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Mapping climate vulnerability in West Sussex

Climate change is already impacting West Sussex, and we know that it often disproportionately affects vulnerable communities. To better understand the relationship between social and climate vulnerability, WSCC partnered with the University of Brighton to develop the Climate Vulnerability Index (CVI). This tool uses geospatial demographic and environmental data and a unique indexing methodology to identify which communities in West Sussex are relatively more vulnerable to climate change impacts. This data can help ensure that resources and interventions are allocated in response to the specific challenges and vulnerabilities faced by each community, thus advancing a place-based approach to climate adaptation.

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The challenge

West Sussex County Council adopted a Climate Change Strategy in 2020 that sets out our goals to be a carbon neutral and climate resilient organisation by 2030, acknowledging the threat that climate change poses to residents, infrastructure, and council operations. While carbon emissions can be measured and reduced through decarbonisation programmes, achieving climate resilience is a more challenging target enlarged by the county’s diverse demographics, geology and geography – all of which means every community faces unique climate threats.

As we begin work to adapt our assets and services to withstand new environmental conditions, and help communities to do the same, it is vital to achieve consensus on what it means for West Sussex to be climate resilient. Without understanding how we are vulnerable, adaptation work will threaten to be piecemeal and inefficient.

The solution

To understand and quantify the potential risks posed by climate change, WSCC partnered with the University of Brighton to develop the Climate Vulnerability Index (CVI). The CVI is a geospatial mapping tool that contains information about the population (social, demographic, housing, health, and deprivation variables, for example) and environment (climate projections, flood zones, air pollution, and land cover, for example) across West Sussex.

The CVI includes 40 individual data layers for each Lower Layer Super Output Area (LSOA) in West Sussex. Together, each LSOA in the county is ranked relative to the others across all 40 layers, with the results indexed to provide a Climate Vulnerability score. This score suggests which communities may be relatively more vulnerable (i.e., those with a score closer to 1) to climate change based on social vulnerability, ability to adapt and respond, and environmental threat levels.

The impact

The CVI will aid in decision making and planning across the county with climate change and community vulnerability in mind. It makes clear the link between social vulnerabilities, such as health, income and age, and the compounding risks that climate change poses on communities that demonstrate one or more of those characteristics.

The CVI will ensure that appropriate interventions are considered given the unique risks faced by different areas of the county. If we know that areas of the county are more vulnerable to future flooding and we can also observe those same communities have less land covered in natural vegetation, for example, then we can identify nature-based flood risk management solutions as key strategies to address climate vulnerability in that area and seek appropriate partnerships and funding opportunities to do so. Moreover, we can pinpoint communities that may benefit the most from these interventions – such as areas with lower median income, more residents with disabilities or underlying health conditions, or less access to personal vehicles. This tool will also help build stronger business cases for investments and interventions in specific locations based on vulnerability, need and the anticipated impacts of climate change (e.g., the development of local area energy plans).

In these ways, the CVI demonstrates the far-reaching impacts that climate change will have and illustrates how all services across the county council and partner organisations will have a critical role to play in supporting climate action in West Sussex.

Lessons learned

To support the development of the CVI, we partnered with the University of Brighton to host two master’s placement students concentrating on environmental applications of geospatial analysis. We found the collaboration valuable because it provided the additional capacity and technical skills needed to gather and analyse the data in a timely manner.

Outside of this partnership, we have found that the CVI is a critical engagement tool for communicating about climate change both internally and externally. It offers a way to visualise where and why vulnerability exists across the county and provides information to help proactively address those risk factors in local planning, long-term strategic planning and developing partnerships. For example, among WSCC services for which climate change has not always been a primary consideration, the CVI has facilitated meaningful conversations about the role that everyone plays in climate action and has been a powerful visual tool to engage with political and executive leadership.


David Sale, Climate Change Policy & Partnerships Manager

Email: [email protected]