India, Oct. 6 -- Rotting food waste is causing up to 10 per cent of total global greenhouse gas emissions - five times more than the entire aviation sector, the UN's environment agency warned this week.

If overlooked, food waste represents a key driver of the climate crisis, according the UN Environment Programme (UNEP), but tools are already being deployed to tackle that threat, from black soldier flies to empowering waste pickers across the world.

Food waste encompasses everything from unfinished meals to spoiled crops (that's food that is lost after harvest and before reaching stores).

When organic matter such as uneaten food is buried in landfills and deprived of oxygen, it interacts with micro-organisms to produce methane.

Greenh...