CADI, Climate-Driven Agricultural Decline Index

The index was built by Laura Mayoral, Hannes Mueller, Björn Komander and János Szentistványi, from the Institute for Economic Analysis (IAE-CSIC), the Barcelona School of Economics, IIIA-CSIC, RMIT University Melbourne and IDEA.³

For each grid cell of about 10 km, the project uses the Global Agro-Ecological Zones model (GAEZ v5) to compute attainable yield: the most a location could produce under its biophysical conditions.^1,2 The crop mix in each cell is held at the baseline, so only climate varies and no adaptation is assumed.¹ Attainable production of the main crops is converted to calories and reported as the number of people a cell could feed each year at 2,000 calories a day.¹

Observed change compares the 1981–2000 climate with 2001–2020, using the AgERA5 weather dataset.¹ Projections run from 2021 to 2100 against the 2001–2020 baseline, using two IPCC scenarios, SSP3-7.0 and SSP5-8.5 (standard pathways of future emissions and development).^1,2

Results are shown in an interactive map explorer that has a slider over time periods and switches between observed and projected change, and between absolute and percentage values.² The site, aimed at policymakers, development practitioners and researchers planning adaptation, offers no download, licence or API for the underlying grid.^1,2

The team reports that more than 640 million people live in farming areas where the number of people that can be fed has fallen by more than 10% over 30 years.^1,4 By 2041–2060 under SSP3-7.0, about 49% of the world's population would live in cells with at least a 5% decline.^1,4 A full paper is forthcoming.⁴