Global Greenhouse Gas Emissions Scenarios: Integrated Modeling Approaches

This paper reports on the findings of an international and interdisciplinary study that developed a new set of greenhouse gas (GHG) emissions scenarios with different modeling approaches. Long-term GHG emissions scenarios are an indispensable tool for the analysis of possible climate change and its impacts, as well as for crafting strategies to adapt to or mitigate against undesirable consequences. The challenges such analyses pose are enormous. They include dealing with planetary processes and highly non-linear systems, such as the global climate; addressing time scales of up to a century; dealing with the inherent uncertainties of the pervasive social, economic, and technological transformations that can be expected over such long time scales; analyzing the multitude of sources of a large variety of different GHG "species" and devising scenarios of how they might evolve in the future.