Written by: Lesley Pinto and Jonathan Segeren
Project Drawdown is a resource providing climate solutions that both aid in reducing the level of greenhouse gases in the atmosphere and improving human wellbeing and quality of life. In this article, we summarize six potential solutions recommended by Project Drawdown that can be adapted in an urban agriculture setting.
Composting – 1.13 to 1.4 gigatons of CO2 reduced.
Composting is the process of converting organic waste into soil carbon. It can be used as a means of lessening food waste and repurposing the organic waste produced. In the process of decomposition, organic wastes release large quantities of greenhouse gases, and the incorporation of waste management systems of this nature can reduce emissions by 50% . Composting is commonplace in urban farm environments and provides a cost-friendly option for improving soil health and can be practiced at almost any scale. The product of compost enhances the structure and fertility of soil, and can reduce the need for nitrogen fertilizers1.
Sustainable Intensification – 1.36 to 0.68 gigatons of CO2 reduced.
Project Drawdown believes in intensifying smallholder farm production, which helps small-scale farms to sustainably increase their yield with crop diversification and agro ecological pest management. This form of pest management uses ecologically mindful agriculture practices. This can sequester and prevent the loss of 0.68 GT of CO2 emissions worldwide by 20501 with no input costs to implement this form of land management. Since the typical urban farm is small and intensive, many management practices that go along with increasing agriculture intensity can be readily implemented. Globally, about 456 million hectares of land area are used for urban and peri-urban agriculture1. If one-third of these farms increase their intensification practices, they will be capable of sequestering a maximum of 6 GT of CO2 by 2050, based on Project Drawdown’s projected values of sequestration and mitigation from these farming practices. Growing more food on less land prevents carbon loss from growing soil and allows areas that are no longer required for production to be regenerated.
Accessible Transportation - 2.83 to 3.51 gigatons of CO2 reduced.
The walkability of an area directly correlates with its level of accessibility. The use of alternative transportation systems such as streetcars, buses, and subways can drastically decrease the amount of carbon emissions. Pedestrian-friendly cities encourage walking as a form of transportation, one of the only forms of transportation that produce zero emissions. This is a highly affordable alternative. Both of these solutions are suggested with the aim of reducing the use of internal combustion engine cars. With the expected growth of urban areas, comes an increase in population and responsibility of our resource use. More walkable cities and improved public transit systems go hand-in-hand with accessing nutritious food. A community-based approach to this issue could include foodshare programs with community gardens or local urban farms.
Reducing Value-Chain Food Waste - 88.5 to 102.2 gigatons of CO2 reduced.
Centralizing agriculture around areas of population and reducing food kilometers has been shown to reduce the quantity of food lost in transportation and storage of food. Delays, inadequate storage conditions, mishandling and accidental introduction of pests are all factors that create food waste in a lengthened food value chain that can be mitigated by urban agriculture. While the issue of food waste is well known and documented, the losses associated with transportation and storage are not quantified quite well, however it is known that fruits and vegetables are lost more readily than grains, with global ranges of losses for transportation and storage between 4-50% for fruits and vegetables and between 1-30% for grains1. Shortening physical and social value chains and offering products directly to consumers are all ways that the food waste associated with transportation, storage and retail.
Irrigation Efficiency - 1.13 to 2.07 gigatons CO2 reduced.
Urban agriculture is unique from other types of agriculture in terms of its water requirements and water availability. Urban agriculture can increase water use efficiency using drip irrigation, swales, mulches and water harvesting for in-soil production, and recirculating systems and leachate recapture for potted and hydroponic systems. While no specific numbers were proposed due to the variation of irrigation requirements, possible techniques and deployments of techniques at scales, a reasonable figure proposed is around a 40 percent reduction by adopting these tactics. This water savings can be used elsewhere in the urban environment as accessible potable water.
Regenerative Annual Cropping - 15.12 to 23.21 gigatons CO2 reduced.
Much of urban agriculture revolves around annual horticulture crops. A regenerative approach to this could be the inclusion of mulches and compost, exclusion of pesticides, or striving towards a regenerative organic certificate. This practice poses a unique opportunity in the urban environment, where there are many sources of organic matter that can be composted and applied to crops, creating a circular economy within the community. While this method is not the greatest at sequestering carbon, in urban centers, it can be used to ensure nutrients in organic waste recirculate back into the agricultural systems, and rising popularity of organic and conservation agriculture will ensure that there is adoption of this form of sequestration.
To learn more about Project Drawdown and climate solutions for other industries, visit Project Drawdown’s website. You can also check out additional Understory articles featuring organic agriculture and advances in carbon sequestration in agriculture.
Project Drawdown, 2022. https://drawdown.org/solutions
 Tendero, M., & Guyot Phung, C. (2019). The revival of urban agriculture: An opportunity for the composting stream. Field Actions Science Reports. The Journal of Field Actions, Special Issue 20, Article Special Issue 20.
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