Fossil fuels are expensive. Much of their costs are hidden, however, as subsidies. If people knew how large their subsidies were, there would be a backlash against them from so-called financial conservatives. A study was just published in the journal World Development that quantifies the amount of subsidies directed toward fossil fuels globally, and the results are shocking. The authors work at the IMF and are well-skilled to quantify the subsidies discussed in the paper. The subsidies were $4.9 tn in 2013 and they rose to $5.3 tn just two years later. According to the authors, these subsidies are important because first, they promote fossil fuel use which damages the environment. Second, these are fiscally costly. Third, the subsidies discourage investments in energy efficiency and renewable energy that compete with the subsidized fossil fuels. Finally, subsidies are very inefficient means to support low-income households. With these truths made plain, why haven't subsidies been eliminated? We are talking enormous values of 5.8% of global GDP in 2011, rising to 6.5% in 2013. Petroleum and coal receive much larger subsidies compared to their counterpart fuels. There are two key takeaway messages. First, fossil fuel subsidies are enormous and they are costs that we all pay, in one form or another. Second, the subsidies persist in part because we don't fully appreciate their size. These two facts, taken together, further strengthen the case to be made for clean and renewable energy.