I know that cutting down trees to make way for agriculture is a big factor in the global decline of the environment. And I know the problem with burning fossil fuel is that it is releasing CO2 stored in ground from millions of years ago. What I don’t understand is how a cow or a chicken contributes new greenhouse emissions?
fyi I don’t really eat beef and are trying to be flexitarian so this isn’t about defending eating meat.
In: Biology
Earth is not a closed system. It receives, at the very least, constant energy input from the Sun. This energy input allows for chemical and biochemical processes to occur (e.g. plants growing), and these processes in turn allow for the chemical synthesis of various things – such as the molecules comprising greenhouse gases – to occur as well.
Consider this, for example, happening on any given day:
* Sunlight provides energy for plants to grow, and these plants convert various available chemicals into complex molecules and compounds
* Animals eat these plants, breaking their complex bits into simpler constiuents that may include the things that make up greenhouse gases
* The animals excrete or die, either directly releasing the converted chemicals or being decomposed by microorganisms which then excrete them
This is a simplistic portrayal, but I think it may make the point.
Three ways: first is the straightforward way. That carbon that they are eating used to be in plants, it no longer is. They fart it our and breath it out at CO2 in quite large quantities. They take away a capture system and turn the captured carbon into another form very inefficiently
Second is measurement way, CH4 (prominent in cow farts) is 20x the greenhouse gas that CO2 is in terms of how much infra red radiation it blocks. Meaning how much it impacts global warming. Certain measures (but not all) count it accordingly, so 20x bonus for cow farts basically in some counts. Some do straight CO2 and will not do this, most ones that say GHG will.
Thirdly the indirect/manufacturing costs. Its just a huge facility with a lot of heating/cooling needs (depending on the time) with a ton of transportation, heavy machinery and processing. Farms are busy places with a lot of trucks and tractors, and there are a lot of them. Depending on the animal/crop greenhouses may also be needed which are again energy intensive. There are also just a lot of them compared to basically any other industry. We eat a lot of food.
Do those make sense?
(The closed loop bit is mostly true but doesn’t account for chemical transformations from straight carbon (or hydrocarbons) reacted with oxygen to make CO2)
Methane. If you burn a forest down you release mostly CO². Cows can convert plant matter to a lot of Methane wich is a much worse greenhouse gas.
We currently research on how to feed them in a way that makes them less “gassy”
Other than the greenhouse gases meat production also uses up a lot of water and agricultural space. If you’d only eat plants instead of growing plants and feeding them to cattle you could feed more people, or have more natural forests wich store a lot of carbon
Carbon in the atmosphere is the problem. It can take hundreds or even thousands of years for that carbon to return to the earth.
Although you can consider it a “closed” system in the sense of the amount of total carbon available, commercial agriculture and raising cows and chickens are not natural in the sense that human intervention and innovation has allowed for a great deal of intensification that could otherwise not happen in nature.
A poor analogy might be a car engine, where if you run it at a constant 2000RPM, it would run as long as you had fuel feeding it. But try running the same engine at 7500RPM and most engines would start to overheat very quickly as the cooling system just could not cope.
Just like a car engine, there is a range where the systems can still find an equilibrium, but past a certain point, there is no equilibrium and the excess temperatures lead to failures in the engine itself.
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