Economics of Climate Change Adaptation and Risks for England’s Highways Agency – Analysis for Hotter, Drier Summers



Economics of Climate Change Adaptation and Risks for England’s Highways Agency – Analysis for Hotter, Drier Summers

Authors

Helene Vergereau, Atkins, Tamsin Macmillan, Atkins

Description

This study aimed to quantify a sub-set of the risks associated with climate impacts, focusing on hotter, drier summers, and taking account of capital and maintenance costs as well as the cost of delays experienced by trunk road network users

Abstract

Economics of climate change adaptation and risks for England’s Highways Agency – analysis for hotter, drier summers

The UK Government has identified climate change as one of the most serious threats the world faces. In the UK, Climate change is projected to result in changes in temperatures, rainfall patterns and sea levels, as detailed in the UK Climate Projections (UKCP09).
The Highways Agency (the Agency) manages the trunk road network in England and its assets and operations will inevitably be affected, negatively or positively, by these changes in climate and weather.

This study aimed to quantify a sub-set of the risks associated with climate impacts, focusing on hotter, drier summers, and taking account of capital and maintenance costs as well as the cost of delays experienced by trunk road network users.
A key finding of the study was that evidence on the likely impacts of hotter, drier summers on the Agency’s assets is limited and insufficient to support the development of clear potential scenarios. Consequently illustrative ‘What If’ scenarios were developed to provide a basis for quantification. This study therefore provides illustrative estimates of the cost of hotter, drier summers for the Agency if no action is taken (cost of non-action) and of the costs and benefits of adaptation actions.
Hotter, drier summers – what should the Highways Agency prepare for?
Climate modelling was undertaken using the UKCP09 Weather Generator to assess changes in climate variables focusing on hotter, drier summers.
As expected, the most significant increases in summer maximum temperatures are modelled to occur in the East of England, London, the South East and the South West. These increases are however relatively modest. When considered on an annual basis, the number of additional days reaching 32°C or above in the worst affected regions is estimated between 10 and 17 under the Worst Case Scenario and in the 2060s.
Drought analysis also shows modest numbers of additional drought events per 30 year period. The worst affected region is identified as Yorkshire, with the East of England, the East Midlands, the North West and the South East also identified as potentially affected regions.
Estimating the cost of hotter, drier summers for the Highways Agency (cost of climate change)
“What If” scenarios developed for pavements and bridges were used to estimate illustrative costs of hotter and drier summers to the Agency and its users (cost of climate change). Modelling assumptions are based on a reduction in service life for selected pavements and bridges, resulting in additional maintenance costs and associated lane closures and speed restrictions (user delays).
The paper will present these results in more detail but in summary, the cost benefit analysis shows relatively low returns on investment for adaptation measures to reduce the impact of hotter, drier summers on pavements and structures across England, although these results could improve if:
• New evidence becomes available showing that impacts on pavement and structure service life are higher than those assumed in this study or that hotter, drier summers might lead to more marked asset damage requiring more immediate, unplanned maintenance interventions (rather than overnight, planned maintenance as assumed for this study);
• New evidence becomes available showing that baseline routine maintenance involves more frequent and larger scale interventions than those assumed in this study;
• Adaptation costs are lower than assumed in the modelling. For example, for pavements, the industry could respond by providing new heat resistant mixes at no additional costs; and
• Adaptation measures are focussed geographically on areas where maintenance related to climate change damage is likely to lead to the largest user delays.

Key words: Climate change adaptation, roads, economic analysis, user delays, adaptation

Authors: Helene Vergereau, Tamsin Macmillan (Atkins)

Publisher

Association for European Transport