I'll note that this is article is concentrated on individual action, not on political action to change policy, which has a far bigger impact than individual action can.
By far the most effective thing form the least effort is don't waste food. I.e. eat your leftovers and meal plan to reduce waste. It saves time, money and GHG.
The other easy effective thing is eat less beef. It is as simple as getting chicken instead of beef at chipotle or getting a chicken sandwich instead of a cheeseburger at a drive thru. Order online ahead of time so you can save time, money,.and GHG emissions sitting in a drive thru.
First because, per calorie produced, organic farming emits 12 to 40% more green house gases.
(Depending on the study).
Second, because you'll be less healthy and die sooner.
This only works if you pretend the organic farm depletes soil carbon and emits NO2 at the same rate as the fertilizer farm, fugitive methane doesn't exist (anything with fossil gas in its upstream suplly chain has its emissions under-reported by a factor of about 3), and that the vast tracts of land poisoned and degraded by fracking are completely fine.
You also have to cherry pick small scale lifestyle blocks for your analysis and assume that the land previously degraded by industrial agriculture could be used further at the same yield.