Guidelines for using the VCP19 projections

Key Messages

1. Assessing the impact of future climate is complex – plan to allow adequate time for consultation and data collation (see Technical Report section 7.2).
2. You are likely to need advice and guidance from experts in the field (see Technical Report section 7.5).
3. Think carefully about the communication needs of your stakeholders – this can influence your choice of climate information (see Technical Report section 7.1).
4. In most cases, using just the mean or median climate projections will not be appropriate (see Technical Report section 7.2).
5. In most cases, use a method such as the Climate Futures approach to identify an appropriate subset of models to use in your assessment (see Technical Report section 7.3).
6. The VCP19 high-resolution data are high quality and add important value to the lower-resolution GCM data in some regions; nevertheless, if GCM results project a high-impact future that is not projected by the VCP19 data, the GCM results should be used unless there is a compelling reason not to.
7. Ensure the ranges of projected change are adequately accounted for in your assessment (see Technical Report section 7.3).
8. There are multiple sources of uncertainty and there always will be. To deal with this, be sure to evaluate multiple emissions scenarios and explore the full ranges of plausible change from all available data sources (see Technical Report section 7.3).
9. There is no such thing as a ‘most accurate’ climate model or ‘most likely’ emissions scenario. All of the models included in the Climate Futures Toolkit produce climates that are physically plausible for a given emissions scenario. Instead, aim to use a representative subset of the available data (see Technical Report section 7.3).
10. The climate has always been naturally variable; this variability now occurs on top of climate trends; over short time scales, climate variability will be the largest influence on the climate we experience (see Technical Report section 5.2.2).
11. Be aware that future climate data have a range of limitations and take this into account (see Technical Report section 4).
12. Fine resolution data are not always needed and do not necessarily provide better information (see Technical Report sections 4.2 and 7.3).