Session: Impact Assessment

Since the UNEP-EPA-CML workshop in 1999 in Brighton, a broad consensus has grown among LCA practitioners and methodology experts that it is desirable to “midpoint” approaches and “endpoint” approaches in a common framework, as both have their specific strengths and weaknesses. Within the frame of the ReCiPe Project (A cooperation between the Radboud university of Nijmegen, Centrum voor Milieukunde Leiden and PRé Consultants), an improved method for LCIA is designed in which category indicators can be chosen at the midpoint level or at the endpoint level. This paper describes the way the impact of climate change at midpoint and endpoint-level, on human health and ecosystems, is handled and implemented. The produced method is a follow up of the Eco-indicator 99 method, but totally novel of its kind. In comparison with the Eco-indicator 99 method it has a better framework, using state of the art developments in the field of environmental mechanisms associated to climate change. Furthermore, ecosystem damage endpoints are now included and the calculated human health damage is based on 5 health effects instead of 3 in the Eco-indicator 99 method.

At midpoint-level, the new IPCC equivalency factors are used to combine all different emitted gasses to one single CO2-equivalent score. At endpoint-level a more complex and new model is developed, that somewhat differs from the traditional structure “fate-effect-damage”. The usual fate step is not applicable to climate change and the effects are analyzed in a two-way procedure. First, a link between CO2–equivalents and temperature rise is made (temperature factor). Second, the relation between temperature rise and the impact on human health and ecosystems is calculated (damage factor).

The temperature factor describes the change in temperature caused by a certain emission during a certain time period. Almost all studies we found correlate an emission scenario (emissions per year) with a temperature change. For our project we need the link between an emission, expressed as mass load and a (temporary) temperature increase. We found this relation in the PHD dissertation of Meinshausen (2)(4), who analysed the effect of mitigation measures in a wide range of climate models.

The damage factor is different for human health and ecosystem damage. For human damage (DFHH) the marginal change in temperature is linked to marginal changes in DALY [daly/yr.°C]. The health effects considered in this study are malnutrition, diarrhea, cardiovascular diseases, malaria and, inland and coastal flooding. The data needed to calculate the damage factors for human health are derived from McMichael et al. (3). This report describes how health risks increase as a function of temperature increase for the different health effects in different world regions.

The damage factor for ecosystem damage (DFES) due to climate change links the marginal changes in temperature to marginal changes in disappeared fraction of species [PDF/°C]. The extinction factors needed are derived from the paper of Thomas et al. (5). This study predicts the extinction of species on a global scale using three different methods . The most specific calculation method, method 3, is chosen. Furthermore, it uses the area species relationship which is also used in land-use, and it is a compilation of several regional studies. It presents extinction risks, for global and local temperature changes, for several taxa and with or without adaptation (in the form of dispersal). Because a global scale effect is analysed, the global temperature changes are used.

To handle the model uncertainties arising in the step from temperature rise to impact effect, the cultural perspectives , as used in Eco-indicator 99, are applied in our calculations (1)(6).

As a result, characterization factors on both midpoint and endpoint level are produced. The endpoint characterization factors for climate change health damage and ecosystem damage, for three different cultural perspectives, are presented in the table underneath