Having identified a problem in Problem definition, this step concerns the exploration of the underlying causes of this problem and gaining preliminary insight in their severity. With regards to climate change in Europe, five climate threats can be distinguished:
Having a clear Problem definition is essential for this step, as this determines what climate changes relate to the problem. Climate changes can be labeled a threat or not, depending on the defined problem at hand. Identifying the climate threats that might impact the city or asset requires an understanding of local circumstances such as geography, past extreme events and local/regional climate projections. This information needs to be available to successfully finish this step.
The outcome is a list of climate threats that could potentially affect the city or asset, including a description of local historical events (frequency and severity) and a first insight in future occurrences (likelihood and potential impact), resulting in a first indication of the risk of a threat.
To start identifying climate threats, one could gather data on recent and historic hazard events in the city. The city administration or asset manager can gather information themselves, making use of the various tools that are available (see below), or they can hire experts and consultants, e.g. universities and knowledge institutes, to help them identify relevant threats. Be aware that you will need to consider hazards both from a current and future perspective – both are necessary. The current perspective is based on records and experience of hazard events, while the future perspective is where future climate scenarios need to be introduced.
Information about past occurrences of the hazards and the past trends regarding the relevant drivers should be ‘easily available’. If you are lucky, the environmental department within the city or of superordinate administrative levels will be able to provide information such as:
- the historical return periods (expected frequencies) of the respective hazards,
- the past intensities (e.g. high water marks, precipitation in l/sqm/h, wind forces (1-12)),
- the past recorded impacts,
- all available hazard, vulnerability and risk maps (done with historical and current data).
Aside from historical information, initial information about expected future climate change-related developments should be collected. Climate change can increase the probabilities, intensities and, hence, the risks of the identified hazards happening. We term climate-related trends as drivers and they generally include: sea-level rise, increased temperatures, lack of precipitation, increase of precipitation, carbon dioxide fertilisation. For each of the climate threats that are deemed relevant for the problem, a initial estimate should be drawn up for:
Probably, such information has already been acquired within the city departments or at regional level. Experts from city departments or regional authorities may support you in checking if the existing information fits the purpose, or if updates or extensions would be adequate. Points of contact include the Environmental department, the Emergency department, and departments responsible for social and economic matters of your city as well as universities and knowledge institutes.
If this information is not available yet, workshop(s) can be organised with experts determining the potential (but realistic) impact of the scenarios. In these workshops one looks for the attendance of:
- Managers of critical infrastructure of at least the types of infrastructures that are likely to be affected by the threat
- Crisis managers
The step will result in an overview of the expected risk due to each of the threats (e.g. in terms of: none, low, intermediate, high).
Bratislava’s climate threats
In Bratislava, majority of the information used for vulnerability assessment was coming from the statistical yearbooks of the Capital of the Slovak Republic Bratislava, which is published by the Statistical Office of the Slovak Republic. For additional information it is often necessary to contact the national or regional authorities that deal with monitoring climate change related indicators, such as anomalies in weather, history of natural hazards (such as floods, extreme weather events, droughts, etc.) historical records and forecasts on city demographics, economic development and critical infrastructures, natural resources, land-use and urban environment. You can also contact universities or research institutes in your city (but also outside your cities) and ask for opensource research results or publications or other information that may help you compose of basis of knowledge for your case. By approaching these different actors your also start building your stakeholder network. Their participation is an extremely important aspect in the later stages of the adaptation process.
Paris’ climate threats
The City of Paris identified 12 types of impacts affecting it. Eight of them are climate hazards, whilst four are related to resource scarcity. In addition, 13 sectors which are or may be impacted were identified. The results showed that so far Paris’ critical infrastructure systems have worked reliably and have shown to be resistant towards past extreme weather events. But climate change and resource scarcity, combined with urbanization and an increase in population density vigilance must be paid where parts of the city wide system appear to be more vulnerable than others. Five major issues emerged:
- Heat waves, which may possibly exacerbate the urban heat island effect
- Floods , following heavy rains, run-off or flooding from the Seine River
- Droughts, which may impact on the city’s water sources, notably from 2050 onwards
- Pressures on food and energy resources
- Biodiversity preservation throughout the city preservation
The study by the City of Paris called for further in-depth studies on health risks caused and aggravated by climate change impacts and a deteriorating air quality, on the robustness of the insurance system of the city administration, residents and companies who are being affected by these impacts as well as on how climate change is leading people to migrate elsewhere (Mairie de Paris, 2012).
Greater Manchester’s climate threats
Risk assessments are central to adapting and building resilience to climate change. The concept of risk is established within the climate change community, and climate change risk assessments are undertaken within the public and private sectors.
- Improve understanding of the potential implications of climate change for its critical infrastructure.
- Prioritise themes for adaptation and resilience strategy and action, and the investment of related capacity and resources.
There are four key elements to the risk assessment approach followed within the GM case study:
- Identify extreme weather and climate change impacts to critical infrastructure
- Determine likelihood of weather and climate change hazard occurrence
- Assess the consequences of weather and climate change impacts for critical infrastructure
- Assess weather and climate change risk to critical infrastructure
Supporting tools and methods
Detailed, step-by-step description of steps to take intended to provide a methodology to carry out a first assessment and keep track of the climatic changes in a city and to understand how these changes will impact the urban and social fabric.
The RAMSES ‘Determining key climate risks for cities’ worksheet is a step-by-step description of steps to take to identify the main risks facing your city.
INTACT Extreme weather maps
The INTACT ‘Extreme weather maps’ page represents an on-line visual map of the expected change in 47 weather indicators for temperature, precipitation, wind and combinations thereof for the short (-2040), mid- (-2070) and long-term (-2100) period. The data encompassess a roughly 30x30km grid over all Europe.
Footnotes [ + ]
|2.||↑||Future scenarios for this climate threat are not available.|
|3, 4.||↑||The year 2050 has been chosen to provide a long term outlook on the effect of this climate threat.|