Change happens. People can sense change but science can measure it and might be able to predict its future. A scientific model would be a beautiful help for us to understand the behavior of both the global economy and the Earth's climate. The International Energy Agency (IEA) has been developing the WEM-ECO model for that purpose.* This model is certainly a beauty resulting from the dreams of our humanity.

Humbling to note first that we are equipped now with the essential scientific tools to study the Earth's climate within the context of our many activities. In a perfect world, we can make our decisions about the global economy or energy or climate change within the certainty limits of our reliable mathematical models. Our governments can work with our experts and discuss the possibilities in the  horizon. Long-term scenarios can be tested against expert opinions and new data.

The World Energy Model (WEM) has been developed at IEA internally since 1993 and is now in its Version 10. Most of its data are obtained from the IEA's own databases of energy and economic statistics. External data sources are also available to draw from. This model is used annually to simulate global energy scenarios extending to the year 2030.

The WEM is made up of six main modules: 1. Final energy demand, 2. Power generation, 3. Refinery and other transformation, 4. Fossil fuel supply, 5. CO2 emissions, 6. Investment. Complete energy balances are compiled at a regional level; the CO2 emissions and energy supply investment are then calculated using carbon factors. I mention this much detail to indicate its climate connection.

Recent efforts at IEA have been focused on developing a flexible hybrid model (WEM-ECO) by coupling their WEM with IMACLIM-R by means of a unique architecture. WEM is a bottom-up and technology-rich model while IMACLIM-R is a top-down and general-equilibrium model. Challenges in the integration of a large bottom-up model with a general equilibruim model  are discussed in the paper along wth the coupling technique utilized for the desired knowledge capture from the organization's experts.

The driving force was to incorporate expert judgment in an integrated economic and energy-based framework for decisions regarding the climate-change scenarios. The model's architecture was designed to bring in expert judgment on trends and yet to facilitate computation convergence towards a common set of internally-consistent scenarios.

The WEM-ECO model was used to generate the Reference and High Growth scenarios of the IEA report World Energy Outlook 2007. The model's "architecture makes it possible to capture and formalize analytically the expert knowledge embodied in the IEA organization and network." The reference paper* describes how the architecture helps achieve convergence towards a common set of internally-consistent scenarios.

World Energy Outlook 2008 will be released by IEA in November 2008. If the WEM-ECO makes in this report additional contribution to our understanding of our world of energy, economy, and climate, it would be a beauty that keeps on giving like the WEM.

* IEA paper: "A Hybrid Modeling Framework to Incorporate Expert Judgment in Integrated Economic and Energy Models – The IEA WEM-ECO model," Fabien Roques and Olivier Sassi, Economic Analysis Division, International Energy Agency, Paris, France, 2007.