I agree with Avery that irrational ideologies are the main danger to human progress in the near future. The final session Biodiversity and multiple land use demands discussed the interaction between agriculture and preserving biodiversity. The summary by the conference organizer described the different views, except Avery's, in a way that will be helpful to people who haven't time to read the individual papers. From the point of view of the long term sustainability of human progress, the 25 year time frame of the conference was too limiting. In particular, no-one proposed any substantially new ideas.
Many plants can grow in seawater, but none of the crop plants can.
Maybe wheat, rice, potatoes, etc. That would solve the agricultural water problem. This is a pure speculation on my part. The number of hits on this page since 1995 December 25.