On the islands of Ontong Java in the Solomon Islands (pictured), a South Pacific state three hours by air north-east of Brisbane, time isn’t wasted arguing about climate change. In the main village of Luaniua, islanders have for years witnessed irreversible sea level rise.

It has broken down sea walls, flooded villages, inundated food-producing land and contaminated freshwater wells. Houses have collapsed with coastline erosion, tree cover has declined, increasing human and plant vulnerability to the intense tropical sun, and, day by day, people’s energy is consumed more by basic survival.

“There is not enough food and water for everyone, there is not enough to eat,” Hugo Kahano from Luaniua’s House of Chiefs told Crikey. “We now rely on imported food delivered by boat once a month, but this is not enough.”

“We first noticed the impacts of climate change on Ontong Java in the 1990s. Plans to address climate change should have started then. Now is too late.”

Satellite data shows the sea near the Solomon Islands has risen annually by 8mm over the past 20 years, compared to the global annual average of 3mm. Ontong Java in Malaita Province possesses a total land area of 12 square kilometres, is an average two metres above sea level, with a population of about 3000.

Since 2010, the Anglican Church of Melanesia has worked on improving food security for its Polynesian communities. “The main problem is saltwater intrusion into the soil,” George Bogese, ACOM’s mission aid and program officer, explained in the capital Honiara. “Last year we concentrated on implementing atoll permaculture, and this year we will deliver rainwater tanks.”

Atoll permaculture involves the multi-layered cultivation of fruit trees, vegetables and root crops on constrained land. Salt-resistant varieties of the staple crop, swamp taro, an important part of the diet alongside fish and coconuts, have also been trialled. But yields still fall short and, chiefs Richard Poki and Hugo Pakoa say, urgent deliveries of relief supplies are needed now. They acknowledge they will eventually lose the islands that have sustained them for thousands of years.

For the Solomon Islands government, climate change is the most critical development issue facing the nation, and it is now bracing for the impact of climate-induced migration.

Who will make the final decision on migrants’ fate? In a nation where 87% of land is under customary, not state ownership, can enough land be secured for new settlements?  In a least developed country, where will the money and capacity come from to relocate an entire island’s population?

More than 85% of the nation’s 550,000 people practise subsistence livelihoods in rural areas on an archipelago of more than 900 islands. Living on the Pacific Rim of Fire with relentless risk of earthquakes, tsunamis and cyclones, islanders are no strangers to natural disasters. But more climate-associated devastation spells greater poverty and landlessness in a nation ranked 143 out of 187 countries for human development.

Pearson Simi, provincial disaster officer in Auki town, Malaita Island, 400km south of Ontong Java, confirms a relocation strategy is being developed. “We have identified some government land in Central and South Malaita, but we will also have to find customary land to accommodate everyone,” he told Crikey.

“We are already facing land issues with development and it will be a very challenging issue when moving people.”

Poki is adamant solutions require a bottom-up process. “Our people want to make the decision about relocation and where we will resettle,” he emphasised. “The first priority is proper consultations between the government, churches and our communities.”

The voices of those directly affected need to be heard and ways of maintaining livelihoods, cultural and social cohesion agreed upon. Many who voluntarily left Ontong Java in the past seeking work have gravitated to the capital, Honiara, where 35% of residents live in squatter settlements. Further escalation of slum communities is unsustainable.

With governments struggling to cope with 30 million people internally displaced today in countries around the globe, destitution and indignity is an anxiety for those confronting climate-associated loss. By 2050, Pacific nations could be grappling with up to 1.7 million climate migrants, according to a recent London School of Economics report.

The Solomon Islands government aims to have its first climate change relocation policy completed by the end of the year, but there will be formidable challenges in implementation.

“The number one obstacle will be land,” Hudson Kauhiona, climate change deputy director at the Ministry of Environment in Honiara, said. “We are already facing land issues with development, and it will be a very challenging issue when moving people.”

Less than 13% of land in the country is owned by the government, and traditional landowners rarely sell. If they do, acquisition, with most customary land not surveyed or registered, often entails long, complex and difficult negotiations with high demands for remuneration.

“We would not sell our land because it brings benefits to our families and it contains the resources we need, such as water, rivers and forests,” said Alfred Gegeo, a landowner on Malaita Island. “Also we need our land to provide for population growth.”

Land transactions between customary and non-customary landowners have triggered inter-generational grievances, as in the civil conflict known as the Tensions (1998-2003), which was fuelled by youth angered at the selling of their lands by the previous generation. But Kauhiona predicted population issues are likely to impact resettlement arrangements in the future: “There are clear boundaries to the land where people are allowed to come and stay. In one or two decades they may go beyond those boundaries. It is a living process.”

The Pacific Climate Change Science Program forecasts a maximum possible sea level rise of 15 centimetres in the Solomon Islands by 2030. Ontong Java is expected to be the first of many cases in the coming decades where people are forced to abandon their islands and villages.