Growing mushrooms is a unique blend of recycling, science and efficacy. This powerful combination makes them one of the most sustainably produced foods in the United States.
Mushroom growers in the United States are known as the ”ultimate recyclers“ for their ability to convert byproducts and waste from other sectors of agriculture into the compost or medium used to grow mushrooms. Because of this recycling of other agricultural crops and byproducts, mushroom farms have a smaller environmental footprint than almost any other farms.
In fact, when you go into the store and see white or brown “button” mushrooms, you are looking at an incredibly efficient food: Today’s growers use smart management and production practices that use less than 2 gallons of water to produce one pound of button mushrooms – that’s about 32 (8 oz) glasses of water to grow, harvest, and process an entire pound of mushrooms, compared with an average of 50 gallons of water per pound of other fresh produce items. Finding ways to control water usage and recycle the water that is available means mushroom growers can minimize how much of it they need and likewise minimize the impact their farms have on surrounding environments.
Similarly, mushrooms are a fairly low-energy footprint crop. Producing one pound of button mushrooms takes 1.0 kilowatt hour (kwh) of electricity. This is the same amount of energy (1 kwh) as it takes to run a coffeemaker for one hour each day! Because of the way mushrooms are grown, being smart about energy use is good for production AND good for the environment.
Growing that one pound of mushrooms is so efficient, in fact, that it generates just 0.7 pounds of CO2 equivalents. This means if you added up all the emissions of carbon dioxide (CO2, a greenhouse gas) from producing that one pound of button mushrooms – from the compost recipe all the way through to what you purchase in the store – it is the equivalent of just 0.7 pounds of CO2. To give some perspective of how small a carbon footprint that is, using one gallon of fuel in the U.S. emits nearly 20 pounds of CO2.
Mushrooms are grown year-round, across the nation, and don’t require much land. On average, one square foot of space in a mushroom bed can produce 6.55 pounds of mushrooms. One square foot is 144 square inches, or 4.5 red bricks in a patio – that’s a lot of production power in a small space!
In fact, one acre of land can produce 1 million pounds of mushrooms. In 2017-18, mushroom growers sold 917 million pounds of Agaricus mushrooms. Put another way, one acre of land can produce enough mushrooms to fill the length of nearly 4,700 football stadiums. Even more, 917 million pounds of mushrooms is enough to circle the circumference of the globe mushroom cap to mushroom cap 19 times!
By any measure of water and energy inputs, and the low CO2 emissions, mushrooms are a nutritious food that have a very small environmental footprint. More than being the ‘ultimate recyclers,’ mushroom growers are providing a sustainable, smart food source for a growing world population.
How Mushrooms Stack Up:
As consumers look to make food decisions that take environmental impacts and carbon footprint into account, mushrooms are a choice that everyone can feel good about.
The carbon footprint of mushrooms is much smaller than most other sources of proteins and vegetables. Not only are mushrooms delicious and nutritious, they are also a sustainable food consumers can feel good about purchasing.
Mushrooms have 0.5 Kilograms (kg) of CO2 per pound of food consumed. In comparison, chicken has 3.1 kg CO2 per pound consumed. Pork has 5.5 kg CO2 per pound consumed. Salmon has 5.4 kg CO2 per pound consumed. Cheese is at 6.1 kg CO2 per pound consumed. Eggs are 2.2 kg CO2 per pound consumed. Broccoli is at 0.9 kg CO2 per pound consumed. And Tofu is at 0.9 kg CO2 per pound consumed.
A serving of mushrooms is just 0.08 kg of CO2 emissions – only lentils have a lower per serving CO2 emission level.
About this overview:
The narrative contained in this report uses The Mushroom Sustainability Story: Water, energy, and climate environmental metrics by SureHarvest (2017) as a foundational document for the speaking points. The SureHarvest report is the result of a two-year environmental footprint assessment initiative documenting mushroom production in 21 operations through the lens of environmental metrics. This work included a focus on water and energy consumption as well as potential impacts on climate change (through generation of CO2 equivalents) and reflects approximately one-third of U.S. mushroom production.