[en] Starting from a set of clear key assumptions on economic activity, population and hydrocarbon resources, WETO describes in detail scenarios for the evolution of World and European energy systems, power generation technologies and impacts of climate change policy in the main world regions or countries.It presents a coherent framework to analyse the energy, technology and environment trends and issues over the period to 2030, focusing on Europe in a world context. Three of the key results of this work are: (1) in a Reference scenario, i.e.if no strong specific policy initiatives and measures are taken, world CO2 emissions are expected to double in 2030 and, with a share of 90%, fossil fuels will continue to dominate the energy system; (2) the great majority of the increase in oil production will come from OPEC countries and the EU will rely predominantly on natural gas imported from the CIS; and (3) as the largest growing energy demand and CO2 emissions originate from developing countries (mainly China and India), Europe will have to intensify its co-operation, particularly in terms of transfer of technologies. The analysis of long-term scenarios and a particular attention to the energy world context, is an important element for efficient energy, technology and environment policies towards a sustainable world