A systems framework for national assessment of climate risks to infrastructure.

Extreme weather causes substantial adverse socio-economic impacts by damaging and disrupting the infrastructure services that underpin modern society. Globally, $2.5tn a year is spent on infrastructure which is typically designed to last decades, over which period projected changes in the climate will modify infrastructure performance. A systems approach has been developed to assess risks across all infrastructure sectors to guide national policy making and adaptation investment. The method analyses diverse evidence of climate risks and adaptation actions, to assess the urgency and extent of adaptation required. Application to the UK shows that despite recent adaptation efforts, risks to infrastructure outweigh opportunities. Flooding is the greatest risk to all infrastructure sectors: even if the Paris Agreement to limit global warming to 2°C is achieved, the number of users reliant on electricity infrastructure at risk of flooding would double, while a 4°C rise could triple UK flood damage. Other risks are significant, for example 5% and 20% of river catchments would be unable to meet water demand with 2°C and 4°C global warming respectively. Increased interdependence between infrastructure systems, especially from energy and information and communication technology (ICT), are amplifying risks, but adaptation action is limited by lack of clear responsibilities. A programme to build national capability is urgently required to improve infrastructure risk assessment.This article is part of the theme issue 'Advances in risk assessment for climate change adaptation policy'.

Turning risk assessment and adaptation policy priorities into meaningful interventions and governance processes.

The UK is one of the first countries in the world to have set up a statutory system of national climate risk assessments followed by a national adaptation programme. Having this legal framework has been essential for enabling adaptation at the government level in a challenging political environment. However, using this framework to create an improvement in resilience to climate change across the country requires more than publishing a set of documents; it requires careful thought about what interventions work, how they can be enabled and what level of risk acceptability individuals, organizations and the country should be aiming for.This article is part of the theme issue 'Advances in risk assessment for climate change adaptation policy'.