It depends on where you live. Here in Switzerland we have two systems. One comes from the government, who tries to collect money from people who produce higher CO2 emissions and use it in different projects for the environment like planting trees or install solar batteries on roofs.
The other one is to look for yourself and try to reduce your emissions without help from beyond. As we know, the little things can make a big difference, such as showering less long or using the public transport more often. That way you don’t have to spend so much money and you know a change has really been made. As for the political solutions, you never know how exactly your money has been used and whether their initiatives make sense.
myclimate.org