It turns out even electric cars can leave a footprint because the batteries require materials that have to be dug out of the ground.
"As part of the mining process you need a lot of hydrochloric acid," explains John McElroy, longtime auto industry observer, and host of Autoline Daily.
He says those new Lithium Ion batteries in all-electric cars like the Tesla need huge amounts of graphite from China. But the mines kick up so much pollution, even China has had enough.
"It not only pollutes the air, it causes crop damage to the extent that the Chinese government is now closing down all kinds of graphite mines," says McElroy.
As for the nickel used for the nickel metal hydride batteries in older hybrids a lot of that comes from smelters in Sudbury, Ontario. "And if you look at pictures, it looks like a moonscape," he says.
But at least you can console yourself that the batteries can be recycled, maybe? Please?
"There is no recycling infrastructure anywhere in the world to handle lithium ion batteries," says McElroy.
So, as someone who's driven a hybrid for 13 years, I'm ready to make a deal with my gas guzzling counterparts. I won't ask you about your carbon footprint, and you don't hassle me about my hydrochloric acid footprint.
And please don't mention Sudbury.
And try not to notice that pile of un-recycled batteries.
We'll all just accept our mutual guilt.