If you placed a weightless empty box on your head and filled it with the average cars exhaust emissions for one year, the result 4.6 metric tons would crush you

If you placed a weightless empty box on your head and filled it with the average cars exhaust emissions for one year, the result 4.6 metric tons would crush you like a pancake. If we're being charitable we could let you take a few breaths of what's in the full box just to ease your suffering. There are 1.4 billion such cars currently operating in the world.