Thinking inside the box

The most intriguing presentation of the UKPSF conference was by Charlie Paton (Seawater Greenhouse Ltd). Essentially, his view was ‘Water crisis? What water crisis?’. The water problem is not that we don’t have enough water – the Earth’s surface is >68% seawater, after all – but that we have too much of the wrong sort of water. Appropriately, his company turns seawater into freshwater. But this is not the more familiar, expensive desalination plant, instead the fabric of their greenhouses (described as ‘porous cardboard’) does the salt-removal work, converting seawater into usable fresh water to satisfy the needs of the crops grown within. This work has also helped the desert bloom; not only have they generated high yields of crops inside the greenhouses in otherwise arid areas, but the evaporated water from the greenhouse irrigates the surrounding land encouraging plant growth there as well. Plus, the salt in the walls of the greenhouse act as a natural biocide protecting the precious crops. At last, a greenhouse effect we can be pleased about!