(B)iodiversity can act as a natural "insurance policy" against sudden environmental changes and a buffer against losses caused by them (as well as by pests and diseases). Biodiversity is essential for reliable and stable long-term food production. The famines in Ireland in the 19th century and in Ethiopia in the late 20th century provide clear evidence of the vulnerability of undiversified crops to environmental changes, and the dramatic consequences of such vulnerability for the population.
Crop diversity can also deliver important ecosystem benefits. Varieties that are tolerant to drought and flood can not only increase productivity, but also can prevent soil erosion and desertification. In southern Ghana, for example, farmers have managed to reduce crop failures arising from rainfall variability and unpredictability by cultivating several drought-tolerant types of the same crop species. In addition, crop diversification has reduced the need for costly and environmentally damaging pesticides.
So I am convinced that we should raise the profile of biodiversity in tackling climate change and food insecurity, and that we need more high-level attention to this subject.