Month: August 2026

The Science-Management Days, held on 23 and 24 June, marked the closing week of the CLIPSSA project. Hosted at the Presidency of French Polynesia in Papeete, the event brought together public authorities, researchers and representatives of civil society to explore how the findings of this research-action project can help anticipate the risks posed by climate change.

©Fabrice Charleux

CLIPSSA: Understanding the Climate to Anticipate the Future

“The significance of this achievement is immense because, in the Pacific, science is not merely an added value or an optional source of expertise.” Moetai Brotherson, President of French Polynesia

 ©Fabrice Charleux

Thanks to the invitation and co-organisation of the Government of French Polynesia, IRD, Météo-France and the French Development Agency (AFD) welcomed the CLIPSSA project focal points from across the four participating territories. Participants included representatives from the Directorate of Agriculture of French Polynesia; the Department of Agriculture, Forestry and Fisheries and the Department of the Environment of Wallis and Futuna; the Vanuatu Meteorology and Geo-Hazards Department (VMGD); as well as representatives from the Government of New Caledonia, North Province, South Province, Technopole Nouvelle-Calédonie and the Bio eKo Consultants consultancy. Together, they took part in the closing week of the CLIPSSA project.

Diverse Discussions on Climate Change Adaptation

“CLIPSSA was built upon a strong conviction: responding to climate challenges requires bringing together disciplines and different forms of knowledge.” Mélanie Roué, IRD Representative in French Polynesia

Held on 23 and 24 June, the Science-Management Days created a direct link between scientific knowledge and public action at the Presidency of French Polynesia. Opened in the presence of President Moetai Brotherson and members of his government, the event enabled the CLIPSSA scientific team to work alongside government departments and public services from the territories under study in identifying possible adaptation pathways for the near future, drawing on the project’s scientific findings. This work took place through a series of creative workshops designed and facilitated in close collaboration with the teams from the Directorate of Technology and Innovation (DTI) of the Government of French Polynesia. These Science-Management Days were built directly upon the intermediate conference held in Nouméa in March 2025, which established a genuine space for dialogue between researchers, public authorities and territorial stakeholders. The objective of both events has been to foster the uptake of CLIPSSA’s scientific findings while supporting the co-development of adaptation strategies capable of responding to the expectations and needs of local communities.

Moetai Brotherson and Mélanie Roué ©Fabrice Charleux

A total of 107 participants attended the two-day event, including the scientific teams and the DTI facilitators. Participants represented government departments, project partners—including Météo-France and AFD—local authorities, non-governmental organisations, the agricultural sector and the four territories involved in the CLIPSSA project. One of the main challenges of the event was to address the distinct expectations of the different stakeholder groups. Researchers, public authorities and civil society did not seek the same types of information nor pursue the same objectives.

To respond to these different needs, the workshops were designed around three complementary questions:

• How can the usefulness and potential applications of scientific data be identified?
  For researchers
• How can scientific evidence be integrated into public policies and adaptation plans? For public authorities and decision-makers
• How can future climate conditions, together with the strengths and vulnerabilities of the territories, be better understood in order to prepare for future challenges?
  For civil society

©Maya Leclercq

Understanding and Taking Ownership of the Results

“Having access to these climate data is invaluable for guiding our experimental work and for better characterising how our crop varieties will respond to climate change.”

Sébastien Blanc, Head of the Tropical Root Crops Centre, Technopole Nouvelle-Calédonie

The first, entitled “Understanding, Questioning and Taking Ownership”, focused on presenting CLIPSSA’s main scientific findings. The second, “Co-designing and Integrating”, held on Wednesday morning, aimed to support participants in collectively reflecting on how these scientific findings could be incorporated  into territorial adaptation planning. 

©Fleur Vallet 

During the afternoon, participants took part in a series of mini-conferences organised around five key themes:

• Temperature projections
• Tropical cyclones
• Precipitation
• Agricultural impacts
• Local knowledge

Working in small groups, participants rotated between the different scientific teams. Each session combined a concise presentation of the research findings, a discussion with the researcher leading the session, and a collective reflection structured around the “Three Us”:

• Utility – How useful are these findings?
• Usability – Can they realistically be used by stakeholders?
• Use – How can they be translated into concrete action?

This format enabled every participant to attend each thematic presentation while encouraging direct dialogue with the researchers. The summaries produced at the end of each workshop now constitute valuable working material for identifying which scientific findings are considered most relevant by the various stakeholders, as well as the conditions required for their effective mobilisation in public decision-making.

