1 The 2008 Climate Change Act allows UK government to mandate or invite certain organisations to produce reports to assess the impacts of 
climate change on their operations and present proposals for adaptation. https://www.gov.uk/government/collections/climate-change-
adaptationreporting-second-round-reports
2  Expected in 2018, the National Adaptation Programme will be supported by the Evidence Report of the Adaptation Sub-Committee of the 
Committee on Climate Change (ASC): https://www.theccc.org.uk/uk-climate-change-risk-assessment-2017/introduction-to-the-ccra/ 
3  Under the 2008 Climate Change Act, organisations are invited to produce Adaptation Reporting Power reports to assess the impacts of climate 
change on their operations and present proposals for adaptation: https://www.gov.uk/government/collections/climate-change-adaptation-
reporting-second-round-reports 
4  Spatial coherence means that climate projections can be compared between locations and aggregated over larger areas, enabling climate 
change to be assessed consistently over larger study areas.
5 http://www.metoffice.gov.uk/research/modelling-systems/unified-model/climate-models/hadgem3
6  Coupled model intercomparison project phase 5, see http://cmip-pcmdi.llnl.gov/cmip5/ 
7  Kendon, E. J., Roberts, N. M., Senior, C. A. & Roberts, M. J.  Realism of rainfall in a very high resolution regional climate model. J. Clim. 25, 
5791–5806 (2012) http://journals.ametsoc.org/doi/abs/10.1175/JCLI-D-11-00562.1
UK CLIMATE PROJECTIONS: A PROJECT OVERVIEW 
What is UKCP18 
and why do we need it?
Following the historic Paris Agreement on Climate 
Change in December 2015, the Department of 
Environment, Food and Rural Affairs announced a 
major upgrade to the UK Climate Projections.
The UKCP18 project will build upon the current set 
of projections (UKCP09) to provide the most up-to-
date assessment of how the climate of the UK may 
change over the 21st century.  This information 
will be essential to future Climate Change Risk 
Assessments1 and to equip the UK with information 
to help adapt to the challenges and opportunities of 
climate change in line with the National Adaptation 
Programme2.
Organisations and individual users will use UKCP18 
to inform risk assessments and adaptation plans 
to ensure they are resilient to extreme weather 
and climate change. Some organisations will use 
UKCP18 in responding to the Adaptation Reporting 
Power3 for example.
What improvements 
does UKCP18 deliver?
UKCP18 will benefit from a range of developments 
since the release of UKCP09, including: 
• Greater understanding of user needs as a result 
of the adaptation community’s use of UKCP09 
projections and the subsequent feedback – user 
workshops indicated that users supported the 
continued use of probabilistic projections and the 
importance of spatially coherent information4. 
• Advances in climate models in recent years, such 
as the Met Office Hadley Centre HadGEM35 model 
and the CMIP56 set of models.  Improvements 
include better representation of the past 
climate, the inclusion of more cloud and aerosol 
processes and the ability to model important 
climate phenomena such as the El-Niño Southern 
Oscillation (ENSO). 
• Groundbreaking Met Office research on 
modelling of extreme events in high resolution 
regional climate models7. 
• The increased quantity and range of observations 
available since 2009. 
• Use of the new Met Office supercomputer, 
enabling a credible range of climate projections to 
be generated in greater spatial detail.