The timeframe for evaluating climate change projections depends on the longevity of ​the decision you are making. For example, the lifespan of built infrastructure may be subject to climate-related impacts decades into the future. ​Such decisions often involve substantial investment, which itself elevates the risk imposed by climate change.

Alternatively, a given policy may be in effect for​ a shorter period of time. When addressing urban flooding impacts on roads or infrastructure within the context of a local comprehensive plan, decision makers are likely concerned with a 10-year horizon.