Integrating Knowledge and Taking Action

“How can these scientific findings be incorporated into public adaptation policies?” Fleur Vallet, Geographer and CLIPSSA Project Coordinator, IRD

 ©Fabrice Charleux

On Wednesday morning, the programme continued with a workshop sequence dedicated to integration. Building upon the scientific findings presented the previous day, participants were invited to identify the information they considered most relevant, assess its potential implications for their territories, compare these findings with the climate plans available to them, and finally develop a series of possible adaptation measures.

The morning concluded with a gallery walk, during which participants visited each group’s work to discuss the proposed ideas, followed by a Samoan Circle. This facilitation method created an open and inclusive space for participants to share their experiences, encouraging both active listening and collective dialogue. The objective was not to produce immediate operational solutions. Rather, the workshops were designed to initiate a collective learning process, enabling participants to experiment with a working method grounded in the integration of scientific evidence into territorial planning and climate adaptation processes.

On Wednesday afternoon, the momentum generated during the Science-Management Days continued with a workshop dedicated to strengthening the adaptation component of the French Polynesia Climate Plan (PCPF). The workshop was organised by the consultancy K Ora as part of its project management support to the Department of the Environment (DIREN).

Building directly upon the work carried out within CLIPSSA, the workshop aimed to take the process one step further. Whereas the previous sessions had enabled participants to understand and take ownership of the climate data and to identify priority climate impacts, this workshop focused on comparing these findings with existing public policies in French Polynesia. Participants assessed whether the adaptation measures already included in the Climate Plan were sufficient and explored opportunities to strengthen them by drawing inspiration from adaptation initiatives implemented in comparable island contexts.

The workshop brought together representatives from several government departments around an island archetype approach, distinguishing between high islands with barrier reefs, the Tuamotu atolls and urban centres. This approach encouraged participants to move beyond sector-specific perspectives and begin designing adaptation strategies from an integrated, cross-sectoral perspective.

Planning for the Future Rather Than Enduring It

“We all come from island states and face common challenges arising from the impacts of climate change and extreme weather events on our ways of life.” 

Antfalo Levu Boaz, Director of the Vanuatu Meteorology and Geo-Hazards Department (VMGD)

Participants’ feedback highlighted a strong appreciation for the workshop format. The mini-conferences encouraged direct exchanges between researchers and participants, while the presence of facilitators fostered active participation from audiences with diverse backgrounds and areas of expertise.

The presentations dedicated to Climate Science, Social Sciences and Humanities (SSH) and Agricultural Impact Modelling generated particularly rich discussions, reflecting the strong interest shown in these three complementary components of the CLIPSSA project.

The workshops held on Wednesday morning further confirmed this positive dynamic. The scientific resources made available throughout the event were widely used by participants, and the working groups rapidly embraced the proposed methodology, establishing numerous connections between CLIPSSA’s scientific findings and the strategic priorities already identified within their respective territorial climate plans.

These two days demonstrated that sustained dialogue between researchers, public authorities and civil society can lead to concrete outcomes that are both scientifically robust and closely aligned with the needs of local communities.

If this collaborative dynamic continues through the long-term uptake of CLIPSSA’s scientific findings by public authorities, the project has the potential to support the development of adaptation strategies capable of guiding public action to safeguard Oceanian ways of life in the decades ahead.

For those wishing to relive the event, a highlights video is available on the CLIPSSA website and on the IRD YouTube channel. The full programme of the Science-Management Days, together with the presentations delivered on Tuesday 23 June, is also available here.

                                              

The photographic exhibition created from Jean-Michel Boré’s documentary The Marriage of Knowledge was presented at Te Fare Iamanaha – Museum of Tahiti and the Islands from 16 to 20 June, and at the University of French Polynesia from 22 to 25 June 2026. Through a series of photographs, the exhibition highlighted both the transformation of South Pacific ecosystems and the local knowledge developed by communities in response to the increasing hazards associated with climate change.

©Willis Waweru – Te Fare Iamanaha – Museum of Tahiti and the Islands

Images That Tell the Story of the Territories

©Willis Waweru – Te Fare Iamanaha – Museum of Tahiti and the Islands

As part of its closing activities, the CLIPSSA research-action project set out to create a photographic exhibition illustrating, through the power of images, both the value of its research and the importance of preserving the territories at the heart of the project.

Twelve photographs depicting New Caledonia, Vanuatu, Wallis and Futuna, and French Polynesia were selected from the documentary work of IRD filmmaker Jean-Michel Boré. While producing The Marriage of Knowledge, Boré captured striking landscapes, personal testimonies and traditional techniques. Together, these images not only gave rise to a compelling documentary—available on the IRD YouTube channel—but also formed a powerful visual collection presented to the public during the CLIPSSA project’s closing week.

