This is all very well and good...as long as you're vegan with this change. You can not be an environmentalist or claim to care about the planet if you are not vegan. Even if every single person on the planet stopped driving cars and taking any form of transport, including flying planes and taking trains...we'd still be in a world of shit because that wouldn't help. Animal agriculture is the leading cause of every single environmental issue we are facing today as a species, 40% of the world’s land surface is used for the purposes of keeping all 7 billion plus of us fed, even if not all of us contribute to the animal agriculture industries . With the amount of people currently living on the planet and the supply and demand that comes from nations that consume animal products on a daily basis there is just no way to reform a system that is flawed from the very foundations. and one that disregards the bodily autonomy of innocent beings. This is why 'humane farming' aimed at assuaging the guilty consciousness' of those looking to 'care' but not give up their favorite meals will never work. There is no other single human activity that has a bigger impact on the planet than the raising of livestock.
The planet we live on doesn't belong to us alone, and that's why essentially environmentalists do what they do. We share the planet with each other and other beings who all have the right to live in harmony with their surroundings. So with every burger,steak or whatever the chosen animal product of choice is, you are taking away from future generations, the chance to live where forests are not a tenth of their original size due to being cut down to make more space for new animal factories or the pleasure of breathing in fresh clean air, drinking water free from antibiotics and living on a planet that is not dying at an alarming rate. Think of the world you're contributing to. The planet can not support the mass extinction currently happening due to human greed much longer. The answer is as simple as an easy lifestyle change...are you vegan yet?