Every year in the UK, an estimated 10 million tonnes of food waste winds up in landfills. That’s a lot!
It takes up unnecessary space, adds costs, and releases methane into the atmosphere. Because methane can be used for cooking, generating electricity and heat, and as a vehicle fuel, that's also a big waste.
We saw large-scale anaerobic digesters were doing a good job of extracting useful by-products from food waste but there are limits to this size, scale, and use.
To make the process more local, accessible and transferable, we decided to demonstrate it at micro-scale in Central London. We figure, if we can make this work here we can make it work anywhere!
Methane is a greenhouse gas 20-30 times more potent than CO2. Our solar system shows some striking examples of greenhouse gas activity. Take Venus, the hottest planet in the Solar System. With a global temperature of 462ºC, the surface of Venus is hot enough to melt lead and its atmospheric pressure is 92 times greater than Earth’s!
When sunlight hits the ground, heat is radiated back into space but carbon dioxide in the atmosphere traps much of it around the planet.
Scientists think that Venus used to be more similar to Earth, with lower temperatures and even liquid water on the surface. At some point, billions of years ago, the planet started to heat up and all the water evaporated into the atmosphere.
Eventually, Venus became so hot that carbon trapped in rocks sublimated into the atmosphere and mixed with oxygen to form even more carbon dioxide. So today we have a carbon dioxide atmosphere on Venus.
At the other extreme, Titan features vast methane seas at temperatures around minus 180ºC. Discovered in 1665, Titan is Saturn's largest moon. The green and red hues in this NASA image show where methane in the atmosphere is absorbing light.
Back on Earth, methane (produced extensively by the livestock industry) accounts for only 14% of global emissions but traps up to 100x more heat than CO2 over 5-years. Capturing these emissions as biogas to replace fossil fuel is key to tackling climate change.