Taxing fuel at such an astronomical rate will certainly lower the amount of fuel use, but how many businesses will have to shut down because customers can't afford to blow $14 on fuel that they weren't spending before just to patronize those businesses?
This is actually massively under-stating the problem. The costs of all kinds of things go up proportionate to the tax on fuel, and these costs primarily impact the poor and the middle class (effectively increasing concentration of wealth in the super-rich).
It's not just customers that have to spend money on fuel, it's all the people that keep the public and private infrastructure of society in working order: the utility workers, the plumbers, the carpenters, the electricians, the safety inspectors, the fire fighters, the police officers, the medical personnel, and so forth. In most cases, it isn't practical for these people to do most of their work remotely (or even to live close to their jobs).
There are also people who need to move around as part of keeping the natural environment healthy, such as forest rangers (doing all kinds of jobs), scientists, hunters (hunters help to keep animal populations under control), and volunteers doing all kinds of things. All this requires vehicle transportation.
In some parts of the USA, goats are used at sites overrun with noxious and invasive non-native weeds, as a form of weed control that doesn't involve man-made chemicals (with their unknown and potentially disastrous long term environmental consequences). The goats need to be moved from site to site, and taken care of, which requires movement of people and supplies. If we increase the cost of innovative approaches like this to dealing with environmental problems, we force the use of more man-made chemicals. A gas tax policy intended to help the environment could actually end up harming it!
Then there's the issue of bringing food to the markets. This applies both to the big commercial markets, and to the small farmers markets that are so important to getting fresh, organic food grown by people one actually knows (and also helping independent farmers outside the corporate farming system -- with all its well documented problems such as over-use of anti-biotics -- to survive).
There's also the issue of needing transportation to get to places where one can do healthy exercise (such as swimming pools), thus maintaining the physical fitness of members of society and reducing the negative health and economic impacts of obesity. The poor have a lot less time available to include exercise in their lives than the rich, and anything that makes it harder to do this has negative consequences to society.
There's also the issue of getting to school for classes, something particularly important not just for the young, but for all those that need re-training or need to develop new skills to have reasonable prospects of improving their lives over the long term (and improving their children's lives). Much of this education, such as trade school education, can not be conducted remotely because of the need for hands on activities (we should be vastly improving our capability to do remote education, but that is a separate issue). The poor and the middle class have the most need for continuing education, and thus are hurt the most by these policies.
In short, a sales tax on gas not only hurts the poor and the middle class directly in terms of getting to their jobs and to places where they can buy food, but hurts these folks (and society in general) in all kinds of indirect ways.
A lot of folks in our society are making claims that a tax on gas is friendly to society and the environment, and producing all kinds of propaganda to support these claims, but they don't seem to have the intelligence to be think about the negative consequences of doing this. These policies are not necessarily friendly to society, and in some ways they aren't even friendly to the environment. Perhaps we should view people that favor these taxes as people that hate society and hate the environment!
If we're going to have sales taxes at all, these should only be imposed on a very small set of luxury items such as commercially produced alcohol.
A far better approach to the fossil fuel issue is to tax based on income, with the wealthy paying more, then use that tax to fund research and development of technologies that will allow society to reduce its dependence on fossil fuels over the long term. In addition, we might allow tax deductions for money donated directly to such research and development (since government is not always the most intelligent or efficient at allocating funds, letting people have some say in where their money gets spent makes a lot of sense). If there is a need for more government control over the oil companies, that can addressed as a separate issue.