Which country burns the most fossil fuels? This list answers that question. By burning fossil fuels we deplete our natural resources, so which countries burn the most fossil fuels? The most oil and natural gas? The answer may surprise you. This list uses what percentage of a countries greenhouse emissions come from fossil fuels. In the United States, more than 90% of its greenhouse emissions come from fossil fuels, but the US is not even close to the top of the list.