Food system greenhouse gas emission sources are diverse: **Livestock**: methane (CH₄, from ruminant enteric fermentation and manure management) and nitrous oxide (N₂O, from pasture soils and fertilizers) account for approximately 50% of food system total emissions; meat (especially beef) has a far higher carbon footprint than plant-based foods — each kilogram of beef protein’s greenhouse gas equivalent is approximately 10-20 times that of a kilogram of legume protein. **Land use change**: tropical deforestation for agricultural land (primarily in the Amazon and Southeast Asia) is a major carbon emission source. **Fertilizers and pesticides**: nitrogen fertilizer application generates N₂O emissions; nitrogen utilization efficiency is typically only approximately 50% (the remainder lost to water bodies or the atmosphere). **Food loss and waste**: approximately one-third of global food is lost or wasted from production to consumption, accounting for approximately 8-10% of food system total emissions.
## Climate Change Threats to Food Security
**Staple crop yield decline**: IPCC assessments indicate that without adaptation, global corn and wheat yields could fall approximately 7.4% and 5.5% respectively in 2030-2049 compared to the 1981-2010 baseline. Tropical regions (one of the world’s major agricultural producing areas) are most affected; higher-latitude regions may see short-term benefits from climate change (extended growing seasons) but face more extreme weather risks long-term. **Fisheries and oceans**: ocean acidification (pH decline from absorbing excess CO₂) threatens shellfish and coral reef ecosystems; ocean warming alters fishery resource distribution; extreme weather increases fishery infrastructure risks.
## Food System Climate Solutions
**Dietary shift**: reducing animal protein (especially ruminant animals) consumption is the single largest lever for food system decarbonization. EAT-Lancet Commission research shows that reducing meat consumption by approximately 50% while increasing plant-based foods can simultaneously meet global sustainable healthy diet goals and climate goals. **Regenerative Agriculture**: soil carbon sequestration, cover crops, reduced tillage — agricultural practices that improve soil organic matter to sequester carbon can convert part of agriculture from a carbon source to a carbon sink. **Precision Agriculture**: digital technology (sensors, AI, drones) optimizing fertilizer and water use efficiency while maintaining yields and reducing emissions.
See [Climate Change and Human Health](https://sunqi.org/climate-health-impacts-en/) and the [EAT-Lancet Food Planet Health Report](https://eatforum.org/eat-lancet-commission/).
