The Green Christmas Ham

A green Christmas ham sounds like a memorable Christmas for all the wrong reasons. Yet the Australian pig industry prides itself in the greenness of its hams and all of its pork.

Clearly a green ham is indicative of its environmental impact as opposed to just plain nasty pork. Understanding how a ham can indeed be green requires just a brief overview of how a piggery is laid out:

piggery
Where the waste goes. It all ends up in a big pond.

Essentially all the waste from the stalls either flows out the front (as above) or drains through grates in the stalls and flows into settling ponds. The solids/liquids are then spread back onto the field as fertiliser.

However, as innocuous as these ponds may seem (they aren’t very innocuous), they contribute around 70% of the greenhouse gas (GHG) emissions from a piggery, primarily as methane released from the surface. Now the Australian pork industry accounts for only 0.4% of the Australian national GHG emissions compared to – beef – 11.2%, sheep – 3.4%, and dairy – 2.7%.

Yet because these ponds account for so much of on farm GHG emissions they represent an easy area to target to reduce the carbon footprint of the farm. All of the methane gas is captured by an impermeable membrane (read: sheet of plastic) stretched out over the surface. The gas bubbles up and is directed towards storage tanks. The next stage of the process of fantastic.

The stored methane is then burnt in electricity generation, enough to power not only the entire farm but 62 other homes! The energy generation is mainly used on farm to keep little piglets warm and general use in pumps and lighting. This technique of capturing biogas and using it for energy generation can reduce the GHG emissions by up to 80%.

Talk about a green ham.

Leave a Reply