"Combining isotopic evidence from ground surface measurements with the newly calculated fire emissions, the team showed that about 17 teragrams per year of the increase is due to fossil fuels, another 12 is from wetlands or rice farming, while fires are decreasing by about 4 teragrams per year. The three numbers combine to 25 teragrams a year -- the same as the observed increase"[1]

The 'cows farting' story is not a major methane source.

https://www.nasa.gov/feature/jpl/nasa-led-study-solves-a-met...