Cumulative effect on emissions

Greenhouse gases (especially CO₂) build up in the atmosphere. It is therefore important to consider the cumulative effects of emission trends. Having strong targets in the near future (e.g. the 42% by 2020 target) will make a significant difference on what we will have emitted by the end of the century.

This graph shows UK emissions target lines (in mega tonnes CO₂ [i] per year) that have been developed in the previous pages.

This next graph shows the same UK emission target lines, in giga tonnes CO₂ [i] , accumulated in the atmosphere over time.

If we follow the trend to meet the Kyoto target the UK will have emitted 75 billion tonnes of CO₂ since the industrial revolution (1800).
You can see that we will need further emission reduction targets after 2050.
Notice that the sharper emissions reductions to meet the "Intended cut" line make a significant difference in resulting cumulative CO₂ emissions by 2080. Whilst both Agreed and Intended cut lines meet the 80% reduction by 2050 target, there is a 2 billion tonne difference in the amount of CO₂ emitted by the end of the century.
Assuming the rest of the world follows Contraction & Convergence targets to match the UK, we would see global mean temperature rise by <1.9ºC (see Global temperature change page), if we follow the "Intended cut" emission target line, or >2.0ºC rise if we follow the "Agreed cut" line. Whilst this may sound like a small difference, it is important to consider that only fractions of a degree separate the different emission scenarios, for example: the Low emission scenario would be about 1.7ºC rise, and the Medium emission scenario would be about 2.6ºC rise.

Return to main Emissions Targets page