Long-term economic growth and environmental pressure: reference scenarios for future global projections

Future projections of the impact of international climate change (and other) policies are usually presented against a “business as usual” baseline or a reference scenario. As a wide range of possible factors can affect the economic growth projections, it is useful to depict a range of possible developments. This paper presents a set of global representative scenarios that may provide alternative perspectives on future socioeconomic developments and compare these scenarios in terms of their respective economic and environmental consequences. The scenarios are based on the Shared Socioeconomic Pathways (SSP) storylines developed by the Integrated Assessment Modelling Consortium (O’Neill et al., 2012). The different scenarios (i.e. SSP representations) are then framed in terms of how they affect different elements that influence growth, such as demographics, education and technology convergence. Given the long-term nature of some of the major environmental challenges, including climate change, the time horizon is 2100. This paper typically assumes a convergence process, though placing special emphasis on the drivers of GDP growth over the projection period rather than projecting convergence only on income levels. Based on this, long-term projections are made for key drivers of per capita economic growth (e.g. total factor productivity and human capital). Together with population growth, these drivers are then used to project GDP pathways for more than 175 countries, representing 98.5% of global GDP in 2010.