Greenhouse gases dominate the discussion about climate change. The production of one liter of cow's milk generates as much CO2 as a city commuter emits daily in a car.

One cup (250ml) of cow's milk emits a global average of 787g of carbon dioxide.

This means that cow's milk produces about three times as many greenhouse gases as all its alternatives.

Land use also counts in the life cycle assessment. But here, too, cow's milk brings up the rear. Why? Basically, animal-based foods always consume more land because not only does the feed have to be grown, but the animals also have to be kept.

This only applies to milk from factory farming. A cow whose manure is used for fertilizer and which grazes on a meadow can certainly do something to improve the climate: As it wanders over the pastures, it promotes humus buildup - and that binds carbon. So it depends on what kind of milk you buy.

Almond and rice drinks are clearly ahead of cow's milk.

If you're concerned about the environment, it's best to use oat milk. It has the least impact on the environment. In addition, oats are often grown locally, which reduces transport distances. Another plus: Because the grain is quite resistant, less spraying is done on the fields.

With that, you could take a shower 703 times for eight minutes.

In addition, an area of land the size of 652 square meters will be used for this purpose - that's about the size of two tennis courts.

For the daily glass of milk, 229 kilograms of greenhouse gases are emitted - in a car, you could drive 941 kilometers with it, i.e. roughly from Indianapolis to Washington D.C..

If you switch from cow's milk to oat milk, the most ecological alternative, you could save up to 0.64 kilograms of CO2 every day. That's three percent measured against the CO2 we consume every day.

If we drink a cup of coffee with oat milk every day, it is more harmful to the climate than a glass of cow's milk. This is because coffee has a significantly worse climate footprint over the entire production cycle.