This paper identifies 40 economies that depend heavily on the extraction and exports of fossil fuels (FF).For the average country, FF generate 14.3 percent of GDP in rents annually, accounting for more than 60 percent of exports and likely more than one third of total government revenue. Aside from a handful of primarily high-income countries, most countries have little or no savings to help them cushion the transitory cost associated with an inevitable steep fall in demand and prices for their resources under an ambitious global decarbonization scenario, i.e., any scenario compatible with the Paris Agreement.