One point three billion metric tons - that's how much food that we waste each year.

Not an easy number to wrap one's head around. Try to imagine 143,000 Eiffel Towers stacked one on top of the other-together they'd weigh around 1.3 billion tons. The sheer scale of the number makes it practically impossible to grasp, no matter how you come at it.

Rendering the figure all the more unfathomable is the fact that alongside this massive wastage of food, 840 million people experience chronic hunger on a daily basis. Many millions more suffer from "silent hunger" - malnutrition and micronutrient deficiencies.

For the more economically minded, here's another number: the economic cost of food wastage runs around $750 billion per annum. This is expressed in producer prices; if we were to consider retail prices and the wider impacts on the environment including climate change, the figure would be far higher.

In times of austerity, it's difficult to understand how a hemorrhage of money like this could go neglected. Yet it does. In fact, in some places, the volume of food wastage is rising.

Now a new report by the UN Food and Agriculture Organization, to be spotlighted at the Green Growth Forum this week in Copenhagen, has shed light on another troubling aspect of the problem: the negative consequences for the environment and the natural resources we rely on for our survival.

When food is lost or wasted, the energy, land and water resources that went into producing it are also squandered -while at the same time large amounts of greenhouse gases are released into the atmosphere during production, processing, and cooking.