A growing number of experts – including those at the International Monetary Fund, the OECD, and the World Bank – agree that no climate plan can be successful without an effective and efficient carbon-pricing system. The IPCC has concluded that if a single global carbon price is not established soon, it will be virtually impossible to prevent global warming from surpassing 2ºC above preindustrial levels – the threshold beyond which the most devastating effects of climate change would become unavoidable.