How can you measure the effects of a worm farm?

The main point of a worm farm is to divert food scraps away from landfill, where they decompose in anaerobic conditions (that is, without any air), and so produce methane which is a gas about 20 times more harmful to global warming than carbon dioxide.

You can measure the effects by the amount of food waste you still throw away compared to the amount your worms eat. A worm will eat its own body weight in one day, so at the start, with 1000 worms, you can only feed about quarter of a pound (125 grams) of food scraps per day. Later, if your worm farm increases to 20,000 worms, you can feed much more.

And a side effect of your worm farm is, of course, the worm castings and urine, which make Excellent plant food for your garden.