Most of us rely on cows for dietary staples like milk, dairy products, and beef.
But the world’s 1.5 billion or so cows are also responsible for a huge portion of the world’s greenhouse gas emissions, namely methane — a gas that’s 30 times more powerful than carbon dioxide at trapping heat within Earth’s atmosphere.
In fact, estimates for the amount of methane the average dairy cow produces in a day range from 26 gallons to 132 gallons. That’s an amount comparable to the amount of pollution a car expels in one day, and it’s prompting many scientists and environmentalists to research ways to reduce the amount of methane that cows emit.
In Australia, this research is manifesting itself in the form of the country’s above-ground dairy effluent storage tank.
According to a Feb. 28 Australian Broadcasting Corporation (ABC) Rural article, this tank measures 40 meters in diameter and is part of a Tasmanian Institute of Agriculture (TIA) study aimed at finding whether or not shorter dairy effluent — or in less polite terms, cow poop — storage times will lower methane emissions.
According to ABC Rural, the above ground effluent storage tank will collect rainwater in addition to the liquid waste it stores, which will be used as fertilizer. The TIA will carefully measure the amounts of methane that come from the tank’s contents.
A trafficable solids trap and weeping wall have been installed to separate solids and divert them into a sump pump that pumps the waste into the tank, according to Rachel Brown of Dairy Tasmania, the organization collaborating with the TIA on this research. The liquids from the storage tank will then be pumped throughout the farm’s irrigation system as a fertilizer for the grass that feeds its cows, creating a more sustainable agricultural system.
These above ground effluent storage tanks are already in widespread use throughout Australia’s neighbor country, New Zealand, according to Dairy Tasmania.