Here’s a project for Earth Day. Can you figure out how much food you throw away?

The town of Winslow can — 400 to 800 pounds a year, all of which the town pays to have stuffed into a landfill, where it decomposes, releasing greenhouse gases into the atmosphere.

Until now. This week Winslow began accepting food waste at a drop-off site at the town library; from there, it will go to Agri-Cycle in Exeter, where it will be turned into energy.

It may only be one small town, but Winslow is on to something big. It doesn’t get the attention of coal-fired power plants or gas-guzzling vehicles, but food waste is one of the largest contributors to greenhouse-gas emissions.

As much as 40% of the food produced for human consumption is being discarded along the supply chain — from being left to rot in the field to being tossed into your home garbage uneaten.

It’s bad enough that all that is thrown away when so many others struggle daily to get the food they need. But that’s hardly the only problem.

When a piece of food is wasted, so is all the energy used to grow, process, ship and store it. And once food waste is in the ground, it gives off methane, one of the leading drivers of climate change.

As a result, food waste is just behind road transport when it comes to the emissions. If it was its own country, food waste would be the third-largest emitter of greenhouse gases, behind China and the U.S.

Simply put, there’s no way to address the climate crisis without first looking at how much food we throw away.

U.S. Rep. Chellie Pingree, D-1st District, has been a leader on this issue for some time. In 2018, she formed the Bipartisan Food Recovery Caucus, and she secured a number of food waste initiatives in 2018 Farm Bill.

She also has introduced a series of bills aimed at decreasing waste further; they were included in the recommendations made in the report from the Select Committee on the Climate Crisis.

One of those is the School Food Recovery Act, and it shows just how big the problem is: Schools waste about 530,000 tons of food a year, contributing about 1.9 metric tons of greenhouse gases. Just a 3% reduction nationwide, Pingree’s bill says, would be like taking 12,400 passenger vehicles off the road.

Of course, it’s not just schools that produce waste. Hannaford Supermarkets said this week that it would no longer send food waste from its stores to landfills. Instead, they are managing their supply chain better to avoid waste and sending what’s left to food pantries, farms and a trash-to-energy company.

Other large producers of waste should follow Hannaford’s lead, just as other municipalities should look into programs like Winslow’s.

There are also volunteers like the Central Maine Gleaners Group who pick up surplus food from farms, hospitals and other sources for redistribution — they are always looking for help.

Individual households, too, can do a lot to cut back on food waste through good habits at home, such as composting.

This Earth Day, everyone should take it upon themselves to think about how much food is wasted — by their households, by their governments and institutions, and by the businesses they frequent — and how much that waste takes from our health and well-being.

It is more than most of us realize, and it should drive us all to change the wasteful way we do things.