Vegetarianism reduces carbon emissions

The argument

Carbon footprint is defined as the amount of greenhouse gases (primarily carbon dioxide) that are released into the atmosphere as a result of a particular human activity. Carbon emissions from agriculture stem from soil management, energy use, manure, and more. Currently, emissions from food "contribute 19%-29% of global anthropogenic greenhouse gas emissions." Meanwhile, total emissions from global livestock contribute around 14.5% of global anthropogenic greenhouse gas emissions. This means that more than half of all food emissions result from animal products. Livestock not only take more energy to produce, which contributes to the high amount of carbon emissions, but animals such as cattle also release methane. Emissions from animal products can effectively be cut down by reducing or altogether eliminating animal products from diet. Plants and vegetables have a much smaller carbon footprint. The average vegetarian diet produces "the equivalent of about 8.4 pounds of carbon dioxide per day," which is half as much as that of "high-meat" diets (15.8 pounds of carbon dioxide per day). By reducing or eliminating animal-based diets, carbon emissions can be drastically reduced, which would serve to better our environment in slowing down global warming and climate change.

Premises

Counter-arguments

The headline derivation does not hold. The two figures cited come from different studies with different accounting boundaries: the food-system range covers the whole chain from land conversion through retail and waste, while the livestock figure is a separate estimate built on its own methodology. Subtracting one from the other to conclude that animal products account for more than half of food emissions treats them as commensurable when they are not, and the range itself — a spread of ten percentage points — signals how unsettled the underlying accounting is. The more consequential gap is between vegetarianism and the emissions being counted. Most of livestock's climate impact comes from ruminants, and dairy is a ruminant product: a vegetarian diet built on milk, cheese and butter retains a substantial share of the methane the argument is trying to eliminate. Cheese in particular sits near the top of the emissions ranking for common foods. The case as constructed is a strong argument for reducing beef and dairy, and only a weaker one for vegetarianism as such — the position it is offered to support. The daily comparison is also softer than it looks. Dietary-footprint studies rank people by self-reported intake in a particular country's food system, so the gap between the vegetarian and high-meat groups absorbs correlated differences in income, transport, household size and total calories, and the figures do not transfer to food systems with different production methods, grid mixes or transport distances. Pasture-raised ruminants on land unsuitable for crops also occupy a place in the ledger the argument does not address. Finally, the question asks for pros and cons. Even a fully established emissions benefit is one entry, and the argument makes no attempt to weigh it against what sits in the other column.

Rejecting the premises

[Rejecting P1] The food-system range and the livestock estimate come from different studies with different accounting boundaries, so subtracting one from the other to derive 'more than half of food emissions' treats incommensurable figures as comparable — and the ten-point spread in the range itself indicates how unsettled the underlying accounting is. [Rejecting P2] The comparison is between diets rather than between the vegetarian option and its alternatives on equal terms: dairy is a ruminant product carrying much of the methane the argument targets, and cheese ranks near the top of common foods by emissions, so the evidence supports reducing beef and dairy rather than vegetarianism specifically; dietary-footprint figures also absorb correlated differences in income, calories and household composition and do not transfer across food systems. [Rejecting C] Even granting the emissions benefit, the question asks for pros and cons, and establishing one entry in the first column does not weigh it against what sits in the second.