[Dah00n]

Yes but the alternatives are much easier for a country to afford, understand and build when at a lower tech level (like China compared to the US when old powerplants were build in China for example).

The difference is that taxing something means less people are likely to buy it and when they do we make money, while giving a tax break make the product more competitive while costing us the income we might have had. One is a carrot, the other is a stick. It might not matter on income in the end but it will help push for greener products while taking the high road.

[adrianN]

Giving a tax break needs to by financed by raising some other tax or printing more money, which causes inflation. There is no free lunch.

[Dah00n]

You could prevent a lot more pollution with the same amount of money if the money goes to low hanging fruits in countries with older power infrastructure than trying to tweak something brand new. You don't need to use extra money, just use it smarter. There're lots of ways to finance this smarter if trade wars and nationalism wasn't the top priorities.