This claim is not true. I mean, it's so easy to go and read withouthotair.com and see how this stuff can be calculated on the back of an envelope.

Then you can try a little bit harder and do 2nd, 3rd and other order effects and get a bit more precise estimates.

To say that a 2 ton car moving represents a tiny part of CO2 emissions and that breathing is killing the planet is ridiculous.

perhaps they are confusing CO2 for methane emitted by large fields of livestock (at the cost of their consumption of vegetation no longer available to help capture CO2) which is a non-trivial portion of greenhouse gas emission.