Most I can tell your numbers are just entirely made up, I've never heard of any serious study ever estimating global green house gas emissions from agriculture under 10%.

https://www.c2es.org/content/international-emissions/

>Globally, the primary sources of greenhouse gas emissions are electricity and heat (31%), agriculture (11%), transportation (15%), forestry (6%) and manufacturing (12%). Energy production of all types accounts for 72 percent of all emissions.