Carbon Finance: A “hybrid’ trading system with ceiling and floor prices to control carbon prices would stimulate more investment in cutting emissions, according to a white paper by PricewaterhouseCoopers (PwC). The consultancy proposes that governments could set a price floor and ceiling on trading systems. Although the trading system could have a ‘cap’ on total emissions in usual circumstances, if the price of allowances in the system reached the ceiling, governments would sell unlimited allowances …