Garbage keeps piling up. According to a recent World Bank report, the world produces some 1.3 billion tons of solid waste each year — and that number is set to double by 2025. Here in the developed world, the average person throws away about 2.6 pounds of trash each day.

But what's actually in that trash heap? This not-so-appetizing chart from the EPA breaks down American garbage. There's a lot of paper, a lot of food, and a lot of, uh... yard trimmings:

One of the most notable bits in this slimy mess is "food waste." That includes uneaten food and preparation scraps from farms, processors, grocery stores, restaurants and homes. The amount of tossed-out food has risen rapidly in the past three decades — by one estimate some 40 percent of all food that's grown in the United States never gets eaten.

And there's a real cost here. A 2011 study by McKinsey estimated that tossed-out food scraps represent a loss of about $252 billion around the world. Agriculture, after all, is an intensive process that requires plenty of oil and water — two resources that are already in limited supply. Plus, food that rots in landfills tends to decompose into methane, a potent greenhouse gas that's helping to warm the planet.

Interestingly, various companies are trying to develop technology to reduce all the food we throw in the trash. Jonathan Bloom, who runs the fascinating blog, explains:

Enhanced interest has trickled into technology. Tufts University professor Fiorenzo Omenetto is developing edible patches to be placed on fresh foods that detect bacteria levels. These patches communicate to smartphones whether food is still good to eat. These “food tattoos” could be available in three to five years.

At the Massachusetts Institute of Technology, researchers have developed sensors to detect a fruit’s ripeness. These ethylene sensors would be placed on boxes of fruit to let grocers know when to put fast-ripening items on sale.

LeanPath, a technology company that tracks waste, lets kitchen staff in universities, hospitals and elsewhere track the amount and causes of food loss so it can be minimized.

Some states like Massachusetts, meanwhile, are trying to divert commercial food waste out of their landfills in order to tamp down on heat-trapping methane emissions. Still, that's just a small start. As these charts from Derek Thompson looking at global trash show, the nearly half of the planet's garbage is organic matter, and the vast bulk of that ends up rotting in landfills. (Less than 2 percent of the world's garbage is recycled or composted.) Which means there's a lot of this:

(Flickr photo credit:Yunchung Lee)

Anyway, now back to your regularly scheduled lunch break!