Climate models: What they show us and how they can be used in planning

This guide provides background information on the use of global climate models (GCM) for resilience planning in Africa, primarily over medium to long time frames (e.g. 5–40 years). When designing an irrigation scheme, for example, it is useful to know what rainfall might be in 40 years’ time to inform design, manage operations, and ensure the intended benefits will be sustainable. Infrastructural interventions have a long lifespan and therefore require consideration of both current and future conditions. The location of the dam may need to change, and its design could be less costly if it will need to hold less water.

Medium-term planning can take into account the effect of likely future conditions based on projections, in conjunction with current knowledge of weather conditions and how they vary from place to place. This enables identification of robust strategies for what crops to promote and what farming techniques to investigate. The specifics of decisions – in terms of exactly what to plant and when in different places – can be part of shortterm planning (e.g. annual), and can be informed by weather information such as seasonal forecasts. However, knowing the likely longer-term situation can enable adaptive planning to meet national strategic goals, such as long-term food security and livelihood resilience.