New & Improved FormulaA few years ago, soon after the global financial crisis, the US Cash for Clunkers program received a lot of attention. The main aim was more economic than environmental, and it was seen by many as a handout to Detroit automakers, but it did help take off the road some of the most polluting vehicles out there (the worst old clunkers can sometimes pollute more than hundreds of well-tuned more recent vehicles, and since most of the lifecycle impact of a car comes from operation and not manufacturing it, this can make sense).
A program in the UK goes further. Rather than trying to encourage people to scrap their old junker and then buy a new one, they trade you some trees. Trees for Clunkers, in other words, though the official name is "Scrap Car, Plant Tree". It doesn't absolve past sins, but it does help the environment via all the things that we know trees provide (carbon capture, air filtering, various ecosystem services, protection against soil erosion, reducing the heat island effect in cities, etc). Definitely an improvement on the US model, and something that should be exported from the UK to other countries!
The photo above wasn't taken in the UK, but I think it illustrates well how much of a difference urban trees can make.