Carmen Bunzl - Universidad Pontificia Comillas

Chapter 3. Implications of future climate regime architectures 149
Under a stabilization target of 450 ppmv CO2eq., the Multistage approach
was clearly the most permissive. In this case – under a stabilization target of 550
ppmv CO2eq., there is not that much difference between the Multistage
approach and the other approaches; in 2020 they would require similar efforts.
The CDC approach would be, after the Multistage approach, the next least
demanding for developing countries. This is logical: global emissions are fixed,
the most demanding approaches for Annex I regions will be the most
permissive approaches for non-Annex I regions.
The large differentiation between non-Annex I regions has previously been
noticed. In 2050, under a stabilization target of 450 ppmv CO2eq., the REEU
would have to reduce their emissions below 1990 levels. Another subgroup
could be Latin America, the Middle East and Centrally Planned Asia, which in
2050 their emissions would have to be close to their 1990 levels. Specially Africa
and South Asia are left with more space to grow since 1990. However, on the
other hand these regions have higher baseline scenarios, therefore their
reduction effort would be more or less comparable.
2.2.3 650 ppmv CO2eq.
Figure 7 provides the change in emissions from 1990 to 2020 and 2050 aiming
at 650 ppmv CO2eq. concentration for each region according to the various
approaches.
- Annex I regions
The reduction efforts required are much smaller than in the other cases. In
2020, they would only have to reduce between 0% and 15%; in 2050, emission
reductions would need to be between 25% and 75%. The USA would even be
allowed to increase their emissions compared to 1990 levels.
Escuela Técnica Superior de Ingeniería ICAI Carmen Bunzl Boulet Junio 2008