Carmen Bunzl - Universidad Pontificia Comillas

Chapter 3. Implications of future climate regime architectures 153
Assumes action by developed country first and delayed action by developing
countries. Hence, the reductions necessary for Annex I under these approaches
are higher in 2020 than for other approaches.
However, when chosen such a stringent stabilization level as 450 ppmv CO2eq.,
developing countries participate early (most of them by 2020); and there is not
much difference between the approaches.
Multistage
The setting used for this approach, leans even more toward reductions by
Annex I countries and delayed reductions by non-Annex I countries.
This is evident in the 450 ppmv CO2eq. scenario results; the multistage
approach leads to the most different regional emission allowances compared to
the other approaches.
The choice of parameter values is subjective. Lower stage-thresholds, for
example, would require higher contributions of developing countries.
Sectoral approach
With the number of sectors included in these calculations, it is very difficult to
achieve the necessary reductions, parameters are very stringent.
All sectors would have to be included to stabilize at a low level such as 450
ppmv CO2eq.
Looking broadly at the results across the approaches, it can be observed that
significant reductions below 1990 levels for all approaches and stabilization
levels are necessary from developed countries in addition to early deviation
from reference in developing countries. The necessary reductions across the
approaches are summarized in Table 3 - 4.
Escuela Técnica Superior de Ingeniería ICAI Carmen Bunzl Boulet Junio 2008