[ismyrnow]

I'm surprised the article doesn't mention density of cattle farming. I know it's a complicated issue, but my understanding is that industrial animal production affects climate more than transportation does.

http://www.fao.org/Ag/againfo/resources/en/glw/Density_maps/...

https://www3.epa.gov/climatechange/ghgemissions/global.html

[jonknee]

Because this article isn't about greenhouse gasses? The article is about particles in the air, mainly from vehicle emissions.