Introduction
If global food waste was a country it would be the third-largest emitter of greenhouse gases in the world. Every year, 1.3 gigatons (1.3 billion tons) of food is wasted, emitting 3.3 gigatons of CO2, without including the emission of land use for cultivation. Thus, global food consumption plays a major role for our future climate.

Why does food emit CO2?
Slightly simplified, there are three things at play.

1. To get food it takes up geographical space. In that place, we build fields, plantations, stables, etc. The more food we have to produce, the more space it requires. In the early days of mankind, almost the entire world was covered by wild nature, but as we cultivate more land, we increasingly cut down trees and other wild nature. This nature mitigates carbon dioxide through photosynthesis and when it's cut down, more CO2 will be emitted into the atmosphere.
   

2. We use a lot of fossil fuels in agriculture. We drive heavy machinery, heat stables, transport food over long distances in large trucks, keep food cooled with electricity from coal-fired power plants, and much more.
   

3. Agriculture emits a lot of other harmful greenhouse gases. Animals such as cows and pigs emit e.g. methane gas, a gas that is 25x worse than carbon dioxide. In addition, fertilizers emit nitrous oxide, which is about 300x worse than CO2.
   

Why is meat worse than vegetables?
For two reasons:

1. You waste a lot of food. To produce 1 kg. of meat, the animal must be fed many kilos of grain or other types of food. On average, 1 kg. of meat emits about 20x more CO2 than 1 kg. of vegetables. In addition, it also takes up 100x more land compared to growing vegetables. About 80% of the world's agricultural land is used for animal husbandry. But if the world switched to a plant-based diet, we could feed about 3.6x as many people - or emit 3.6x less CO2 with the number of people we are in the world currently.
   

2. Methane. In particular, cows burps a lot of methane, but most animals' feces cause methane emissions, which is what we capture with our project in Sichuan. Globally, methane ends up being a big deal for the climate, as methane gas is 25x times more potent than greenhouse gases, which means it heats the earth 25x more than carbon dioxide.
   

Is organic agriculture worse than conventional agriculture?
This discussion is well-debated. Some claim that organic farming emits more CO2, as it takes up more space. As explained in the section “Why does food emit CO2?”, the space we use in agriculture is ultimately space that is not used for forestation.

However, this is a somewhat simplistic explanation, and there are many factors in organic farming that come into play, such as better biodiversity, fewer emissions from fertilizers, and so on.

In the end, it depends on the individual type of food, and some people will argue that conventional agriculture is worse, while others argue the opposite. We do not believe that the difference is large enough to be particularly important. As a result, we simply choose to support organic farming for the many positive side benefits it has for the environment.

Is locally better than imported?
Generally speaking, transport does not account for a very large part of the CO2 emissions from food, meaning that local- vs. imported food does not play a large role. But the answer is, unfortunately, maybe.

If we are talking potatoes in season, then it is better to buy locally as you save CO2 on transportation. If, on the other hand, you are talking about tomatoes in the winter, it is far better to buy tomatoes imported from a naturally warm place than Danish tomatoes from a heated greenhouse.

What about food in season?
If you buy food in season in your particular country, you can be sure that you are doing the climate a favour as you avoid transportation. In addition, a lot of energy isn't wasted on heating a greenhouse somewhere. It probably does not make a huge difference like deselecting aerial transport when going on vacation or the like, but it will definitely benefit your climate footprint.

The reason we do not ask about it in our test is that it is difficult to find a common definition of what it means to “eat in season” and due to the fact that it doesn’t make a huge difference.

Is all meat just as bad?
No. Not at all. Beef emits 4.5x as much CO2 as pork, while chicken and fish emit only half as much as pork. So if you want to start eating a little less meat, start cutting out beef.