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
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)