Environmental impact of meat consumption

For the majority of the world's population, insects are an important part of their diet. Countless varieties of beetles, their larvae, crickets, ants or locusts are consumed in Asia, Africa and the Americas.
People of the western hemisphere however have been reluctant to add these creatures to their meals, though casu marzu can serve as a noteable exception for entomophagy in Europe.

In the face of a changing climate and a world population that has surpassed 7 billion, it seems a necessity to consider insects as protein sources in addition to meat.
In fact, there are already some companies that sell snacks made from insects. What is now needed is an increase of production and marketing of these foods.

The point is, cattle and pigs, our sources of red meat, all emit methane when they digest what they are fed. Methane acts as a greenhouse gas and is about 20 times as potent as carbon dioxide.
These emissions can in part be mitigated by choosing the right food for the livestock in order to influence digestion processes in their guts; however, farmers still need to feed a significant multiple of what they will end up with as actual meat.

An often-quoted number is the ratio of 54:1 in energy input required to produce a particular output of protein for cattle, whereas for insects, the number is as low as 4:1.
What this means is, you need fifty times less energy to produce protein from cattle than you need for the same amount of meat from cattle.
Costs associated with insect meat are therefore significantly lower, as resources needed to breed the tiny creatures like water, food crops and energy for lighting can be used more economically.

Another more recent report linking food production and energy consumption can be found here.
Including insects as sources of animal protein has implications for land use, too. Meal worms for example can be kept in boxes that allow for higher density in usable protein per cubic meter than conventional livestock. This results in more efficient transport, lowering greenhouse gas emissions even further, as production can be optimized for smaller-scale, localized shops.

To give you an idea, see this site with pictures and a very comprehensive list of edible insects at this page.

Of course, we should be aware that reducing our overall meat consumption is a viable option. Some alternatives based on soy sound pretty interesting.