In September 2015 I watched Cowspiracy, a documentary about the impact of livestock on climate change. It explains why cattle rearing is so damaging to our climate and doesn’t get the attention it deserves. It’s well made and is likely to achieve its goal to get the viewers thinking about their diets.
The documentary is reasonably well researched, but there is valid criticism on the sources used in Cowspiracy. An earlier version of the film claimed that livestock caused 18,5% of global greenhouse gas emissions, based on an FAO report. The revised version of the film doesn’t mention a figure, but the creators admit on their website that the FAO lowered the figure to 14,5% later. Unfortunately they do continue to support a single study which concluded that livestock is responsible for 51% of greenhouse gases, which is not credible to me after all the criticism I’ve read. Even so, the 14,5% figure is still more than all greenhouse gas emissions from transport, which are 13% according to the sources used for the film.
Another issue is the claim that you can’t be an environmentalist if you eat meat. As said elsewhere, I don’t think it is black and white. If there is mountainous land which is unsuitable for agriculture but which can be used for entirely grass-fed cattle, I don’t see a problem. The same goes for hunting and fishing responsibly. In practice supply of animal food from these two former categories is very limited in the Western world, of course.
You might take an issue with some of statistics and sources used in Cowspiracy, but its message that we should adopt a vegan diet (or in my eyes, at least drastically reduce our consumption of animal products) still stands. There is overwhelming evidence for the extent of the problems caused by livestock. As you can read on their page about the facts, cattle requires enormous inputs in land, water and fodder crops when compared to growing plants. Feeding half our global grain supply to cattle is crazy.
An recent study from Erb et al. (2016) in the prestigious journal Nature sheds more light on the problem. They studied the options for feeding the world in 2050 without further deforestation. A Western diet for everyone is possible, but only if “cropland yields rose massively and cropland expanded strongly into areas that are today used for grazing”. I don’t see skyrocketing cropland yields happening with all the news about failed harvests and drought caused by climate change lately. The authors state that human diets are the strongest influence on our options. They continue that vegan and vegetarians diets allow us to choose from many more options and that these are “associated with only half the cropland demand, grazing intensity and overall biomass harvest of comparable meat-based human diets”.
We won’t be able to keep up our current level of meat consumption with further human population growth and climate change. *You* are responsible for the preservation of our planet, so start lowering your meat consumption drastically or become vegetarian or vegan. Do what must be done, even if it is inconvenient for you! Personally, I still like meat, fish and cheese, but I haven’t cooked meat in years and probably eat less than a two kilos of fish in year. I do still eat meat a few days a month when others cook for me, however. I will strive to lower my consumption of meat, fish and cheese further.