[Retric]

Cars last far longer than 15 years on average. For the average car in the US to be almost 12 years old means they must last on average about 25 years as the rate of car production has been increasing.

Secondly, GDP to CO2 figures are a poor fit. Agriculture for example is directly 10% of US CO2 emissions but only 5.4% of GDP.

[perl4ever]

I think 15 years is a good estimate.

First thing that comes up when I Google:

"While an average lifespan of vehicles is not given in the IHS report, a 2014 Automotive News article stated that, at that time, the peak lifespan or “scrapping age” of a vehicle was 13 to 17 years old"

[Retric]

Scrapping age relates to when the car is no longer worth repairing after an accident. In the US many cars also get exported when their not worth keeping in used car lots. Still a huge number of older cars are on the road and many of them are far older than 25 years.

From 2014: https://www.nbcnews.com/business/autos/old-clunkers-rule-roa...

How many of these "pre-'99" models are still around? 53.3 million.