John Melby, CEO at Xpansiv, discusses environmental commodities, registries, commodity marketplaces, and financial incentives for promoting environmental outcomes. Xpansiv operates the largest carbon offset exchange, covering 40% of the voluntary carbon market volumes. They also provide infrastructure for trading various environmental commodities. The podcast covers topics such as offset standards, buyer preferences, standardized contracts, market efficiency, pricing offsets, institutional customer base, traders, voluntary vs compliance markets, double counting prevention, and startup trading strategies.