Australian: Together, they represent the most challenging streams of discussion at this weekend’s 2020 Summit. They also have generated the greatest public response. Of the nearly 10,000 submissions received by the 2020 steering committee, more than 1300 touch on the topics covered by the sustainability stream. Some have been drawn up around the kitchen table. Others are for the technocrats. Some are parish pump. Others have national implications. Together, though, they reiterate the intricacies …