Treat Meat as a treat
Yes. A vegan diet is better for the environment, animal rights and it's good for your body too, as a well balanced diet of greens, nuts, seeds and carbs can give you all the nutrients to live a healthy life. But the world is far from leaning in that direction and we need to take baby steps first. We can't just change the whole world's diet within a few years because changing the world's production supply chain needs a huge logistical strategy, costing time and money - and we will need to change the will of the people, which is incredibly difficult.
If you love eating meat, that's okay. But if you want to fight climate change, you should know where your meat comes from and how the animals have been treated. Search for organic labels, so you know they haven't been fed hormones, antibiotics, made to sleep in their own poop or stuck in cages sitting on top of each other the whole year round. The cuts will be of higher quality, and will obviously be more expensive, but also much healthier for you.
Which meats to eat
Eating less meat overall is very important, but you should also seriously tone down on red meats as beef, lamb and goat are the worst offender in terms of the environment. Choose for white meats instead, like chicken and turkey.
Beef is the worst off all when we look at energy use, water use and pollution, land use, acidification impact and overall, its effect on global warming. Cows are huge, and because of their multiple stomachs, they eat more than other animals with just one stomach. This means more energy, fertilizers and pesticides are required to grow their food. And they poop a lot. Believe it or not, their 27 kilos of droppings per day release a lot of methane. Cows also aren't very efficient breeders, as one cow can only birth one(ish) calf per year.
Lamb is pretty bad in energy use and water pollution, but scored the highest of all meats in terms of pesticide use and nonrenewable resource usage - as in, they don't need to use fossil fuels to be kept alive/warm/sheltered.
Pork is the most consumed meat in the world and is much greener than beef or lamb. Pigs don't poop/burp/fart as much, they eat about half as much as cows do and they reproduce more efficiently. - between 20-30 piggies per year! The unsaturated fats and protein are very healthy for us, but make sure to buy non-processed pork, as the added sodium in bacon and sausage doesn't do much good to the human body.
Chickens breed like crazy, as mommas can produce hundreds of chicks per year. They're also very efficient weight gainers, so don't need to live long - and eat much - for us to enjoy our drumsticks. They're also very lean and contain a lot of protein and is low on fats.
But still, the way most animals are being bred is not the way forward. Think about the poor animals stuck in cages, fed hormones to grow faster, and needing to sleep in their own poop. The reason we haven't eaten any pork in years is because pigs are very intelligent, more so than dogs, and can problem solve as well as chimpanzees. They're often bred in small areas where they're forced to do their business where they sleep, which they wouldn't if they had enough place to roam - that's how smart they are, the group would decide where to place their toilet, and steer clear of that area for all other activities.