Energy is central to addressing major challenges of the 21st Century, challenges like climate change, economic and social development, human well-being, sustainable development, and global security. In 2005, Prof. Bert Bolin, the founding Chair of the Intergovernmental Panel on Climate Change (IPCC), with other eminent scientists and policy-makers, identified that a comprehensive, science-based assessment of the global energy system was needed if these challenges were to be realistically addressed. The Global Energy Assessment (GEA) is the result of this shared vision.

Since the establishment of the GEA in 2006 by governing Council of the International Institute for Applied Systems Analysis (IIASA), 500 independent experts (about 300 authors and 200 anonymous reviewers) from academia, business, government, intergovernmental and non-governmental organizations from all the regions of the world have contributed to GEA in a process similar to that adopted by the IPCC.

The final GEA report examines: (a) the major global challenges and their linkages to energy; (b) the technologies and resources available for providing adequate, modern and affordable forms of energy; (c) the plausible structure of future energy systems most suited to addressing the century's challenges; and (d) the policies and measures, institutions and capacities needed to realize sustainable energy futures.

Undertaking such a massive assessment has required extraordinary leadership, intellectual input, support and coordination. Governance of the Assessment has been overseen by the GEA Council, led by two Co-Presidents, Ged Davis and Jos é Goldemberg and comprising members of supporters and sponsors of the GEA, including international organizations, government agencies, corporations, and foundations and non-governmental organizations.

Today the world of energy has many of the features established in the 20th century:

– Energy consumption grows on average at 2% per year, most of it (80%) originates in fossil fuels

– Energy growth is driven by population growth and economic growth, now predominantly in developing countries and high levels of consumption in the developed countries

– 3 billion people don't have access to basic energy services and have to cook with solid fuels

However, the present path of uninterrupted reliance on fossil fuels poses four challenges to sustainability:

– Soaring greenhouse gas emissions

– Decreasing energy security

– Air pollution at the local and regional levels with resulting health problems

– Lack of universal access to energy services

Most reviews of the energy system needed for the 21st century start with “business as usual” futures and then analyze the effectiveness of specific corrections of course. For many the preferred options are technological fixes such as such as carbon capture and storage (CCS), nuclear energy and even geo-engineering schemes. However, to achieve sustainable development all the needed attributes of energy services, that is availability, affordability, access, security, health, climate and environmental protection, must be met concurrently. The Global Energy Assessment (GEA) accepts this and is unashamedly normative, examining future energy pathways that point to new solutions. The aspirational goals in GEA are defined as:

– Stabilizing global climate change to 2°C above pre-industrial levels to be achieved in the 21st century

– Enhanced energy security by diversification and resilience of energy supply (particularly the dependence on imported oil),

– Eliminating household and ambient air pollution, and

– Universal access to modern energy services by 2030.