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.

Adaptation Options for Key Sectors

  • Introduce heat and drought tolerant crops: The current sources of vegetables for Tongans are mostly European cool vegetables like cabbages, tomatoes, potatoes, etc. With the expected temperature increases as part of the climate change phenomenon, there is a need to introduce heat and drought tolerant vegetable crops both for domestic consumption and export potentials.
  • Improve pest and disease management: The predicted climate change phenomenon will create a new pest and disease regime, and therefore the need to develop improved pest and disease management program.
  • Restore degraded lands: Sea level rise will result in land degradation implies that there should also be a degraded land restoration policy to restore lands for purposes including agriculture.
  • Diversity agriculture: Vulnerability studies should be carried out and agricultural diversification plans drafted for vulnerable areas. These should include potential non-agricultural developments better fitted to the predicted conditions of the vulnerable area.
  • Use climate-change-ready crops: Climate adaptable crop varieties are being established at the Centre for Pacific Crops and Trees (CePaCT) to ensure that Pacific Island Countries and Territories (PICTs) have access to planting material with climate ready traits, such as drought and salt tolerance. The Government of Tonga should develop a strong relationship with the Centre to ensure transfer of knowledge and technology to Tongan Farmers.
  • Install permanent monitoring systems to obtain vertical salinity profiles in the freshwater lenses on Tongatapu, Lifuka in the Ha'apai Group and Vava'u and monitored at regular intervals.
  • Implement a national hydrological network: There is no functioning information or data exchange systems on water resources assessment and monitoring. Water resources are currently managed by a number of institutions, and there is a need for a collaborative approach to management including integrated planning, the introduction of buffer zones, demand management strategies, and comprehensive education to demonstrate the links between poor sanitation and waterborne disease and environmental degradation.
  • Establish water governance programs: At present there is insufficient political and public awareness of the critical role of water in Tonga, and due to little formal communication and coordination among government departments national water governance is fragmented and weak. An overarching water governance department should be established to monitor and manage water resources and to implement adaptation and groundwater protection measures specific to this sector.
  • Develop and implement alternative water supply methods: Expansion of rainwater collection schemes can offer ‘drought proofing’ during future droughts.
  • Land use planning and water reserves: Effective land use planning and management would garner protection of water resources from contamination, which is especially important to the coral islands of Tonga as they have highly permeable soils and shallow water tables.
  • Establish water reserves or ‘groundwater protection zones’ and regulate land use where potential freshwater resources exist for future use. This will require negotiation between government and private landowners and agreement on appropriate administrative, legal and financial conditions.
  • Develop Integrated Coastal and Marine Zone Management Plans: Several management strategies for minimizing the adverse effects of climate change on marine resources have been proposed, which include measures such as conservation, restoration, and enhancement of habitats such as mangroves and coral reefs as well as some species such as giant clam and trochus.
  • Coral Reef Vulnerability Studies: In recognizing the potential for such a resource for the country, it is imperative that research and monitor be carried out to determine vulnerability and critical areas of coral, as well as research conducted to examine the different types of coral communities, their health and link it to climate change, variability, extreme events and sea level rise impacts and facilitating adaptation measures.
  • Implement bilateral and multilateral agreements and protocols regarding the exploitation and management of shared stocks such tuna. Aquaculture also may be considered as another means of reducing stress on wild stocks.
  • Coastal re-vegetation: One of the on-going counter-measures against coastal erosion is re-vegetation, which involves planting various coastal plant species along coastlines with important infrastructures such as roads and house. This measure is especially effective within affected zones.
  • Expand the use of computer modeling on marine fishery vulnerability: Currently, there are no computer models developed yet specifically for the assessment of climate and sea level change impacts on marine fisheries resources such as tuna, however a regional approach in using of computer models for assessment of climate change impacts have been developed but it is in early stages of development.

