Explore historical and projected climate data, climate data by sector, impacts, key vulnerabilities and what adaptation measures are being taken. Explore the overview for a general context of how climate change is affecting Tonga.

Impacts Agriculture

Tonga’s vulnerability to climate change is further exacerbated by the fact that its economy is based largely on agriculture, which in 2008–2009 accounted for 49.9 percent of total gross domestic product, and over 58% of economically active Tongans are reliant on primary production for their livelihoods. Tonga’s primary agricultural crops and livestock include coconuts, pumpkins, squash and gourds, yams, vanilla, and indigenous cattle and pig meat. Traditionally, all the household requirements from agriculture were provided by very complex, robust, and productive multi-storied rotational fallow farming systems. Historically, they prove to be very sustainable, but with increasing population and land pressures for urban development, the fallow periods have shortened and fertility has declined, further highlighting future vulnerability to agriculture production under increased drought periods and more El-Niño like weather. The current and anticipated occurrence of extreme weather events in Tonga causes irreparable damage to food crops and other livelihood materials on which the island population depend. The projected impacts of climate change for agriculture in Tonga include extended periods of drought and loss of soil fertility, which seriously affects agriculture and food security, and tropical cyclones bringing flooding and winds that would damage crops. Much of the prime agricultural land is located on  coastal plains that are threatened by sea level rise.  Further climate-induced changes in temperature, rainfall patterns, sea level, and the intensity of extreme weather events such as cyclones are projected to possibly:

  • Affect the type of crops that can be grown and reduce agricultural yields due to greater heat stress, more frequent and intense drought conditions or water logging, increased flooding of river catchments, and more soil erosion;
  • Favor the establishment and spread of new pests and disease vectors, further threatening the production of crops and livestock;
  • Increase saltwater intrusion in atolls, further limiting what can be grown in these environments and exacerbating existing threats to food security.

This section provides a summary of key natural hazards and their associated socioeconomic impacts in a given country. It allows for a quick assessment of most vulnerable areas through the spatial comparison of natural hazard data with development data, thereby identifying exposed livelihoods and natural systems.


Data presented under Historical Climate Conditions are reanalysis products derived from ERA5-Land data. ERA5-Land is a global land-surface dataset at 9 km resolution, consistent with atmospheric data from the ERA5 reanalysis from 1950 onward. Climate reanalyses combine past observations with models to generate consistent time series of multiple climate variables. They provide a comprehensive description of the observed climate as it has evolved during recent decades, on 3D grids at sub-daily intervals. 

This data has been collected, aggregated and processed by the Climate Resilience Cluster of the European Space Agency’s (ESA) Earth Observation for Sustainable Development (EO4SD) initiative.

% change of crop yield projections
< -60% > 80%
« Click on the map to view site-specific crop data.