Originally Posted by Ziggy

Actually, it is. Take for instance the Emission Trading Scheme (ETS) that was implemented a year or two ago in the EU. Now, not only do they tax you on the fuel you purchase, but you have to buy carbon offset credits against the emissions of burning the fuel. This applies to all aircraft operators operating to/from and within the EU. This was one of the driving factors behind Brexit. The monies raised by this program do not necessary have to be used in conjunction with any climate program, but may be used on how the government sees fit. By not allowing natural forces to drive the industry (supply & demand, or cost / profit margins), a select group will use taxation and other government programs to dictate business practices.
Now I certainly enjoy clean water to drink and fresh air to breath, I believe in government to protect the citizens against bad business. To that extent, it should be either allowed or not allowed.

To tie this in with the subject at hand, I believe cost/profit margins will encourage Turboprops back into the U.S. industry. But to have the government dictate that they be used for the betterment of society, this is a double edged sword that can be turned against you.