|
|
About our data
Reporting environmental and social data differs from reporting financial data in a number of important ways. There are inherent limitations to the accuracy, precision and completeness of environmental and social data. These limitations stem from the nature of these data. Certain parameters rely on human behaviour and so are affected by culture and personal perception. Other parameters rely on complex measurements that require constant tuning. Still others rely on estimation and modelling. We accept that our published environmental and social data will be affected by these inherent limitations. We continue to improve data integrity by strengthening internal controls. Safety and environmental data are collected from companies and joint ventures where we have a controlling interest and certain companies to which we provide operational services. These data are reported on a 100% basis, regardless of our equity share in the company. Operations that were acquired or disposed of during the year are included only for the period of time we had ownership. In some cases, data for companies where control changed hands during the year, for example Sakhalin Energy, were included for the entire year, as this was needed to allow consistent comparison of performance trends at company level. Other data are collected from external sources, staff surveys and other internal sources as indicated and reported.
We only include data and events, like safety incidents, that have been confirmed by the time this publication goes to print. If incidents are reclassified or confirmed after publication, the data is restated in the next year’s publication.
Data marked 
in the social data table is obtained from an internal survey completed by the senior Shell representative in each country. The degree of accuracy for this is significantly lower than for data obtained through our financial systems.
We set internal improvement targets for our key safety and environmental parameters and have longer-term public targets for energy efficiency in our chemicals plants, for eliminating the disposal of gas by continuous flaring, and for reducing greenhouse gas emissions from our operations.
Unless otherwise noted, estimates of the number of homes served, or cars fuelled by our activities, throughout this report are based on the average electricity consumption of a household in Europe and the fuel efficiency and petrol tank size of a typical small car (Ford Fiesta).
Conversions into US dollars are based on the average rate for the year 2007.
1
