Today, a third of all the food produced in the world goes to waste. That’s equal to about 1.3 billion tons of fruits, vegetables, meat, dairy, seafood, and grains that go bad on the farm, get lost or spoiled during distribution, or are thrown away in grocery stores, restaurants, and home kitchens. It’s also enough food to feed every undernourished person on the planet several times over.

But wasted food isn’t just a social or humanitarian concern—it’s an environmental one. When we waste food, we also waste all the energy and water it takes to grow, harvest, transport, and package it. And if food goes to the landfill and rots, it produces methane—a greenhouse gas even more potent than carbon dioxide. Food waste creates about 8% of all human-caused greenhouse gas emissions. In the US alone, the production of lost or wasted food generates the equivalent of 43 million cars’ worth of greenhouse gas emissions.

As the world’s population continues to grow, our challenge should not be how to grow more food, but to feed more people while wasting less of what we already produce. Thankfully, there are plenty of actions we can take at the consumer level to make a significant difference. From delivering leftovers to those in need of freezing food, shopping smarter, and composting to keep inedible scraps out of landfills, we can all take small steps to curb our emissions.

Plan ahead and buy only what you need. Going to the store without a plan or on an empty stomach can lead to buying more than we need. To keep your kitchen on track, try to eat leftovers, think of meals you can eat out, and avoid unnecessary purchases by planning your grocery list ahead of time.

Use your freezer. While there are plenty of benefits to eating fresh food, frozen foods can be just as nutritious. They also stay edible for much longer. A lot of seafood, for example, is frozen before it reaches your supermarket and then thawed and put on display. That means it will only stay fresh for a few days. By buying frozen seafood, you can extend the shelf life of the product considerably.

Be creative with leftovers. Before you shop, use the food you already have. Websites like Big Oven, Supercook, and MyFridgeFood allow you to search for recipes based on ingredients already in your kitchen. You can also use apps like Epicurious and Allrecipes to make the most of what’s in your fridge and pantry.

Blend, bake or boil. Fruits and vegetables that are beyond ripe might not look pretty, but that doesn’t mean they can’t still taste delicious in recipes. Try using your wilting, browning, or imperfect produce to make sweet smoothies, bread, jams, sauces, or soup stocks.

Talk it up. Preventing food waste is the most effective way to shrink its impact on the planet. If we avoid producing the food we don’t eat, we can save the land, water, and energy that would have been used to make it. And awareness is a good first step: according to ReFED, educating consumers about food waste could prevent 2.3 million tons of greenhouse gas emissions.waste.)

The water wastage alone would be the equivalent of the entire annual flow of the Volga—Europe’s largest river—according to a UN report. The energy that goes into the production, harvesting, transporting, and packaging of that wasted food, meanwhile, generates more than 3.3 billion metric tons of carbon dioxide. If food waste were a country, it would be the world’s third largest emitter of greenhouse gases, behind the U.S. and China.

We tend to take our food for granted in the developed world. Since food is so plentiful, we aren’t aware of the tremendous amount that’s wasted and the impact that has on world hunger, political stability, the environment, and climate change. Yet when it comes to looking for ways to curb greenhouse gas emissions, food wastage is a relatively easy fix—the low-hanging fruit, so to speak—and it is literally rotting on our tables. It doesn’t require any new technology, just more efficient use of what we already have.

We can all take small steps that will accumulate to make a meaningful difference. Let’s buy just the food we need so we throw away less. Let’s accept that produce can be top quality and delicious even if it has a slight imperfection in appearance. Let’s bring meals home that we don’t finish in restaurants. Small changes will yield big results.