PRODUCT NAME Trappist Dairy and Kowloon Dairy bottled milk

PRICE HK$12 for 2 bottles. HK$1 bottle deposit.

PRODUCT RATING Nothing beats the taste of fresh milk. You can tell the fresh milk (silver) apart from the reconstituted milk (green) by the color of the foil cap on the bottle. Some milk sold in cartons is Ultra Heat Treated (UHT) which changes taste, smell and affects its nutritional value. The minor inconvenience of having to rinse and return the bottles is pretty easy to get used to.

GREEN RATING Light Green. Dairy is very environmentally unfriendly, putting milk in a re-usable glass bottle as opposed to disposable paper carton may make it slightly less so.

AVAILABLE AT Most major convenience stores (7-11, OK) and supermarkets (Park & Shop, Wellcome).

First, lets start with two confessions: (1) buying milk in a glass bottle is probably about as green as driving a SUV with the air conditioning turned off in order to save energy, (2) we don’t possess the mathematical ability to verify that re-useable glass bottles are more environmentally friendly than disposable paper cartons. What we do know is that they won’t end up in the landfill after one use.

Although I know that milk is very environmentally unfriendly, I still have difficulty completely eliminating milk and cheese from my diet. I have however reduced my milk consumption by about 50%, by replacing it with soya milk.

Conventional dairy farming depletes nutrients in the ground and uses huge quantities of fertilisers — fertilisers account for roughly 1% of the world’s total energy consumption. And the methane cows emit in the atmosphere is over 20x times more damaging than CO2. Cadbury’s did a study of the carbon footprint of its chocolate bars and found that although milk only constitutes 1/3 of the weight of the ingredients, it was responsible for 2/3’s of the total carbon footprint. That is quite astonishing when you consider that the total footprint includes packaging, processing, transportation and obviously cocoa (which is itself not an environmentally friendly crop to say the least).

The primary benefit of the glass bottle is that it is re-usable. The drawbacks from an environmental perspective are that (a) it weighs more than a paper carton and hence requires more fuel to transport, (b) it needs to be cleaned and sterilized with high pressure, hot water. I believe that even with these drawbacks, it should still be better than cutting down trees to make paper cartons and then throwing the cartons into the landfill after a single use.

The best thing we can probably do to reduce our carbon footprint in this respect is to replace cow’s milk with organic soya, oat, rice or almond milk, although there aren’t any conclusive evaluations to back this up yet. When you take into account the impact of cattle feed – a liter of dairy milk may use more soya in production than a liter of soya milk. Having said that, as the Guardian points out, non-organic soya has its own problems with vast tracks of rainforest cleared to grow soya as a monoculture crop, tons of synthetic fertilizers and pesticides applied, and processing that often uses hexane, a neurotoxin petrochemical solvent.

Switching to organic soya milk or buying dairy milk in a glass bottle may seem small and inconsequential compared to the challenge of climate change, but it is the sum of the decisions we make collectively on a daily basis that will ultimately determine fate of our planet. Politicians and business leaders follow our lead as citizens and consumers, not vice versa.