trading worth us $100 million have been carried out in the global greenhouse gas emissions market since 1996, states a study commissioned by the World Bank. The study reveals that at least 60 transactions between companies, which account for 55 million tonnes of carbon dioxide ( co 2 ) equivalent emissions reductions, have taken place till now and the market is poised for further growth. "As more domestic emissions trading markets emerge, along with other opportunities for trading emissions permits recognised by governments, the market is set to grow despite continuing uncertainty surrounding international climate change policy,' says the study. According to the study, most of the deals have involved verified emission reductions ( ver s), which are audited by a third party such as an engineering or an accountancy firm. Nominal prices for ver s have ranged between us $0.60 and us $3.00 per tonne of co 2 equivalent. Trading in emissions of greenhouse gases is one of the provisions of the Kyoto Protocol.