CO2 budgets for municipalities - An introduction

Lecture 1: Current status of CO2 emissions

Learning objectives

At the end of this lecture, you are expected to be able to

  • Explain what a CO2 budget is
  • Describe the basic content of a CO2 budget
  • Describe how CO2 budgets may be used

First some basic concepts

  • A CO2 budget (carbon budget) is the upper limit of CO2 emissions in order to remain below a specific average global temperature
  • The global CO2 budget can be split in space and time
  • Please note that CO2 emissions are to a great extent accumulated in the atmosphere. This means that overspending one year has to be compensated the following years
  • CO2 budgets are considered to be an attractive analytical tool for a wide range of climate change analysis
  • Greenhouse gas emissions are usually expressed in CO2 equivalents
  • 1 kg carbon (C) = 3.664 kg carbon dioxide (CO2)

Anthropogenic perturbation of the global carbon cycle

Source: Global Carbon Project (2019).


The bold lines are scenarios that will be analysed in CMIP6 and the results assessed in the IPCC AR6 process.

Source: Global Carbon Project (2019)

Top emitters: Fossil CO2 Emissions

Source: Global Carbon Project (2019)

Content of a CO2 budget

  • Curren status
    • Emissions, goals and targets
  • Pathways to net zero emissions
    • Sector pathways, sectoral goals, KPI
  • Monitoring
  • Around 13 % of the Swedish municipalities have established CO2 budgets. Additional 25 % have started their preparations

Reporting of CO2 emissions

UN framework convention on climate change (UNFCCC)

  • The united nations entity supporting the global response to climate change
  • Has nearly universal membership (197 parties)
  • Is the parent treaty of the 2015 Paris agreement, and the parent treaty of the 1997 Kyoto protocol and its Doha amendment, adopted in 2012.
  • EU member states reports yearly emissions to UNFCCC. Sectoral data according to the IPCC classification are also delivered

EEA Greenhouse Gas – Data Viewer

Link to EEA Greenhouse Gas Data Viewer

  • You can download data in excel format for
    • Year 1990 – 2019
    • Single or multiple countries
    • IPCC sectors
    • Aggregated sectors
    • Different GHG (Greenhouse gases)
  • Good to know
    • LULUCF (Land Use, Land Use Change and Forestry)
    • Negative values = Carbon sink

EU targets

Fixed percentage annual reduction

  • We have actual emission values for the period 1990 – 2018 and emission goals for 2020, 2030 and 2050.
  • We need a goal model specifying the annual change in emissions in order to reach the overall emission goals. One simple goal model is to assume a fixed annual reduction in percent. This model may be formulated as

EU27 emission graphs with targets

Swedish targets (2017)

  • By 2020, 40% cut in greenhouse gas emissions (from 1990 levels)
  • By 2030, 63% cut in greenhouse gas emissions (from 1990 levels)
  • By 2040, 75% cut in greenhouse gas emissions (from 1990 levels)
  • By 2045, 85% cut in greenhouse gas emissions (from 1990 levels)

Local Emission Data

  • Swedish Emission Database
  • Statistics can be presented as maps (km2 grid), diagrams (national and county levels) and spreadsheets (national, county and municipal levels)
  • I have not investigated where to find local emission data for other countries

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