2. By calling it a subsidy they treat the cost as a precise quantifiable value which is most certainly is not.
The authors have taken a completely justifiable position and then thrown away their legitimacy by misrepresenting the data in an attempt to strengthen their position. You can agree with the top-level premise and agenda but how we get their is important.
That is completely inaccurate.
The very first line of the summary of the referenced article says:
>> This paper updates estimates of fossil fuel subsidies, defined as fuel consumption times the gap between existing and efficient prices (i.e., prices warranted by supply costs, environmental costs, and revenue considerations), for 191 countries.
I don't disagree that the externalities are worse for fossil fuels than other energy sources, and that's a good reason to decarbonize our energy supply. But externalities are exactly that: impacts external to the cost of power generation. When someone says "we subsidized X industry by $Y" to me it means that $Y worth of goods and services was given to that industry. In reality, the fossil fuel industry received nowhere near that amount of money. This "subsidy" is really a speculative cost of externalities. Especially when the projected cost of externalities vary widely, equating externalities with subsidies comes off as intellectually dishonest. If externalities account for effectively the entirety of this so called subsidy, you're better off calling it an externality rather than trying to redefine a term.
This is totally reasonable. You're usually expected to fix the things you damage in any activity you do. The fact that fossil fuel users are not expected to do so is clearly a subsidy.