UKCP18: A Flood of
New Climate Change Information

In November 2018, the UK Government launched UKCP18, the latest update to the UK Climate Projections. In this blog, we take a look at what UKCP18 offers and how our industry may find it useful in the context of flood risk.

What are UK Climate Projections?

The UK Climate Projections have been developed and updated over the past 25 years to inform government policy, educate the public and provide guidance to businesses on how to manage the implications of climate change. Nine years after the last release of UKCP09, the data has now been updated to take advantage of the latest climate research and technological advances in climate modelling. Increased computing power enables a larger set of climate models to be run at an increased spatial resolution, more effectively representing the effects of local land use and providing additional information on the uncertainty of the projections. An additional decade of observed climate data is also available.

The UK Climate Projections are important as a source of information for the UK Climate Change Risk Assessment (CCRA), which the UK Government is required by law to publish every five years. The CCRA informs how the UK will manage the risks and opportunities arising from climate change in areas such as flood risk, water availability, infrastructure planning, economic development, public health, agriculture and the natural environment.

The UKCP18 projections

UKCP18 consists of three components: land projections (global, regional and probabilistic) , marine projections and past climate measurements. These datasets can be used to examine how the UK climate has changed during the 20th century and how it is expected to change during the 21st century. Data are available for a range of climate variables that include temperature, rainfall, sea level pressure, humidity, wind speed and sea level rise.

Pictured right: The different components of UKCP18. Source: Lowe et al. (2018)

The global and regional projections are available for a low emissions scenario that is broadly comparable with a 2°C warming scenario (in line with the threshold set by the Paris Agreement in 2015), whereas the probabilistic projections are provided for a range of scenarios that represent possible socio-economic development in the future. If you want to know more about how climate scientists project the future to create these climate projections, our recent blog on Demystifying Climate Scenarios is a good place to start.

What can UKCP18 be used for?

There are many different applications for UKCP18. Perhaps most notably for insurance and mortgage lending portfolios, UKCP18 offers a more detailed insight into the potential changes to UK climate we may experience in the coming years. For example, the projections suggest that, broadly speaking, winters are likely to be warmer and wetter, while summers are likely to be hotter and drier but with the possibility of more intense localised rainfall events.

Left: the change in winter season (Dec-Feb) rainfall projected for the period 2040-2059 relative to the baseline climatology 1981-2000 for the low emissions scenario. Right: the change in summer season (Jun-Aug) rainfall.

Behind these headlines, there are likely to be localised impacts from climate change and UKCP18 may help you to explore the different risks and opportunities for your business. For example, where is the greatest projected change in rainfall located and how might this affect your portfolio? What is the likelihood that a critical climate threshold may be exceeded? Are there actions that your business could take now to reduce impact in the future?

Additional functionality means that the new climate data can be analysed in new ways. For example, outputs can be generated for specific years rather than the 30-year averages that were available in UKCP09. This could enable analysis of climate change in the coming decade, to inform sustainability and corporate social responsibility decisions. The data can also be analysed for a specific location, region or major river basin in the UK to identify changes in risk to specific parts of a portfolio.

Translating UKCP18 data to inform users how flood risk may change across the UK is where JBA can help. Whether this be from flood risk assessments or more bespoke consultancy, we are continuing to explore ways to convey climate change research in a relevant and meaningful way to our clients. A key example of this is our UK Climate Change Flood Model, which applies climate data to flood hazard to provide an indication of potential losses by 2040.

For more information on our climate change work, please get in touch.

Acknowledgements

Data and information used in this blog were used under the terms of the Open Government Licence.

References

Lowe, J.A., Bernie, D., Bett, P.E., Bricheno, L., Brown, S. et al, 2018. UKCP18 Science Overview. [online] Available at: https://www.metoffice.gov.uk/pub/data/weather/uk/ukcp18/science-reports/UKCP18-Overview-report.pdf [Accessed 1 March 2019].