Projected Exposure To Drought

The dataset provides a global assessment of projected changes of drought using the Standardised Precipitation Evapotranspiration Index (SPEI) across four climate scenarios (SSP 1-1.9 is currently not available for the SPEI). The SPEI presented here is a measure of integrated water deficit in a given area for the preceding 12 months and includes temperature-dependent evapotranspiration data. The SPEI over a 12 month period enables identifying long-term drought, where values between -1 and 1 are typically considered as normal conditions. A SPEI value between -1 and -1.5 indicates moderately dry, between -1.5 and -2 severely and lower than -2 extremely dry conditions. Please see the working paper for a more complete description of the methods.

The dataset also provides a global assessments of projected changes of drought using the maximum number of consecutive dry days and enables analysing short-term drought across five climate scenarios. This index is relevant for biodiversity, agriculture, forest and water management. In the context of agriculture, it is often used as a proxy for a lack of rainfall during a short period of time, which can quickly lead to dry conditions and thus it can help agricultural managers understand critical conditions.

The dataset spans the period 2015-2100 and provides anomaly estimates for the future time periods of 2020-2039, 2040-2059, 2060-2079 and 2080-2099, which are typically referred to by their midpoints as the 2030s, 2050s, 2070s and 2090s. The available climate scenarios include four Tier-1 Shared Socioeconomic Pathways (SSPs) that range from low to very high-emissions scenarios (i.e. SSP 1-2.6 [low], SSP 2-4.5 [intermediate], SSP 3-7.0 [high] and SSP 5-8.5 [very high]) and an additional very low-emissions scenario (i.e. Tier-2 SSP 1-1.9).

The dataset has a global coverage on a national level. On the sub-national OECD TL2 level, results are reported for all OECD countries as well as Serbia, North Macedonia, Bulgaria, Croatia, Albania, Romania, Liechtenstein, Montenegro, Cyprus, Malta, Peru, Brazil, Argentina, Russia, India, Guatemala, South Africa, Tunisia, Indonesia and China. On the sub-national OECD TL3 level, results are reported for all OECD countries as well as Montenegro, Croatia, Bulgaria, Albania, Romania, Cyprus, North Macedonia, Liechtenstein, Malta and Serbia. A number of aggregates are further included: Euro area, European Union, Advanced economies, Emerging market economies, G7, G20, OECD, OECD Europe, OECD Asia Oceania, OECD Americas and the LAC region.

Data source(s) : The indicator methodology and the underlying data sources are discussed in the OECD working paper Maes et al. (2025). The primary data sources include projected drought data from the Climate Change Knowledge Portal and cropland extent data from the European Space Agency Climate Change Initiative.

Contact : ENV.Stat@oecd.org