The Importance of Crop Diversity for Climate Change Adaptation

Our global food system depends on a remarkably narrow base of crop diversity. Just three crops - rice, maize and wheat - provide nearly 60% of the plant-based calories humans consume. This heavy reliance on a few staple crops makes our food supply vulnerable to pests, disease and climate change impacts like drought and flooding. To strengthen the resilience of agriculture, we urgently need to conserve and make better use of crop genetic diversity.

Crop Diversity Enables Adaptation

The genetic diversity of crops allows for adaptation in the face of environmental changes. Different varieties of the same crop can vary enormously in their yield potential, nutritional content, and resistance to stresses like heat, drought or salinity. For example, research shows that some varieties of rice can withstand higher temperatures and require less water than others. With climate change bringing higher temperatures, more erratic rainfall, and saline intrusion in coastal areas, these traits will become increasingly valuable. Access to diverse seed varieties gives farmers options to switch to more suitable crops and varieties as conditions change.

Genetic Erosion Threatens Resilience

However, in many parts of the world, crop diversity is being lost as commercial agriculture promotes genetically uniform, high-yielding varieties at the expense of traditional farmer varieties. This trend toward crop genetic erosion and dependence on a very narrow pool of commercial crop varieties poses huge risks. A disease or pest outbreak that affects those few crop varieties could devastate large swaths of our food system. This genetic vulnerability in our staple crops means that climate stresses could trigger massive crop failures and food insecurity.

Community-Based Conservation is Key

Farmers and local communities have a key role to play in conserving crop diversity and making it available for adaptation. Smallholder farmers have long cultivated diverse traditional crop varieties, developing locally adapted varieties and saving their own seed. Supporting on-farm conservation of crop diversity maintains genetic resources and enables continual adaptation. Community seed banks provide another opportunity - they function as repositories where farmers can store and access diverse, locally adapted seeds. Such grassroots, community-based efforts to manage and share crop genetic resources are an important facet of food system resilience.

Enabling Policies Needed

To harness the adaptability within crop diversity, research and policies should further support community-based conservation efforts. Plant breeders must integrate diverse traditional farmer varieties in developing new climate-resilient crops. Policymakers should protect farmer seed systems from stringent intellectual property laws and seed regulations that restrict farmers from freely saving, exchanging and selling seed. Ultimately, the rich genetic diversity of crops represents the biological capacity for adaptation - but communities of farmers must be enabled to co-manage this genetic wealth.

Conserve Crop Diversity for Resilience

The genetic uniformity of modern commercial agriculture is a precarious gamble given the uncertainties of climate change. Crop diversity offers resilience, but is eroding rapidly. Conserving diverse traditional varieties and making these resources locally available will be key for helping farms and communities adapt to new conditions and withstand unexpected shocks. The time is ripe to foster greater crop diversity - and recognize farming communities as vital allies in this effort.