This is essentially a short-term over long-term rewards type thinking. By choosing the larger car you are effectively creating a world that is unsafer for your child, both in terms of if they are not in a car on the road, but also in terms of increased global warming.

I would also like to see statistics if kids in families with large SUVs are actually safer. There were enough cases of parents accidentally driving over the kids because they didn't see them that it might very well change the statistics.