Analysing costs & benefits, building scenario and interpreting results
Climate Budget Training Course: Module 4
This module deepens climate budgeting by examining how to assess the financial costs and benefits of climate actions compared with business-as-usual scenarios. Participants explore different impact assessment methods used by cities of Tampere, Aarhus and Norderstedt, including cost-efficiency and cost–benefit analyses, and learn how these calculations are impacted by different scenarios. The module also demonstrates how results can be visualized and explained in an accessible way – ensuring that complex financial insights effectively support informed decision-making, with the Climate Action Decision Support (CADS) Tool developed in the Climate-4-CAST project.
Recording of the training
Overview of the Module 4 presentations
Short overview of the Climate-4-CAST project and the training course
The session started with a short overview of the Climate-4-CAST project and the training course by Donald Alimi and Olena Zinchuk. Climate-4-CAST is a three-year project developing an open-source solution with ten project partners involved. One of the key challenges it addresses is how cities can turn climate commitments into concrete actions despite limited budgets and capacity. The Climate Action Decision Support (CADS) Tool developed and piloted in the project helps cities to compare different actions scenarios.
Climate budgeting: approaches to action assessments
The presentation by Kim Tatum, HafenCity University Hamburg, focused on climate budgeting approaches and action assessments. The emphasis was placed on the financial aspect of climate action and how cost-benefit analysis can support decision-makers. The Climate Action Decision Support (CADS) Tool was introduced as a way to provide cost projections, timelines for expenses, cost-efficiency information, and estimates of savings or benefits. An important point from the presentation was that the purpose of the analysis should always be clearly defined first: what needs to be assessed, for whom, and for what type of decision-making process. It was also noted that decision-makers often want clear numerical results, even when data collection and precision remain challenging.
Another important topic was operationalising climate budgeting approaches. The presentation highlighted the need for negotiations when turning mitigation strategies into concrete measures and the importance of keeping climate budgeting aligned with annual budgeting processes. It was also emphasised that impact assessment modelling is directly connected to monitoring processes. One of the key takeaways from this session was to start with smaller assessments and gradually expand over time while ensuring that the output matches the needs of decision-makers.
Climate Action Decision Support (CADS) Tool functionalities on scenario changes and visualisation of results
Michael Mechenich from Kausal Ltd. demonstrated the functionalities of the CADS Tool, particularly regarding scenario changes and visualisation of results. The presentation showed how the tool allows users to explore a city’s emissions inventory and forecasts visually and how different scenarios can affect outcomes. The tool includes parameter sliders that allow baseline quantities and action impacts to be adjusted instead of relying on single fixed values. It was explained that actions can be compared using indicators such as cost-efficiency and total emissions impact.
Actions’ impact assessment methods and outcomes: city case examples
Tampere
Emmi Nieminen presented City of Tampere’s experiences with climate budgeting and the CADS Tool. She explained that Tampere has used a climate budget for seven years as a governance and reporting tool to monitor how much money is spent on climate action. Different assessment methods were introduced, including direct cost calculations, cost-benefit analysis, and cost-effectiveness analysis. The presentation particularly focused on sustainable modal shift targets and how the tool can visualise costs and benefits related to different transport modes. It was emphasised that cost-effectiveness analysis is especially important because it helps cities compare climate actions consistently and identify the most economical emission reduction measures.
Aarhus
The City of Aarhus case was presented by Anders Rosenstand Laugesen and focused on cost-effective climate action planning through the use of shadow prices. Shadow prices were described as the cost per ton of CO2 reduced, allowing actions to be ranked according to their effectiveness. Different types of shadow prices were introduced, including budget-economic, time-corrected, and societal perspectives. The presentation also highlighted the importance of discounting rates and choosing the correct scope for calculations in order to produce useful results.
Norderstedt
Toya Engel presented a case example from Norderstedt, Germany, on replacing street lights with LED lighting. Different scenarios were compared, including continuing business as usual, replacing all lights with LEDs by 2029, and delaying the replacement due to budget limitations. The presentation showed how different investment decisions can influence costs and energy consumption over time.
The module concluded with an introduction to the next training phase on practical training, matchmaking, and mentoring exchange presented by Olena Zinchuk, UBC SCC.