This is a process of improvement which has been continually making things better since manufacturers starting making their cars more fuel efficuent, and considering the CO2 output of their vehicles. It is a process which we hope keeps building momentum - In 20 years time we hope most of the electric cars being purchased today will still be on the roads, and by that time many will have saved the CO2 that was released in their manufacture.
What I am saying though, is scrapping all of the old cars on our roads, would be madness, and yet this is exactly what people have been encouraged to do over the last decade. Government scrappage schemes are completely rediculous, and as a result hundreds of perfectly good cars have been destroyed; effectively wasting CO2, because the life of these cars was ended premeturely. Worst still, large quantities of CO2 would then have been released into the atmosphere during the manufacture of the brand new replacements... and there would even be CO2 released during the disposal of the old cars.
Therefore the data on this site is designed to help you make an informed decision about the car you drive. You want to buy a brand new car? Thats fine. You might want to consider some of the latest technology like the Tesla Model X or the Nissan Leaf. The short term costs, and CO2 production might be high, but in the future your purchase will have helped the world to improve, and you will be able to enjoy the latest in technology, and performance. There are other benefits, such as increased reliability, cleaner air for people to breath in the areas that you drive, and in some cases, blistering performance.
But if you cannot afford a new car, do not worry. If everyone bought new cars, there would be a huge amount of unnecessary CO2 produced. It's all about doing your research, and making an informed decision.