A lot of species (including some plants!) eat animals.
So eating whatever we eat is purely natural, or at least should be.
What of course is not natural is the mass industrialisation of the food industry, and the damage that is doing to the planet along with pretty much everything else humans do.
And without bringing existential morality into human behaviour, it is plain stupid to wreck this sphere we live on.
Can we justify six billion of us, then seven billion, then eight billion and continuing ever upwards? Well the only likely outcome of that would be far greater famine and depletion of resources, and actually running out of some. And the energy needed to support us all would (under current practices) lead to uncontrolled climate change.
So how can humanity build a different sustainable future?
Well populations in the wealthiest countries are fairly stable (albeit still gradually increasing). So helping other countries to develop further and helping to reduce or eradicate poverty around the globe should slow down population growth significantly.
Energy, there's no reason why all our energy needs cannot be met through green means. Some countries have already reached the point of generating 100+% of energy requirements from green energy (including Scotland for example). And there is also the possibility coming along of nuclear fusion. Wholly different from the existing and centuries-long polluting nuclear fission, fusion 'simply' makes helium from deuterium. If it could be done properly, then untold energy would become available to us.
And whatever technology comes along, what is now clear is that we need to power everything using green electricity.
And for vehicles that could also include green produced hydrogen to power them.
Fuel tanks of hydrogen may prove a better solution than batteries unless far better batteries can come along.
All trains can and should be electrified. As the nation that invented trains, it's bizarre just how little of our rail network is electrified.
All buses and lorries should go quickly to electric or hydrogen power.
Cars can be changed over a longer period (and government really needs to step in with imaginative schemes to fund new cars for people - existing electric models are just way too expensive for most people).
And then back to food. We all eat too much processed food (whether meat or not meat).
It is our whole diet that needs taking back far more to natural.
And should meat cease to be part of that diet? Well, for those of us who do eat meat, eating less is probably beneficial. Eating none at all? I don't know. I've shared houses in student days with vegetarians and vegans.
I've a son and daughter-in-law who are vegan and vegetarian respectively. I've a sister-in-law who is even more extreme and will only eat fruit that's fallen off trees etc.
Could I stop eating meat myself? Just not sure. Over last couple of years though, we have stopped buying supermarket meat & processed meat, and now only buy from a local butcher. At least that ensures high quality and from animals that have been reared in the best ways (although of course they're still being killed and eaten - back to the morality question). But at least we feel we've made a small improvement in our food habits. We also have mainly vegetarian meals during the week. And supermarket ready meals have been excluded completely.
The added concern foodwise now of course is the abolition of food regulations by our extremist brexiteer government and the importing of food made in the grossest of ways and it will be harder and harder to avoid such food (you can guarantee it will be served up in privatised hospital catering for example).
And then to the morality question.
Me, I love animals and all their wonderfulness. Humans definitely are not the most intelligent species nor are we superior. Probably all animals have similar intelligence and all feel happiness and joy and sadness and depression and every emotion in between. We certainly know dogs and cats dream and that's probably true of all animals with a brain.
Love is common across most or all animals.
So definitely one for personal choice. I certainly would object to animals being kept in horrible conditions. They should be allowed to live happy normal lives. Whether we should then eat them or not - pass - although of course the ones we do eat would likely not exist if we hadn't reared them to start with. But maybe one day sheep cows and pigs will get treated the same way horses cats and dogs are now and live with us without being also our food.
Sheep can certainly be reared purely for wool. Cows can be used as oxen, doing work for us, or providing milk.
Pigs - well they're good at using up things and maybe black pudding can be made from pig doing blood donoring!!