Bringing the Exhibition Closer to Its Audience

     ©Willis Waweru – Université de la Polynésie française

The CLIPSSA photographic exhibition was conceived as a parallel event to the project’s closing conference, with the aim of raising awareness among the populations of the territories under study about the impacts of climate change.

To reach a broad audience, it was displayed at Te Fare Iamanaha – Museum of Tahiti and the Islands from 16 to 20 June, before moving to the Research Auditorium of the University of French Polynesia from 22 to 25 June.

Through this strong territorial presence, CLIPSSA reaffirmed its commitment to serving the communities living in the territories that form the focus of its research. The exhibition also reflects the project’s commitment to scientific accountability by returning the results of research to the citizens concerned.

Traditional Pacific Crops Facing the Threat of Climate Change

On June 2, 2026, the South Province of New Caledonia, in partnership with CRESICA, hosted a public conference as part of the C’Nature series dedicated to the impacts of climate change on island agriculture. On this occasion, two postdoctoral researchers in climate science from the CLIPSSA project, affiliated with the IRD (French National Research Institute for SustainableDevelopment), Gildas Guidigan and Dakéga Ragatoa, presented the major findings of the agronomic component of their work. Together, they provided answers to a question that seems simple on the surface, yet is central to food security in Pacific territories: what is the future oftropical root crops—taro, yam, and cassava—in the face of inevitably rising temperatures inWallis and Futuna, French Polynesia, Vanuatu, and New Caledonia between now and the end of the century?

Why Focus on Tropical Root Crops?

Yam, taro, and cassava are not merely subsistence crops. The researchers, in consultation with the governments and provinces concerned, recalled their symbolic and social significance: asymbol of tradition and identity, a legacy passed down by ancestors, a food for sharing and solidarity, and a marker of resilience and pride for Oceanian societies. Global warming and itsdirect consequences on subsistence farming thus pose a concrete question: how can we prepare for it, and through what means? Specific varieties were selected for this study, such as Veo, Taloulu, Vegi ulu liliki or Vegi kau’i ti, Fiji taro, Kari, Florido, Taiwata, Maniota Ufi, and Manioka(Manihot esculenta).

 

Dakéga Ragatoa ©Willis Waweru

A Cascading Methodology: From Regional Climate to the Crop Field

To answer this question, the team set up a multi-step modelling chain. Projections from the IPCC global climate model (resolution of approximately 100 to 200 km) were refined through regionalization using the ALADIN (~20 km) and AROME (~2.5 km) models developed under the CLIPSSA project, as well as additional debiased regional models from the SOCLE-OM project (NIWA from New Zealand, AUS-CORDEX from Australia).
These climate data then feed into the APSIM Next Gen (APSIM-X) agronomic model, which simulates daily plant growth. The studied varieties were created using the APSIM-Potato module. Data availability varies across territories: New Caledonia possesses relatively comprehensive climate, soil, and agronomic data, whereas for Vanuatu, French Polynesia, and Wallis and Futuna, only climate data were directly used, with other parameters extracted or estimated from
scientific literature and existing technical sheets.

Scientific Modelling in the Service of Food Security

To anticipate potential yield declines, the scientific team cross-references climate models with the APSIM plant growth simulation model to spatialize (after calibration and validation) projections at a very fine scale (2.5 km grid cells). This tool integrates soil characteristics, atmospheric parameters (temperature, rainfall, solar radiation), and agronomic data collected in the field, allowing researchers to simulate plant development from planting through to potential
yield (biomass and water use).

 

Gildas Guidigan ©Willis Waweru

 

Warning for Studied Taro Varieties, Resilience for Yam Varieties: Contrasting Diagnoses

The results presented outline a worrying trajectory for taro, which is particularly sensitive to heat stress, while yam emerges as a pillar of resilience (in comparison to taro):

● Wallis and Futuna: Heat stress already at play: In Wallis and Futuna, under the SSP3- 7.0 scenario (equivalent to a +4°C increase in mainland France by 2100), local warming is estimated at +1.37°C by 2050 and +3.04°C by 2100 for the Alo and Hihifo sites. Simulations show a continuous decline in the average potential yield of all three crops—especially taro (talo ulu)—along with a sharp increase in poor harvest years by the end of the century. Heat stress emerges as the most decisive climate factor. Comparing the three crops, taro, cassava (manioka), and yam (vegi) all show slight declines in potential yield over time (taro losing the most), while cassava remains more stable—a finding that, according to researchers, calls for a rethinking of root crop
planning in the territory.

