Following on COP 15 through 17, the world is moving towards a post-Kyoto Protocol era in which all of the nations of the world will be expected to contribute to decarbonising the global economy. This stems from increased recognition that if developed nations decarbonise, but developing nations remain on their current trajectories of growth of carbon emissions, it will not be possible to achieve the climate change targets set internationally (a less than 2 degrees C rise in mean global temperature, translating roughly into a doubling of the pre-industrial revolution levels of carbon dioxide in the atmosphere).
The model used in the Developed-Developing Nations project is shown above. It consists of a series of coupled zeroth and first order differential equations solved in the STELLA software.
While this certainly is the case, it also is the case that the developed nations have a special responsibility to not only decarbonise their own economies, but to help with decarbonisation of the developing nations. This is both a matter of equity, justice and fairness on the one hand, and of economic and political reality on the other. The populations of developing nations are deserving of increased access to the world's resources and economic growth, raising those populations out of poverty and all of the public health problems that come with poverty. The key is in sustainable growth, which means a significantly lower carbon intensity (carbon dioxide released per unit of Gross Domestic Product or GDP). Hence the need to find a path forward in which (i) the developed nations decarbonise, (ii) this decarbonisation produces technology innovation and drives down costs of technologies so they become feasible for the developing nations to adopt and (iii) finance, knowledge and institutional capacity flow from the developed to developing nations to support adoption.
Finding this path requires understanding not only the trajectory of emissions reduction in the currently developed world, but the trajectory that must be achieved in the developing nations as the emerging Durban Platform is defined and put in place.
To contribute to this process, 4CMR is using a completely open-source, communal, simple to operate, flexible computer model to identify the different pathways through which these goals can be met. The intention is not to specify which policies, mechanisms, instruments, etc will be needed, but rather how specific features of the climate problem (per capita emissions, population size, efficiency of energy use, land development, etc) might be configured to reach the international policy target mentioned at the top of this page.
The model consists of several sub-models:
- A Carbon Cycle sub-model, shown in green
- A Population sub-model shown in purple
- An Energy Systems sub-model shown in orange
- A Land Use sub-model shown in yellow
The model contains components for Developed Nations and Developing or Underdeveloped Nations in regard to the Population sub-model and the Energy Systems sub-model. The Land Use sub-model and the Carbon Cycle sub-model are global rather than region-specific. In the uses of the model in this project, the Radiation Balance function is disabled because we are focused on global atmospheric carbon as the policy target. Throughout, the units of estimates are billions of metric tons (BMT) of carbon in the atmosphere, and all other units are scaled accordingly. We follow only carbon (not all greenhouse gases), in whatever form the carbon appears in the carbon cycle.
A representative result is shown in the figure below.
Curve A is the Baseline, with no policies introduced; Curve B is with only population control introduced globally; Curve C is with policies reducing growth in per capita energy demand in the developed nations also introduced (on top of the population control of Curve B; it is largely hidden under Curve D); Curve D is with policies reducing the carbon intensity of energy provision in the developed nations also introduced; Curve E/F is with policies reducing growth in per capita energy demand in the developing nations also introduced, with policies reducing the carbon intensity of energy provision in the developing nations also introduced and policies affecting land use introduced globally.
D. Crawford-Brown and S. LaRocca, “Teaching Systems Principles and Policy Applications Using a Reduced-Scale Global Warming Model”, Journal of Geoscience Education, 54, 101-120, 2006.
D. Crawford-Brown, “Assessing the Sensitivity of Climate Change Targets to Policies of Land Use, Energy Demand, Low Carbon Energy and Population Growth”, Journal of Environmental Protection, 3, 12, 1615-1624, 2012.