Adeyemi Adesina, John Orr, and Ryan Zizzo are all experts on concrete. They advise construction companies and architects on how to use materials efficiently and with minimal emission of carbon dioxide during construction and afterward, throughout the structure's lifetime. John Orr particularly emphasizes the value of reducing the amount of concrete used in construction, for it is one of the leading sources of greenhouse gas and global warming. It is possible in most cases to design buildings that meet al the standards but use much less concrete. Another source of reductions is the use of more concrete that does not require such a long period of curing. For the video, audio podcast, transcript and comments: https://tosavetheworld.ca/episode-532-use-less-concrete.