ExternE is the well-known acronym for “External Costs of Energy” and a synonym for a series of projects starting from early 90s till 2005.
The so called “ExternE-Methodology” is an approach of calculating environmental external costs as it was developed during the “ExternE project-series”, called Impact-Pathway-Approach. The tool and data for calculating environmental external costs according to the Impact-Pathway-Approach have been implemented in the EcoSense model.
All the results of the “ExternE project-series” have been made available on the ExternE project webpage, which can be found here (Old version from 2006): http://www.externe.info/externe_2006
After 2005 there have been many other projects applying the tools but also further developing the tools towards a more and more “Integrated Assessment”. For example, during the NEEDS-project 2004-2008 the EcoSense model has been transferred into the web based tool EcoSenseWeb. To make the updates available, the web site you are currently visiting has been updated to include all relevant information till May 2012.