I'll agree with you about Veganists
I've always referred to them as such because it is, let's be honest here, almost a religion and, like Xian fundies, and creationists (which are, almost always, one and the same thing), they refuse to listen to any counter-arguments, all of which are likely to be based on ACTUAL SCIENCE ("Christian/creation science" is another oxymoron). The only way veganism will save the planet is by killing off the human race.
Please forgive me - I know you're all bored of my favourite soapbox - but the truth is this: every organism on Earth has its own unique dietary blueprint, set down by evolution and genetics; Homo sapiens didn't evolve to be herbivorous, nothing in our physiology is 'designed' (for want of a better word) to derive nutrition from plants, they have extremely low density, both in terms of energy and nutrition, and humans lack any physiological features for deriving either from them, at least in any quantity worth bothering about. Not only that, but plant proteins (mostly) aren't complete - herbivores don't require the same amino acids we do, nor do they require the same vitamins and minerals (there's no plant source of 'true' B12, for example, and we can't really do anything much with non-heme iron; furthermore, many plants - grains and legumes (particularly soy) - contain substances which are toxic to humans if consumed in large quantities (grains contain phytates which prevent the body from absorbing many vital nutrients (many mimic B complex vitamins, for example, tricking the body into believing it's assimilating more Bs than it really is, leaving people deficient), spinach, and other leafy greens to a lesser extent, contains oxalate preventing iron absorption by mimicking iron (oxalate also prevents the absorption of iron from any iron-containing foods the spinach is eaten with, so greens and steak isn't a sensible idea) as well as leeching Fe from the body. Soy contains phytoestrogens (those hormones touted as being good for you because they're "clinically proven to lower your cholesterol. You don't need your cholesterol lowering, high cholesterol - except in very exceptional circumstances - is a GOOD THING, as the higher your overall cholesterol, the lower your risk of developing heart disease). Phytoestrogens bugger up your thyroid as they mimic thyroxine, tricking your pituitary gland into believing it's telling it to produce too much T4, so it produces less TSH. Eat soy for long enough and, eventually, the opposite will be the case - your thyroid will quit producing T4 altogether (which means your TSH will shoot stratospherically high and you'll develop hypothyroidism).
(If you want an IT angle, Steve Jobs likely developed pancreatic cancer because he was vegan; an all sugar diet (which is what a vegan diet is - all carbs turn to sugar once consumed) will, obviously, hammer the pancreas far harder than a standard diet (which is still FAR too carb-heavy) and, when you abuse an organ like that, bad things are liable to happen. Despite what the NHS wants you to believe, eating meat DOES NOT cause cancer, of any kind (what the meat might have eaten, or been injected with, might, hence it's always best to eat grass/naturally-fed if at all possible). A vegan diet is also devoid of B12, which is anti-carcinogenic).
Because a vegan diet is so nutritionally poor, far more of the planet would need to be destroyed to accommodate humanity's nutritional requirements (just try telling a vegan much of their food contains palm oil and see their reaction - if the orangutang becomes extinct, it'll be vegans who are largely to blame). A vegan will tell you there's more protein in broccoli than steak; even if that was true (it's not) only around 10% of that protein will be assimilated, and it's not complete (I've a chart somewhere I saved when I was in the habit of trolling vegan FB groups, which makes the extraordinary claim that a cucumber is 24% protein, thus proving being vegan makes you extremely stupid (or perhaps vegans don't believe/think/know a cucumber is 99% water). The owner of this one particular group also had a dog and a cat, both obviously fed a vegan diet, and here was I thinking that veganists were vegan because they didn't like being cruel to animals (I did use to point out that humans are animals too so, by being vegan they were, in actual fact, being cruel to an animal… they never understood the logic…). I never saw any photos of the cat, but the dog… well, if I'd been in a position to, I'd have had her up on cruelty charges, the poor thing looked almost DEAD! Thank FUCK she didn't have kids (feeding kids a vegan diet is abuse as far as I'm concerned, as you're denying them adequate nutrition. A woman in France was a jailed in 2011 for 10 years for manslaughter after her 10-month-old daughter died of pernicious anaemia; her mother was a raw foodist, and she was one of those who believed in breastfeeding for as long as possible. She also didn't believe in hospitals so, when the child became sick, she wrapped her in boiled cabbage and bentonite clay poultices (to "draw out the toxins").
Us obligate carnivorous omnivores (I've always referred to the human diet as such, as we can live without plants, but NOT without meat) won't be the ones who'll destroy the planet.
I nearly gave you a down-vote for the apostrophe in 'trees'. I have not the foggiest why some think that, because a word ends in a vowel its plural requires an apostrophe. Apostrophes, in standard English usage, denote possession or omission, neither of which applies here.