Save Humans, Go Veggie

Something which is obvious, but nobody dare approach, is that there are just too many of us on the Earth with the current population touching 7 billion but how many more of us can our planet sustain?
Based on calculations of the Earth's available resources, the magic figure is 10 billion according to the United Nations Population Division, but that comes with the proviso that our planet can handle 10 billion vegetarians, not that many meat eaters.
The Earth currently has 3.5 billion acres of arable land available which produces approximately 2 billion tons of grains annually and if all that grain was dedicated to feeding humans and none to feed livestock, then 10 billion of us can happily live side by side.  
As it is extremely unlikely that everyone will agree to stop eating meat, the maximum carrying capacity of the Earth based on food resources will fall significantly short of 10 billion, somewhere around the 6-7 billion figure which is where we find ourselves now and that is without the complication of arable land becoming infertile due to the consequences of climate change and ensuing desertification and water shortages.
Current projections put the global population at 9 billion by 2050, and 10 billion by 2100 and then we would have reached our absolute limit as far as Earth's capacity to keep us all fed is concerned.
Throw in the issue that an increased population means greater production of the gases that cause global warming and global warming will mean less arable land, then the 10 billion figure is beyond reachable as less and less arable land leads to the current 2 billion tons of grain being reduced and therefore less of us fed.
According to the UN Food and Agriculture Organisation, meat is responsible for 18% of greenhouse gas emissions which is more than all the cars, trucks, planes and ships in the world combined so with every mouthful of cows anus or pigs eyeballs in your burger, you meat eaters are condemning all of us to a slow, painful, hungry demise.
It's time we grabbed the bull by the horn, or rather grab the fork off meat eaters because the population won't stop growing but we can all eat less meat to compensate for it.