they'd have when they're my age and I began to research climate change and got a sense of the threat. I wanted to make the imaging of climate change much more visceral and direct."
He adds that his work as a photographer was shaped by his job as a photojournalist on the politically tumultuous streets of 1980s Johannesburg. He has always being "compelled and drawn to react to social issues".
While the Submerged portraits have continued to provide the central visual narrative of the series, they're accompanied by other series of photos which reflect more abstractly the effects of floods on people - showing the physical marks of flood lines within the intimate spaces of homes, and a further series of work which records the effects of water on the personal photographs of occupants.
Memories are indelibly marked by the deluge - like their subjects, forever changed by the experience.
While he doesn't want the work purely to be seen within the context of climate change activism, Mendel admits that the experience of photographing in so many flood zones over the years has probably turned him into more of an activist than he's ever been.