Luxurious resorts, pristine beaches and lush forests define the popular image of tropical islands. But behind this idyllic facade, a quiet land crisis is unfolding, compounding the threat posed by rising sea levels.
Land degradation – a phenomenon most associated with dry regions of Africa and Central Asia – is also occurring in tropical island nations. When land degrades, soil loses its productivity, biodiversity and overall health, which can lead to food shortages and forced migration.
Small Island Developing States (Sids) is a UN-recognised group comprising 39 states and 18 associate members. Sids are “among the most vulnerable countries to land degradation due to their physical nature, small size and escarped landscapes,” according to a 2020 UN report. The issue is also reaching critical levels among larger island nations, such as Indonesia.
Island nations “have to balance the provision of food and all the other services that come from nature”, Barron Orr, chief scientist of the UN Convention to Combat Desertification (UNCCD), tells Dialogue Earth. “Ensuring that there is integrity of the land and the soil is key.”
Drivers of the crisis
At the recent UNCCD COP16 in Riyadh, Saudi Arabia, the convention’s executive secretary, Ibrahim Thiaw, warned that “every second, somewhere in the world, we lose an equivalent of four football fields to land degradation.” For island nations with limited landmass, the impact can be more pronounced.
Eric Browne, the UNCCD’s focal point in Saint Kitts and Nevis, tells Dialogue Earth: “If we have a drought, it’s the whole island that is affected. If we have a flood, we can’t run away.”
In the Philippines, nearly half the country’s land – 14.26 million hectares – was degraded in 2019, according to the UNCCD. Halfway across the globe in the Dominican Republic, more than one third of the land – 1.49 million hectares – was similarly affected that year.
“Islands are usually pictured as paradise,” says Estrella Penunia, secretary general of the Asian Farmers’ Association for Sustainable Rural Development. But Penunia, who is based in Manila, says in her country “decades of neglect over agriculture, and the exploitation of natural resources, are now threatening our lands and soils.” Human activities such as unsustainable logging and mining cause the problem.
Climate change further compounds the issue, disrupting once-reliable alternations between dry and wet seasons.
“The distribution and the amount of rainfall have changed,” says Chay Asdak, a professor of the management of watersheds at Universitas Padjadjaran in Indonesia. In some areas rainfall has increased, while in others it has diminished.
The misuse of synthetic fertilisers also plays a role, says Orr. “The good news of fertilisers is you give immediate food to your plants and they grow. The bad news is, by short-circuiting all of that natural biology, you lose many other factors that are important for healthy soils.”
Synthetic fertilisers also reduce the land’s ability to absorb flood waters, because the organic matter that is necessary for soil to hold water is lost. “If it happens to an island developing state, that can be very serious,” he continues. “It can really impact how well that system responds to drought and to flooding.”
Threats of desertification
Desertification is land degradation in dry areas. Surprisingly, it is a threat to tropical islands that have mountainous terrain, due to a scientific concept called the “orographic effect”.
The phenomenon occurs when wind blowing from the sea to an island is forced to rise over a mountain. As the wind climbs the slope, it cools and forms clouds, leading to rainfall on the sea-facing side of the mountain. But the opposite side gets little rain as the wind descends and warms up.
“You end up with a very dry environment on the other side of these mountains,” Orr explains. “If we have degradation in those dry areas, now we are facing the risk of desertification.”
In the mountainous parts of Indonesia, orographic rainfall can also trigger landslides on slopes and flooding in low-lying areas.
According to Asdak, deteriorating soil and rising urbanisation is making it harder for rainwater to seep through the ground in wet seasons, which increases the chances of seasonal drought.
In Trinidad and Tobago, the situation is similar. Poor farming practices and quarrying are the leading causes of land degradation there. As climate change brings more intense and shorter periods of rain in the wet season, land degradation leads to faster water flows, which overwhelm the island’s small river systems and make the soil more vulnerable.
The dry season, on the other hand, is also becoming longer and more intense. According to David Persaud, an environmental manager at the Ministry of Planning and Development of Trinidad and Tobago, this is straining water supplies and forcing reliance on seawater desalination. His country experienced “the worst drought in recent memory” this year, forcing the government to ration water for months.
“Increasing demand and competition for land uses as the population grows, such as for housing, agriculture and other development areas, compounds these challenges,” Persaud tells Dialogue Earth.
Actions needed
Addressing these challenges requires “financing and capacity building,” says Browne of Saint Kitts and Nevis. He works as a forestry officer in the country’s Ministry of Environment, Climate Action and Constituency Empowerment.
Browne says providing people with the knowledge to look after their soil and deal with land degradation and drought is vital. “How is my soil doing? What crops are most suited for us in dealing with drought? We need research on these,” he says.
If we don’t plant thirsty crops, we have more water available. And if we put the biology back in our soil, so we have organic matter, we increase more crop per dropBarron Orr, chief scientist of the UN Convention to Combat Desertification
Better land-management practices can make “a big difference” for small island nations, Orr explains. “If we don’t plant thirsty crops, we have more water available. And if we put the biology back in our soil, so we have organic matter, we increase more crop per drop.”
Another priority is to improve the global dataset for monitoring and assessing land degradation in small island nations. This is something these countries have underscored repeatedly. The lack of data also makes it hard for the global audience to “quantify and visualise” the intensity of land degradation and drought in these countries, says Praveena Sridhar, chief technical officer of the Save Soil movement.
Over the past few years, the UNCCD has supported Small Island Developing States by helping them to access high-resolution imagery and data. This can better prepare them for the future.
The effort is part of a programme to help them achieve “land degradation neutrality” by 2030 – a target of the UN’s Sustainable Development Goals. But for many islanders, including Browne, more help is needed because the situation on the ground is getting “very serious”.
The good news is, action is being taken. During COP16 in Riyadh, nearly 200 countries reached an agreement. They requested the UNCCD and the Global Mechanism – which facilitates the mobilisation of financial resources – to work with their partners to ensure the accuracy and consistency of high-resolution land data. This applies especially to Sids and other developing countries confronting this growing crisis.
