Online climate change projections report 1 Introduction
This report provides background information on, and key findings from, the new projections of UK climate change in the 21st century, known as UKCP09. It is designed for anyone who wants to know about the projections themselves, ranging from general awareness to their application in impacts and adaptation assessments. In particular, the projections have been designed as input to the difficult choices that decision makers will need to make, in sectors such as transport, healthcare, water resources and coastal defences, to ensure the UK is adapting well to the changes in climate that have already begun and are likely to grow in future.
This report has a rather different purpose to its predecessor in UKCIP02; it is not designed to give a comprehensive description, in graphics or text, of the changes that are projected. Many of these can be seen on the UKCP09 website, and custom products can be generated from the User Interface. Because the UKCP09 projections are more informative, but also more complex, than previous UKCIP scenarios, the report discusses at some length why and how they have been developed, and how they are presented, so that users can get the most out of them.
This report has been reviewed, firstly by the project Steering Group and User Panel, and secondly by a smaller international panel of experts, who also reviewed the methodology used to generate the probabilistic projections. Reviewers’ comments have been taken into account in improving the reports.
Chapter 1 discusses briefly why the UKCP09 projections are needed, what information they provide, the uncertainties that they have been designed to treat and how this is done. Chapter 2 discusses causes of uncertainty in climate change projections, and gives a simplified description of the method used to derive the UKCP09 projections, with Chapter 3 going into much more detail on the methodology. Chapter 4 summarises the key findings based on the monthly and seasonal projections for regions of the UK, and displays maps and graphs of changes for some temperature and precipitation variables. Chapter 5 deals with daily time series of recent and future climate from the Met Office Hadley Centre (Met Office) regional climate model. Finally, there are a number of annexes which allow the user to go into greater depth; in particular Annex 2 identifies some of the uncertainties in the UKCP09 projections themselves.
The components of UKCP09 are shown diagrammatically in Figure 1.1; they are supported by a number of publications, some in hard copy and all on line.