Downscaling socioeconomic and emissions scenarios for global environmental change research: a review

Abstract

Global change research encompasses various scales from global to local. Impacts analysis in particular often requires spatial downscaling, whereby socioeconomic and emission variables specified at relatively large spatial scales are translated to values at a country or grid level. In this article, the methods used for spatial downscaling are reviewed, classified, and current applications discussed. It is shown that in recent years, improved methods for downscaling have been developed. 

Enhancing the relevance of Shared Socioeconomic Pathways for climate change impacts, adaptation and vulnerability research

“…Narrative downscaling is often a procedural step when developing downscaled quantitative scenarios (van Vuuren et al 2010). Having established the regional, local, and/or sectoral context to describe a set of alternative futures, those qualitative futures can be translated into quantitative indicators to facilitate subsequent analyses.…”

“…Although there is no shortage of conceptual approaches, no standardized methods exist to facilitate that translation, making the process somewhat ad hoc and subject to the needs of individual studies and normative assumptions. By building on the experience with the SRES scenarios (Grübler et al 2007;van Vuuren et al 2007), various statistical and model-based downscaling methods can be applied, assuming some a priori, coarse-scale quantitative metrics to generate regionalized quantitative scenarios for relevant assessment indicators (van Vuuren et al 2010). Although expedient, such approaches often develop scenarios for a limited suite of variables with little consideration of the broader socioeconomic context.…”

Building world narratives for climate change impact, adaptation and vulnerability analyses

“…For instance, other factors such as the consequences of the 2008 financial crisis may be more important for near-term vulnerability, e.g., up to 2030. Also, since climate change impacts and adaptation options are very context-specific and require local studies, global scenarios will need to be downscaled into local scenarios 41 . At a local scale, some factors that are secondary at the global scale may become dominant.…”

RCP 8.5—A scenario of comparatively high greenhouse gas emissions

“…The vast majority of downscaling approaches have traditionally employed proportional downscaling (van Vuuren et al 2010), where emissions of individual grid-cells are scaled following aggregate changes at the regional level. While proportional algorithms are simple to implement and easy to reproduce, they generally do not account for important local differences in efforts to reduce pollutant emissions.…”

“…Many scenario assumptions and outcomes of the RCP8.5 are thus derived directly from the co-called A2r scenario , which was selected from the literature to serve as the basis for the RCP8.5 (for an overview of RCPs, see van Vuuren et al (2011a), and for the RCP process and selection see Moss et al (2010), and IPCC (2008)). …”