## 5 Climate Change  
Historic geostructures will experience future changes in climate, including changes in seasonal patterns of precipitation and drought owing to increases in surface temperature. These predicted future surface temperature changes are based on several scenarios designated as Representative Concentration Pathways (RCP) [51]. RCPs are split by a range of radiative forcing values found in the literature resulting from prediction of internal drivers such as greenhouse gases against a preindustrial baseline, at the year 2100 [52]. Radiative forcing concerns the net change in radiative flux in the upper atmosphere, expressed as Watts per square meter [53]. The surface temperature change and assumptions for each of the radiative forcing pathways is presented in Table 3. It clearly demonstrates the indeterminate but probabilistic nature of future temperature change and thus the need to factor these probabilities into infrastructure management and design. The understanding of the impact of climate change in the UK began with development of the Climate Change Impacts Review Group (CCIRG), which produced CCIRG91 followed by CCIRG96, in both 1991 and 1996, respectively. Subsequently, in 1998, the UK Climate Impacts Programme (UKCIP) was developed and published the UKCIP98 report. Unlike the original work, UKCIP98 produced climate scenarios which were aimed at assisting with national assessments of the impacts and adaptation to climate change [54]. Thereafter, UKCIP02 scenarios produced higher spatial resolutions based off four IPCC storylines [54]. More recently, UK Climate Projections (UKCP) have been published beginning with UKCP09 scenarios in 2009. This approach allowed for future climate to be quantified in probabilistic projections used for understanding uncertainty required for adaptation [55]. UKCP18 represents the most recent generation of these climate models, \begin{table}
\begin{tabular}{c c c} \hline \hline
**RCP (Wm\({}^{2}\))** & **Temp Change by 2081–2100 (\({}^{\circ}\)C)** & **Assumptions** \\ \hline \multirow{4}{*}{2.6} & \multirow{4}{*}{1.6} & Population—approx. 8.75 billion by 2100 \\  & & Global GDP increase of \$375 trillion by 2100 \\  & & Primary energy consumption of 750 EJ by 2100 \\  & & Use of bioenergy and carbon capture and storage resulting in negative emissions by 2100 \\ \hline \multirow{4}{*}{4.5} & \multirow{4}{*}{2.8} & Population—approx. 9 billion by 2100 \\  & & Global GDP increase of \$300 trillion by 2100 \\  & & Primary energy consumption of 900 EJ by 2100 \\  & & Same energy mix as RCP 2.6 but a less extreme move to low-carbon technologies and larger energy demand \\ \hline \multirow{4}{*}{6.0} & \multirow{4}{*}{2.4} & Population—approx. 9.75 billion by 2100 \\  & & Global GDP increase of \$225 trillion by 2100 \\  & & Primary energy consumption of 750 EJ by 2100 \\  & & Same use of fossil fuels as RCP 8.5 but reduction in energy demand reduces release of emissions \\ \hline \multirow{4}{*}{8.5} & \multirow{4}{*}{4.3} & Population—12 billion by 2100 \\  & & Low per capita income growth \\ \cline{1-1}  & & Global GDP increase of \$250 trillion by 2100 \\ \cline{1-1}  & & High primary energy consumption 1750 EJ by 2100 \\ \cline{1-1}  & & Increase in use of fossil fuels due to low technology development \\ \hline \hline \end{tabular}
\end{table} 
Table 3: RCPs and their resulting global mean surface temperature change from pre-industrial baseline by 2100 (adapted from Met Office [51] and [PERSON], et al. [52]). although as UKCP09 predates UKCP18, UKCP09 is found within much of the literature prior to 2018. UKCP18 builds on past predictions and provides a more precise spatial resolution [8]. The analysis predominantly agreed with the previous studies, showing (for a high emissions scenario RCP 8.5) that by the year 2070, the UK climate will experience more climatic extremes. It predicts increased seasonal temperatures for both winter (warming range of 0.7 \({}^{\circ}\)C-4.2 \({}^{\circ}\)C) and summer (warming range of 0.9 \({}^{\circ}\)C-5.4 \({}^{\circ}\)C).