Welcome to this web guide on using climate forecasts in the planning process.

Scenario building with climate forecasts
Climate forecasts are a potentially valuable tool for many planning situations. But the probabilistic nature of climate forecasts means that we need to use special planning strategies. One such strategy is scenario building. Scenario building constructs scenarios of what the future might be like by combining information on (1) the current situation, (2) the range of possible climate outcomes, and (3) the variety of decisions we can make. The scenarios help us appreciate the consequences of any potential decisions, and therefore they can help us to choose the most appropriate ones.

About this guide
The scenario-building process applies to a broad range of planning situations, but the actual scenarios that are built are unique to each situation. This guide takes you step-by-step through the process of scenario building with climate forecasts for your situation. Each step includes a short description of the issues you need to consider, the information you need to gather, and where you can go for more information.

Using this guide
You can go through the steps in the guide in two ways. Under 'Principles', you will find a general description of each step. This is a good place to start. To see examples of the steps for specific situations, go to 'Cases'. This will open a new frame in your window with a menu of illustrative case studies. Once you select a case study, you can see and navigate through the steps in both the case study and the general principles at the same time.

To build the scenarios, you might also want to look up some climate information for your area on the IRI web site. Under 'Tutorials' you will find four tutorials on finding specific information on the web site and customizing it to your requirements. For your convenience, we have put the tutorials and the IRI web site side by side, so that you can try the instructions as you go through the tutorial.