The Threat of Climate Change - Energy and Climate: How to Achieve a Successful Energy Transition - page 32

Figure 3.3 Trend of CO 2 emissions in tonnes of carbon per year
(450 ppm and 550 ppm for CO 2 alone). In the first case, the temperature
increase estimated on the basis of the IPCC results would be 1.6 C and in
the second case 2.5 C [34].
If the CO 2 emissions were stabilised now (trend B), the CO 2 content in
2050 would be about 500 ppm. In practice, the possibility of stopping the
rise in emissions immediately would be unrealistic, and they are likely to
continue rising until 2020, even if we manage to slow down the rate of
increase. Emissions will then have to decrease to reach a level close to half
the current level by 2050, in order to respect the limit of an average
temperature rise of 2 C (trend C - scenario 450 ppm for CO 2 alone).
If the long-termobjective is to express the level of CO 2 emissions as a figure
per inhabitant in the world, which would seem fair, the emissions from the
industrialised countries must be reduced by a factor of about 4 by 2050, in
order to allow the emissions from the Third World countries and the
developing countries to increase. France has assigned itself this objective [35].
The current trend
Compared with these objective scenarios, the actual trend observed is
worrying. Current CO 2 emissions are in the region of 27 billion tonnes per
year due to the consumption of fossil fuels. Electricity production (39%),
industry (22%) and transport (23%) represent, at world level, the main
sources of CO 2 emissions related to human activities.