Author Kyle Simpson is the founder of Local Loop Farms, a startup turning food waste into fresh food through integrated ecosystems inspired by nature. To get more great content from the Urban Vertical Project and partners like Kyle, sign up here!

Kyle is going to breakdown, category by category, how switching to vertical farming could cut 20% of our global greenhouse gas emissions.

You’ve probably heard before that the Earth’s population will have an additional billion people within ten years, 2.5 billion over the next 35 years, and that nearly two-thirds of this global population is expected to live in a city during this time.[1, 2] You may have even heard that feeding these new generations will require humanity to increase food production by 70% over our current levels of production.[3]

The catch, however, is that food production and consumption already accounts for 19% to 29% of global greenhouse gas (GHG) emissions, larger than emissions from the energy or transportation sectors.[4, 5]





Higher temperatures will decrease crop yields, water access, food safety, and increase levels of social unrest as people struggle for basic necessities — making the problem of producing more food than we currently do even more difficult.[4, 6 – 8] The economic cost of all of this is equivalent to 3.3 trillion dollars annually from the global food industry alone. Ultimately we need to be doing more with less, and that’s where vertical farming shines.

Land cover change accounts for almost 13% of global GHG emissions and the majority of this land cover change is for agriculture.[4, 9] Soilless vertical farming allows for us to create our own landscapes. Instead of converting more and more of the natural landscape to agriculture, non-arable land, rooftops, and even the sides of buildings become productive spaces put to use.

Food loss and waste is the second largest emitter, accounting for another 10% of global emissions.[4] Indirect emissions account for the energy expended to produce the food that is going to waste, implying that all of the hard work and effort that went into getting the food to you is literally dumped in a landfill. A waste free society might be utopian, but there are a few companies out there who are turning food waste into fertilizer, rather than another landfill pile — for instance, check out Re-Nuble!

The third largest emitter from the food industry is nitrous oxide (N2O) from over application of fertilizer. This accounts for another to 5% of global GHG emissions.[4] Although soilless methods still use the same fertilizers, they use the fertilizers and water in a recirculating loop – allowing precise control and recapture of valuable resources and preventing over-application (see the disastrous consequences here). Some vertical farms, like Aerofarms, claim a 50% decrease in fertilizer use and a 95% decrease in the amount of water used, compared to conventional field agriculture. This increased water efficiency also means decreased runoff contributing to deadzones like the one located beneath the United States in the Gulf of Mexico.[10]

Biomass burning is still used today by many countries around the world as a method of clearing and maintaining land for agricultural use, accounting for approximately 1.5% of emissions. The burning of agricultural fields is commonly used for grass, weed, litter, and sometimes pests — problems completely avoided through vertical farming and methods of alternative pest control.

Fertilizer manufacture is the 7th largest contributor of global GHG emissions with a little more than 1% of emissions. Conventional fertilizer manufacture generally uses natural gas or coal as a base ingredient, but there are alternatives like aquaponics, anaerobic digesters, and compost that avoid the fossil fuel use.[4] Vertical farms for the most part are still limited to conventionally manufactured fertilizers, but the resource efficiency of vertical farming implies they could grow an additional 67% more food using the same fertilizer inputs. By that calculation, we could nearly reach the target of 70% increase in food production using the same resources, or we could produce what we need today using 40% less fertilizer.

Refrigeration ranks 8th, in global GHG emissions, accounting for 1% to 4%.[12] Most of this is from countries that rely heavily on imported food. The local food production that vertical farming allows means less refrigeration, and less emissions.

The transport, storage, and packaging of food also contributes up to 4% of emissions.[4] However, compared to rural field farming, vertical farms are located in cities meaning transport emissions are nearly zero. Packaging energy can also be decreased or eliminated, since packaging won’t have to withstand the rigors of traveling 1,500 miles like the average piece of fresh produce in the United States.[11]

Herbicide and pesticide manufacture accounts for up to 1.5% of global emissions.[4] The neat thing about a lot of vertical farms is that they dramatically decrease or eliminate the use of these substances, often opting for nature-inspired solutions such as beneficial insects. As a bonus, most vertical farms are controlled environments, keeping out bad pests and keeping beneficial insects in.

Overall, applying vertical farming on a grand scale offers potential savings across the board for some of the biggest emitters in the business of food. There is potential to reduce over 20% of global greenhouse gas emissions through vertical farming’s impacts on:

Land Cover Change

Food Waste

Nitrous Oxide (N 2 O) Emissions

Biomass Burning

Fertilizer Use

Refrigeration

Transport

Storage

Packaging

Herbicide and Pesticide Use

Vertical farming is an easy way to help the environment with the added economic incentive of increased production in less space. Why wouldn’t we want to embrace it?

Source Min (%) Max (%) Land Cover Change 4.54% 12.70% Food Loss & Waste* 6.33% 9.67% N 2 O from Fertilizers 4.02% 4.50% Methane from Ruminants 3.38% 3.79% Biomass Burning 1.27% 1.42% Rice Production 1.16% 1.30% Fertilizer Manufacture 0.58% 1.11% Refrigeration 0.95% 1.01% Manure Management 0.74% 0.83% Transport, Storage, Packaging 0.77% 0.82% Retail 0.43% 0.46% Processing 0.37% 0.40% Catering 0.31% 0.33% Landfill Emissions 0.14% 0.15% Animal Feed 0.12% 0.12% Herbicide & Pesticide 0.01% 0.12% FIG. 1. Global GHG Emissions by Source. These numbers have been calculated from information contained in [4] and were ranked by maximum emissions. *Food Loss & Waste was roughly calculated using [4] and [13], and accounts for the indirect effects of landfilled or lost food.

Sources

[1] World Population Prospects, 2012 Revision. United Nations Population Division. 2012.

[2] World Urbanization Prospects, 2014 Revision. United Nations Population Division. 2014.

[3] How to Feed the World in 2050. FAO. 2009.

[4] Climate Change and Food Systems. Vermeulen et al. 2012.

[13] Global Food Losses and Food Waste. FAO. 2011.

[5] http://www3.epa.gov/climatechange/ghgemissions/sources.html

[6] Temperature Impacts on Economic Growth Warrant Stringent Mitigation Policy. Moore et. al. 2014.

[7] Effects of Elevated CO2 on the Protein Concentration of Food Crops: A Meta-Analysis. Taub et. al. 2008.

[8] Emerging Food-Borne Zoonoses. Schlundt et. al. 2004.

[9] Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990-2013. US EPA. 2013.

[10] Reviving Dead Zones. Laurence Mee. 2006.

[11] Energy Use in the U.S. Food System: A Summary of Existing Research and Analysis. John Hendrickson. 1996.

[12] Food Refrigeration: What is the Contribution to Greenhouse Gas Emissions and How Might Emissions Be Reduced? T. Garnett. 2007.

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