Now that the dust has settled since the publication of the UK’s Climate Change Risk Assessment (CCRA), we are starting to reflect on the true value of this work and where we should go from here, bearing in mind that this assessment was just the first in an open-ended cycle of assessments to be completed every five years.
In July 2012, the UK Adaptation Sub-Committee (ASC) commissioned an independent review of the CCRA, which described the project as ‘a heroic effort given the time available’ (Wilby, 2012 ).
Some facts about the CCRA
- Around 700 separate impacts were identified, with over 100 analysed in detail
- Over 4000 days of work were completed by the HR Wallingford led consortium
- 33 final publications were produced (nearly 4000 pages, over 1.5 million words)
- 31 workshops were held during the 2.5 year project
- Over 1800 stakeholders were involved
There is a widely held view that the process of producing this first CCRA was as valuable as the findings. Never before has a single project attempted to bring together such diverse sectors as biodiversity and business in a way that would enable risks to be compared using the same language and criteria. It was essential that we tackled this head on if there was to be a sensible discussion regarding the relative importance of different risks for the UK. The challenge was enormous, and developing an agreed methodology that could be applied across all sectors took a long time at the start of the project. Having to do things differently, however, can be insightful and encourage advances in understanding.
The use of response functions was a particularly important element of the approach, born out of the necessity to find a workable method that could assimilate different types of evidence ranging from detailed modelling studies to expert elicitation methods. Development of response functions helped us to understand the sensitivity of impacts or consequences to changing climate conditions. Their use, importantly, also allowed us to disaggregate climate and non-climate drivers of risk. They need to be used with caution, however; they can lead to over-simplification of some responses (such as crop yields) and extrapolation beyond the available evidence can only be done with considerable care. Having said that, there remains merit in applying a similar approach in future. The approach may evolve in a couple of directions. Firstly, for sectors with detailed modelling, this should be used more fully in future, but presenting sensitivities to climate in the form of a single or multiple response functions would remain useful for comparing different risks. Secondly, where the evidence remains weak, there should be greater use of expert elicitation and less emphasis on quantification, but again results should be presented in a comparable way.
Examples of headline findings from the CCRA
"Annual damage to properties could rise from the current figure of £1.2 billion for England and Wales alone to £2-12 billion* by the 2080s"
- Water scarcity
"By the 2050s, between 27 million and 59 million people in the UK may be living in areas affected by water supply-demand deficits."
- Health risks
"Premature deaths due to cold winters are projected to decrease significantly in the UK (e.g. by between 3900 and 24,000 by the 2050s) whilst premature deaths due to hotter summers are projected to increase (e.g. by between 580 and 5900 by the 2050s)."
- Ecosystem risks
"Some species could benefit, but many more would be negatively impacted in the UK, having knock-on effects on habitats and on the goods and services that ecosystems provide."
Due to the trade-off that had to be made between complexity of analysis and compatibility between risks; issues with data availability; and working in some areas of science that are still not well established (such as ecosystem services) there are clearly limitations to what we were able to achieve first time round. But this has led to a much better understanding of the major knowledge and data gaps and, as concluded by the ASC review, “These outputs provide a firm basis for a more focused and deeper risk assessment next time” and for subsequent cycles.
The legacy of the CCRA also goes beyond the UK. There is considerable international interest in the CCRA approach, particularly in North America and Asia, where members of the HR Wallingford project team have already carried out a number of presentations. As part of the United Nations Framework Convention on Climate Change (UNFCCC), a large number of countries are required to complete assessments of the risk of loss and damage associated with the adverse effects of climate change. The challenge for many countries will be the variability in the quantity and quality of data available for undertaking these assessments, but there is wide recognition that efforts need to be made sooner rather than later in building resilience to the current and future climate. Therefore, having an approach that has built in flexibility with regards to which risks are analysed in detail and to what level of complexity (depending on available data and models), is a very important requirement of any risk assessment, whether at the national, local, sector or organisational scale.
The CCRA method and recommendations report can be found at http://ccra.hrwallingford.com/.