TODAY'S TECHNOLOGIES, TOMORROW'S DRIVING FACTORS:
THE THIRD WAVE OF EMISSION INVENTORIES

(TECNOLOGÍAS ACTUALES COMO LAS RESPONSABLES DE LAS EMISIONES DEL FUTURO:
LA TERCERA OLA EN LOS INVENTARIOS DE EMISIONES)

Once, there were global emission inventories and urban emission inventories, and they served different modelers. Air quality studies didn't need to communicate with global modeling-did they? That was the first wave of emission inventories.

Next, the atmospheric chemistry community noticed the significance of megacities, and urban modelers needed boundary conditions. They began talking about how to share emission information. Atmospheric field programs were planned with an emission component. The importance of people who know their countries and emission sources is being recognized. This critical knowledge should be linked, and someday a "best-of-everything" inventory will be available. We are in the second wave of emission inventories.

As we work to improve emissions, more knowledge needs become evident. For example, global inventories were once satisfied with a single emission factor for transportation emissions. Now, vehicle fleets are necessary. This improved representation demands a huge degree of detail which is rarely available. The dynamic nature of emissions is also quite apparent. Rapid growth or contraction, and changes in technology or emission standards, alter emission profiles in a region. When the collaborative, second-wave global emission representation is completed, it will be outdated.

We can move beyond this dilemma with the third wave of inventories. Inventory developers can share knowledge about the basic factors that affect emissions and their changes, rather than sharing only the emissions. First, today's technologies: What are the fractions of each type of emitter and how have those divisions come about? For example, how many vehicles have catalysts, and what fraction of those catalysts is working? Second, tomorrow's driving factors: What causes changes in the mix of emitting technologies? For example, what are vehicle retirement rates, and selection of new versus used vehicles? Other inventory developers in similar situations can use this information to improve their inventories given limited resources, and sharing this information within an appropriate framework can allow rapid forward projections.


Dr. Tami C. Bond.