Urbanization and Land Use Change, Impacts on City Region Food Security

A special report from the IPCC from 2019 produced evidence that land and the way that land is used is critically important as both a sink and a source of greenhouse gas emissions and even though land sequesters almost a third of all anthropogenic greenhouse gas emissions, the means which societies produce food and manages land needs to be addressed in order to limit temperature rise and stay within the boundaries set out by the Paris Agreement.

Land use involves the management and modification of natural environment or wilderness into built environments such as settlements and semi natural habitats such as arable fields, pastures, and managed woods. It is estimated that around 23% of anthropogenic greenhouse gas emissions come from agriculture, forestry, and other land uses (AFOLU). This is caused somewhat by land use change in clearing forests to make way for more agricultural lands. Increased agricultural land is expected to increase methane emissions as 44% of recent anthropogenic methane comes from agriculture, peatland draining and other land based sources.

Land is also a greenhouse gas sink. The world’s lands are removing more emissions than they emit. Between 2007 and 2016, 6 Gt of CO2 was removed a year by land, but this effectiveness of land as a greenhouse sink is threatened by deforestation and soil degradation. Curbing deforestation will have the largest potential for reducing emission, however substantial changes to how agriculture is carried out and food is produced are needed including shifting towards a more sustainable diet and reducing food loss and waste. The land sector can also sequester carbon from the atmosphere. The IPCC report points to trees and forests as having the greatest potential with afforestation and reforestation areas for development. Bioenergy, Carbon Capture and Storage (BACCS) is a system which utilises biomass for energy and captures the carbon and stores it before release into the atmosphere is another area deserving of attention however the report suggests more research is needed concerning limitations such as land use competition and additional sustainability issues. Interventions must be considered carefully however. For instance planting forests on native grassland could reduce the soils potential as a sink. Also planting dark evergreen forests would lead to a darker surface and reduce solar reflection and greater absorption of solar radiation. 

The Food and Land Use Coalition report 2019 outlined the hidden costs of land use systems in addition to the environmental costs including costs to public health with poor diet contributing to poor health, one in five children under the age of five is stunted caused by undernutrition and more than 820 million people mostly in Sub Saharan Africa and South Asia, still regularly go hungry. Going at the current rate half the world’s population will experience malnutrition by 2030 placing additional pressure on limited resources. The economic structure of the food and land use systems excludes hundreds of millions of people from making a fair livelihood from their labor. A lack of access to markets and low levels of assets are major contributors to the imbalance and this continues along the value chain. 740 million people are living on less than $1.90 a day ppp and of this proportion two thirds are agricultural workers and dependants. These agricultural workers are stewards of vitally important land and insufficient and unfair land tenure rights renders people incapable of making changes to agricultural and land use practices necessary to curb or limit emissions. 370 million indeginous people and local communities are stewards of forty percent of the planet’s ecologically intact landscapes (ipccresponse.org/home indeginous response), only ten percent of these people are formally recognised by governments as having tenure rights. 

These hidden costs are estimated to amount to  $12 trillion a year and are expected to grow to $16 trillion a year by 2050 and food and land systems are expected to compound their effect on greenhouse gas emissions if they continue as they do currently (world Bank poverty and prosperity 2018). Events previously considered tail end events will become more probable and areas which will be most vulnerable to these effects are areas like Sub saharan Africa or South East Asia where recent progress and livelihood improvements will be threatened. 

The Food and Land Use report highlighted a reform agenda based around ten critical transitions. 

1. Healthy diets 
2. Productive and regenerative agriculture
3. Protecting and restoring nature
4. A healthy and productive ocean
5. Diversifying protein supply
6. Reducing food loss and waste
7. Local loops and linkages
8. Harnessing the digital revolution
9. Stronger rural livelihoods
10. Gender and demography

The Food and Land Use research team evaluated two core scenarios based on these critical transitions, the Current Trends scenario and the Better Futures scenario. The current trends scenario placed the SDGs and the goals of the Paris Agreement out of reach. However these ten critical transitions and the Better Futures Scenario could drive the food and land sector to provide up to one third of the mitigation required for the 1.5c Paris Agreement threshold, halt biodiversity loss, restore ocean fish stocks, and reduce air pollution as a direct result of food and land use systems by up to 80%. This Better Futures scenario relies on ten assumptions of change based on the Critical Transitions

The mitigation potential from AFOLU is substantial. Agriculture and forestry can contribute 32% of what is needed which is more than transport (18%) and industry (12%) combined. This can be achieved if farmers have the tenure rights and the opportunity to improve agriculture management and manage forestry and reforestation responsibly.

Policy tends to treat threats to agriculture, climate and health in isolation yet they are inextricably intertwined. For example until recently the European Union’s Common Agricultural Policy paid  no attention to improved diets in relation to steps to reduced emissions. Strategies to consider land use and food systems as intertwined are necessary. Links between biodiversity, diets and emissions and international learning and knowledge sharing is necessary to ensure a sustainable and equitable outcome. 

The Food, Agriculture, Biodiversity, Land Use and Energy (FABLE) Pathways Consortium was set up in 2018. It proposed three pillars of land management 1. Efficient and resilient agriculture, 2. Conservation and restoration of biodiversity and 3. Food security and healthy diets (FABLE 2018), to consider alongside global supply chains and other demands on land in order to help countries include actions to deliver healthy food, conserve biodiversity and reduce emissions. In addition data must be collected across the three pillars in order to deliver adequate policy including data on land use, soil and water resources, biodiversity, carbon stocks, infrastructure, consumption patterns, food waste and health in order to create useful scenarios , test policy outcomes and develop pathways (Walsman et al Nature and climate 2019).