Carmen Bunzl - Universidad Pontificia Comillas

Chapter 2. Options for future climate change architectures 71
2.1.4.1 Environmental effectiveness
An environmental effective approach must ensure that stringent global
emission targets are reached. It should include greenhouse gas emissions from
all important sources and sectors and avoid leakage (instead of reducing
greenhouse gas emissions, transferring these emissions to other sectors or
countries). It should also provide certainty about future emission levels.
The Contraction and Convergence and the Tryptich approaches ensure
environmental effectiveness best, if all countries comply with the emission
targets. Stringent concentration levels, such as 450 ppmv CO2 could be reached.
Leakage would be avoided since all countries would participate.
The Multistage approach would eventually include all major developing
countries, but only when a certain threshold is passed. Only if Annex I
countries decrease emissions substantially and developing countries participate
relatively early in time, stringent stabilization levels could be reached. Leakage
of emissions to non-participating countries could occur; if the threshold is based
on per capita emissions, the prospect of having to apply an emission limitation
target may be an incentive not to increase emissions in these countries.
Another environmental criterion to take into account may be the approach’s
encouragement of early action, those countries that do not have yet binding
commitments to keep current emissions as low as possible.
The Contraction and Convergence approach encourages countries to
undertake early action, since less reductions would be necessary afterwards or
even excess emissions allowed.
In the Multistage approach, having low per capita emissions is always an
advantage, as it keeps them from moving to higher steps and to stricter targets,
therefore early actions are encouraged. Non-participating countries would have
incentives to decrease their emissions by participating in the CDM. However, if
the targets are based on an emission level in the future, some countries may not
Escuela Técnica Superior de Ingeniería ICAI Carmen Bunzl Boulet Junio 2008