Gaps and Needs

  • Studies need to be carried out to address the “island dilemma” and downscale climate models to individual islands, however it may not be possible to derive more accurate climate change information due to the small size of these islands. New information should be credible and useful to decision making at the island scale.
  • Addressing sea level and storm surge risks will require the use and interpretation of the information that is coming out of the South Pacific Sea Level and Climate Monitoring Project and incorporating it into sector-specific early warning and monitoring systems and overall applied research assistance is required to properly establish an island-specific and robust baseline from which to gauge projected changes and impacts.
  • Standardized health impact assessment procedures, tools and methods are being developed in Tonga however further research is needed including developing innovative approaches to analysis weather and climate in relation to human health, and improving understanding of how to incorporate outputs from Global Climate Models (GCMs) into human studies.
  • Expanded use and distribution of SimClIM is imperative, which is a simplified software package that generates climate change scenarios and sea level rise at the sub-regional level developed by The University of South Pacific and the International Global Change Institute (Ne Zealand).
  • Expanded access and training is needed in utilizing and understanding the TongaSimClim software, which has been customized for use by Tonga with a local, very high resolution (30 meter), digital elevation model for the islands of Tongatapu, Vava'u, Ha'apai and Niuatoputapu.
  • Because of scaling problems, these sea surface temperature projections for the most part apply to open ocean surfaces and not to land surfaces, and thus the temperature changes may well be higher than current projections.
  • GCMs for the Pacific Island Countries and thus Tonga are not yet able to provide reliable and true indication of how rainfall patterns might change in the Three of the five GCMs (ECHAM4, CSIRO2-EQGFDL- TR) used to model rainfall using the preliminary SRES scenarios suggest an increase in rainfall in the next 100 years while the other models (HADCM2, CGM1-TR) suggest the opposite.
  • There appears to be a gap in efforts with respect to those focused on reducing vulnerability within the health and fisheries sectors—two priority areas of identified by Tonga.
  • Gender is not a prominent focal area of any current adaptation projects or proposed strategies.
  • Tonga also identified the need to develop a national climate change framework and policy. The extent to which progress has been made towards achievement of this goal remains to be determined; as too is the extent to which adaptation is being mainstreamed into sectoral planning other than forestry.
  • Institutionalize and mainstream climate change preparedness.
  • Increase public awareness and improve understanding of climate change, variability, sea level rise, extreme events and their preparedness.
  • In order to monitor and indentify the patterns and impacts of various climatic variables in relation to changes in the abundance, growth, reproduction, mortality, distribution, diversity and behavior of marine species and habitats and in particular tuna fisheries, training of appropriate personnel in population biology and stock assessment is required and improved access is needed to accurate monitoring instruments and equipment.
  • Improvements are required to the country’s meteorological services, including restoring and upgrading the basic infrastructure and operations, putting in place an appropriate local capacity-building program to improve scientific/technical staff resource levels and to upgrade skills, and building climate change Issues into national development plans.
  • Available evidence shows a deterioration of the information system and analytical tools in most Pacific island countries over the past 10-15 years. Establishing a robust observation network is a critical first step towards addressing potential natural hazard risks and overall applied research assistance is required to properly establish an island-specific and robust baseline from which to gauge projected changes and impacts.
  • Modeling of storm-surge zones is needed and must take into consideration possible sea-level rise to develop planning mechanisms that can be used to direct current and future investments in infrastructure, housing construction, and agriculture outside this zone to minimize vulnerability, reduce repair costs and decrease disruption to economic activities.
  • Although future projections of mean air temperature are rather consistent among climate models, projections for changes in tropical cyclones and wind direction and strength remain uncertain. Regional Climate Models (RCMs) and statistical downscaling techniques may prove to be useful tools to address this gap.
  • To be effective, risk management of natural hazards, including vulnerability and hazard mapping, needs to be incorporated into the national processes that are crucial to decision making: the national development plans, budgets, sectoral plans, policies and regulations. Further, end-to-end Early Warning Systems for all hazards need to be improved.
  • The use of existing meteorological information is limited to specific agencies, and this information needs to be tailored to decision makers across a wider series of sectors.
  • Building and development codes continue to suffer from weak enforcement and lack of consequences for non-compliance and the Tonga building code it not yet legally mandatory.