“Carbon budgets” or “Climate-proofed budgets”?

Our new briefing helps cities navigate science-based targets approaches

When talking about how to align cities policies with the EU decarbonisation objectives, we often hear the words “science-based targets”, “carbon budgets” or “climate-proofed budgets”. How do these approaches work? What are the differences among them? How to implement them at local level?

We have just published a new policy briefing to answer these questions. The briefing includes some case studies, showing how different local governments in Europe successfully used such approaches.

Science-based targets are a set of goals to identify a clear route to reduce greenhouse gas emissions and keep global warming below 2°C from pre-industrial levels. Cities can use such targets to identify the most impactful actions and leverage on their own strengths.

Carbon budgets

Carbon budgets emerged as a scientific concept from the IPCC’s 2014 Synthesis Report on Climate Change and relate to the “cumulative amount of CO2 emissions permitted over a period of time to keep within a certain temperature threshold”. Much like a financial budget, a carbon sets out how much CO2 can be spent over a fixed period. Once gone it cannot be replenished, unless new technologies are rolled out at scale to extract CO2 from the atmosphere. This framing is used to inform local and national climate strategies using the 1.5°C or 2°C temperature targets as enshrined in international goals.

Climate-proofed budgets

At State level, some countries have started another exercise that can be complementary to the carbon budgeting approach. They assess their national budget with a “climate compass”. Measuring and following up on the evolution of the city’s GHG emissions is essential to identify the most polluting sectors and the most efficient mitigation measures. This helps prioritise investments and ensures that the city’s money is being spent in accordance with its commitments. Several cities have developed their own budgeting and reporting mechanisms with the objective of calculating CO2 emissions and putting climate-related data at the centre of the city’s strategic planning – aligning their investments and actions around the reduction of CO2 emissions.

What about the SECAPs?

The Sustainable Energy and Climate Action Plans (SECAPs), currently required when a city is committing to the Covenant of Mayors, are a less strategic: they are linked to medium-term planning of energy and climate related policies. Nevertheless, SECAPs are also founded on science-based targets. For their commitment to 2030 targets, cities are required to develop their 5 to 10 years’ action plans, representing thus a translation of the Paris agreement into local climate strategies.

Many approaches available to local authorities

Additional instruments & approaches can be used to fully integrate energy and climate issues into cities’ budgetary and financial planning:

  • Environmental reporting and budgeting
  • Green public procurement
  • Fossil fuel divestment of municipal funds
  • Green municipal bonds
  • Earmarking local revenues and other financial instruments

Read the briefing to learn more!

If you want to stay tuned and learn from other cities that have started to implement science-based target approaches, contact us. In the framework of the “Zero Carbon Cities” project, we will pilot such approaches in seven cities.



Claire Roumet

Publication date

May 29, 2020