● French Polynesia: In French Polynesia, simulations focused on three specific crops: taro (Veo variety, Colocasia esculenta), yam (Dioscorea alata), and cassava (Maniota Ufi variety, Manihot esculenta). Spatialized outputs project a drop in potential yields compared to current observations. The sensitivity analysis conducted with APSIM-X confirms this downward trend for both crops and, as in other territories, identifies heatstress as the primary climate factor driving this decline (researchers note that at this stage, only climate parameters are considered, excluding non-climatic socio-economic or agronomic factors). Taro will suffer an alarming drop of around 29% in its potential yield as early as 2050. Bad harvest years could increase by up to 60% by 2070. High-
production areas in Tahiti and Moorea will shrink, and cassava could cross the critical threshold of 50% losses in the rainiest sectors.

● Vanuatu: Fiji water taro will reach its thermal limits by the end of the century: Vanuatu faces the most concerning diagnosis of the presentation: Fiji taro, which is already experiencing significant heat stress, could lose up to 60% of its potential yield by 2100, with a marked acceleration in losses after 2050—up to 46% of the years classified as loss years over the studied period. Conversely, yam varieties (Dioscorea alata and Dioscorea esculenta) appear significantly more resilient, with losses limited to 5–19% depending on the models and varieties; Dioscorea esculenta is considered particularly reliable for future food security. Temperature, precipitation, and solar radiation all influence yields, with temperature remaining the dominant factor for taro. Researchers emphasize the need to prioritize the promotion of adapted yam varieties, farmer training, varietal diversification, adjusting planting dates, mulching, organic manure application,agroforestry, and establishing early warning systems, with special attention given to the northern islands of Vanuatu, identified as priority zones for adaptation investments.

● New Caledonia: In New Caledonia, the picture is more nuanced. Taro (CTT75 Kari), already close to its optimal temperature, is expected to see its yields gradually decrease (between -21% and -32% by the end of the century), with a sharp increase in poor harvestyears after 2080 and a possible shift of cultivation areas to cooler regions; low-altitude coastal areas, particularly on the East Coast and in the North, could become unviableafter 2060. Yam, on the other hand, shows overall higher robustness: the CTT100 Florido variety is projected to remain virtually stable until 2100 (a loss of 2% to 7% dependingon the model) and, according to researchers, represents the primary food security crop to prioritize. Meanwhile, CTT230 Tiawata shows a moderate decline but remains productive and viable throughout the century. Notably, solar radiation and precipitationinfluence yam yields more than temperature, whereas temperature remains the main constraint for taro. Researchers recommend immediately expanding the cultivation ofCTT100, diversifying heat-tolerant taro varieties, adjusting planting calendars before the 2040s, and implementing an early warning system for yield anomalies.

Diversifying and Anticipating: Keys to Agricultural Adaptation

Faced with the projected increase in “bad harvest years”, IRD researchers emphasize the urgent need to adapt farming practices in Oceanian gardens. The future of food sovereignty in theseterritories will depend on strategic choices co-designed with producers:

1. Varietal Adaptation: Promote heat-resistant replacement crops (such as Florido yam) and encourage farmers to mix multiple varieties and species in their fields to identify those best suited to climate variations.

2. Technical Adjustments: Advance planting dates (with shifting seasons) by 3 to 6 weeks to avoid heat peaks, implement widespread mulching to retain soil moisture, and optimize organic manure application.

3. Agroforestry: A practice that already exists locally but provides substantial microclimate
benefits.

Gildas Guidigan ©Willis Waweru

Shared Messages Across the Pacific

Beyond the specificities of each territory, several common takeaways emerge: across all studied sites, heat stress is the single most penalizing climate factor for root crop yields, particularly for taro. However, water availability must not be overlooked, as water sources are also drying up
with global warming. Yam consistently stands out as the most resilient crop (in this study) to climate change, making it a primary adaptation strategy (alongside other heat-resistant species and varieties) to bolster food security across Pacific territories, while cassava and especially taro appear more vulnerable depending on the zone. Finally, researchers stress that resilience does not mean an absence of risk: even the most stablevarieties require proactive adaptation practices (varietal selection, crop calendars, soil and water management) before losses accelerate—particularly around the 2050–2060 horizon, which several models identify as a tipping point.

Translating Research into Public Policy

This conference served as a vital reminder of the absolute necessity to translate scientific research into concrete public policies. Facing climate disruption occurring literally “under our feet”, combining data-derived technical solutions with the daily experience of farming communities will be the indispensable engine driving Pacific resilience. The event concluded with a Q&A session with the audience and expressions of gratitude delivered in several Pacific languages (Māuruuru, Tankiu tumas, Malo, Oleti)—reflecting the resolutely regional dimension of the CLIPSSA project. CLIPSSA brings together climate scientists, anthropologists, agronomists, and local communities around a single shared challenge:preparing the Pacific’s subsistence agriculture today for the climate changes of tomorrow.