Countries displayed here were exemplarily chosen and represent industrialized (United States),
newly industrialized (Mexico) and developing (Botswana) countries.
Convergence & Contraction:
Approach developed by the
Global Commons Institute
. Main assumption is that countries' per capita emissions converge in a (freely selecable) convergence year.
Budget Approach:
Developed by
WBGU
. The global emissions budget is allocated on a per capita basis for all states.
Grandfathering Approach:
The budget is allocated to states proportionally to their base year emissions.
This approach is more or less implicitly adopted in most climate negotiations.
Besides the approaches displayed here, several other approaches exist, e.g. the
Regensburg Model
(Sargl et al.) or the
Extended Smooth Pathway Model
(Raupach et al.). Approaches displayed here were exemplarily chosen
In contrast to the other approaches, "Convergence and Contraction" relies not only on an emission budget,
but also on assumptions about future global emission paths. For the sake of example and simplicity,
a constant linear reduction of global emissions to zero is assumed, which is otherwise not realistic. A linear transition
from grandfathering to per capita emissions is assumed.
Data from the
Global Carbon Atlas.