Step 4: Find Relevant Climate Model Data
Climate model data associated with your selected RCPs may be obtained from GCMs, downscaled models or bias-corrected model data. Choosing the right data for your purpose is an important part of undertaking risk assessments.
You should consider both the type of data required and what is available from accessible sources at the desired time and space scales. Explore and access as large a range of model data as possible.
Climate model data sources
There are a number of sources of climate model data.
The first and main source of climate model information should be the GCM simulation data that are associated with the most recent IPCC assessment reports. These model simulations are up-to-date. The model experiments are globally co-ordinated so that there can be some consistency when comparing different models for a given emission scenario. These typically lower spatial resolution GCM simulation data can be used to assess the full range of possible futures. It is recommended to use all GCMs simulation data if possible. If it is not possible, do step 6 to select the sub-set of the GCMs.
Fine-resolution climate data from downscaled model simulation may not be available or may only be available for a limited sub-set of RCPs and GCMs. If this is the case and if you need fine-resolution climate data, there are a range of methods to generate higher resolution climate projections (also see step 9).
Much current GCM climate information is from the fifth phase of the Coupled Model Intercomparison Project (CMIP5), which is part of the World Climate Research Programme. However, this website is designed to provide basic gridded global data, so it may be challenging to extract only the data required for your application.
A good way of finding what climate projection information is available in the Asia-Pacific region is to use the RCCAP portal’s data search facility.
Ensure that you understand the type of model data you obtained, how the data was generated and that the data is meeting your need. Some sources provide raw climate model data simulated by GCMs or RCMs. Others may give bias-corrected model data that could be applied directly to an impact model, so you do not need to conduct further bias correction (step 9). You need to check to make sure that whatever data you have will serve your purpose. If, for example, the sources provide climate projections data, some of the things you should consider include:
- the time periods (both the baseline and future period)
- whether the projected changes are provided in absolute (e.g. °C) or in relative (e.g. %) units
- whether the projected changes are given for a specific location, box, region, or country
- whether the projected changes are provided for each model or for the median of the all-models ensemble.
Conduct an initial check of the reliability of the climate model data for your region. This could be conducted through literature review and/or consulting experts. This could be useful before deciding to conduct the climate model data evaluation (step 5). For instance, if your resource is constrained and you have found enough evidence about the reliability of the model data you are interested with, then you may not need to evaluate your climate model data in great detail. You could use and cite results from previous works instead.