Over the next century, scientists expect sea-level rise to be one of humanity’s greatest challenges, with ecosystems, communities and infrastructure all under threat.
Image: Dr Simon Albert at UQ with a research drone.
Researchers from the UQ School of Civil Engineering are studying the reasons behind the rising waters in the South Pacific paradise, while monitoring the speed at which waters are rising, and finding ways to understand the impact on the people living in these remote areas of the world.
Recently, five reef islands in the Solomon Islands were lost completely due to sea-level rise and a further six islands have seen severe coastal erosion. These lost islands range in size from one to five hectares, and they supported dense tropical vegetation that was at least 300 years old.
Nuatambu Island, previously home to 35 families, has lost over half its inhabitable area, with 75 per cent of houses destroyed by the sea since 2011.
The research team, led by Dr Simon Albert, has combined traditional knowledge of the local inhabitants with cutting-edge technology such as drones to help guide locally-appropriate adaptive responses to this critical issue.
The team monitored the coastlines of 33 reef islands across the Solomon Islands using aerial and satellite imagery from 1947–2016.
The team compared historical photos dating from World War II with modern-day satellite images to track the islands’ growth and retreat over time. This information was integrated with local traditional knowledge, radiocarbon dating of trees, drone-derived topography, sea-level records, and wave models.
This is the first scientific evidence that confirms the numerous anecdotal accounts from across the Pacific of the dramatic impacts of sea-level rise on coastlines and people.
For the past 20 years, the Solomon Islands has been a hot-spot for sea-level rise and is now considered an insight into the future of similar communities.
Here, the sea has risen at three times the global average, around 7–10 millimetres per year. This higher local rate is due to natural climate variability, but these dramatic rates are in line with what we can expect across much of the Pacific due to human-induced sea-level rise.
The rapid changes to shorelines observed in the Solomon Islands have led to the relocation of several coastal communities that inhabited these areas for generations. These were not planned relocations led by governments or supported by international climate funds; rather, they were ad-hoc relocations using the communities’ own limited resources.
In some cases, entire communities have left their coastal villages that were established in the early 1900s by missionaries, and retraced their ancestral movements to resettle old inland village sites used by their forefathers.
“Before this place was our paradise – the centre of our community – but now the sea has taken that from us we must move up the hill. While we are now safe from the sea we are faced by challenges of water supply, sanitation and landslides," Rence William, community elder of Nuatambu, said.
Linking this rich knowledge and inherent resilience in the people with technical assessments and climate funding is critical in guiding global adaptation efforts, and guarding the future of the world’s vulnerable island communities.