An island at risk
Réunion combines the characteristics of its insularity, tropical climate, volcanism and relief. These features have shaped remarkable ecosystems: high mountains, primary dry and humid forests, coral massifs. However, this biogeographical situation exposes the region to a number of major natural hazards: cyclones, floods, landslides, forest fires, earthquakes, swells, storm surges and tsunamis. These geographical and climatic constraints are compounded by anthropic pressures. The island's population is growing fast and density is high. This growth could reach one million inhabitants by 2030, mostly concentrated on the coast, which contributes to accentuating the pressure on a constrained and fragile natural environment.
Risks associated with sugar cane monoculture
Sugar cane accounts for 56% of the island's agricultural land. The plantations are adapted to withstand the climatic conditions of the "windward" coast and are seen as helping to curb erosion. Production residues, or bagasse, are used as biomass to generate steam and electricity in bagasse/charcoal power plants. Sugar cane cultivation is, however, associated with the use of some fifteen phytosanitary products (herbicides, rodenticides, etc.), some of which have been withdrawn from the European market but still benefit from derogations by the Ministry of Agriculture. Official measurements have revealed pollution of surface and ground water by pesticides, including substances used in sugar cane cultivation, some of which exceed threshold values. A study published by Santé publique France in 2019 (as part of the MatPhyto DOM project) shows that in 2014 "50% of pesticides used on sugarcane were potentially carcinogenic, reprotoxic or endocrine-disrupting". In addition to the worrying issue of pesticide contamination of the environment, the subsidized cultivation of sugar cane weakens the region, which depends on exports of this monoculture, developed at the expense of food crops. In particular, the island imports large quantities of rice, the staple food in the Indian Ocean. However, experiments to set up an organic rice industry are currently underway on the island.
Growing energy consumption and heavy dependence on fossil fuels
Réunion is heavily dependent on imported fossil fuels (oil, coal). As a non-interconnected zone (with France's electricity transmission network), its energy dependency rate was 85.8% in 2022. Energy consumption is also on the rise, in an area where public transport is underdeveloped and alternatives to the car are still very marginal. A tram-train project was abandoned in 2010 following a political change at the head of the regional council. The funds earmarked for the project were ultimately invested in the construction of... an expressway, the new Route du Littoral. The isolation of the region also makes it inevitable to use airplanes to travel off the island. Transporting goods on the island (by road) or abroad (by air or sea) also consumes a great deal of energy and carbon. Population growth and the development of tourism (almost 500,000 tourists by 2022) tend to increase the region's energy requirements and carbon footprint. As a result, travelers are advised to be frugal in their consumption of resources.
Guidelines for achieving carbon neutrality
Under the Paris agreements, the island is committed to achieving carbon neutrality by 2030. This commitment requires strong action aimed at both reducing energy consumption and producing local energy with low greenhouse gas emissions. The levers of action put forward are the control of energy consumption (reduction of consumption, energy efficiency of buildings, raising public awareness), the development of low-carbon mobility (tramway, regional bicycle plan) and the production of renewable energies. The region has hydroelectric power stations. It is also focusing on the valorization of biomass (bagasse or the development of fibre cane cultivation, methanization of compost). The region is also considering the development of solar and wind farms (with the problem of the unpredictable yield of this type of energy). Geothermal energy projects have been developed in the past, but have not yet been finalized.
Waste management efforts
Waste management is a key environmental issue on Reunion Island. The figures speak for themselves: Reunion Islanders generate around 694 kg of waste per capita per year (compared with 450 kg in mainland France, where a great deal still needs to be done). Only 30% of waste is recycled, and landfill is currently the main outlet for waste. Existing facilities will be saturated by 2023, and unauthorized landfill sites are not an epiphenomenon. On the other hand, regulations impose restrictions on the ultimate storage of waste (French law on energy transition). Alternatives to landfill are met with reluctance (notably the construction of an incinerator), and few concrete, large-scale initiatives are underway. The region has, however, embarked on an ambitious waste prevention policy since 2018, namely a circular economy ("zero waste") approach. An action plan aims to achieve a 27% reduction in household and similar waste by 2030, notably through source reduction initiatives, the structuring of reuse and recycling channels (repair workshops, bio-waste recovery), as well as awareness-raising initiatives (the fight against food waste, for example). Civil society initiatives are also emerging, such as the Terra Océana association, which organizes litter picks on beaches and raises public awareness of plastic pollution. A documentary to be broadcast in 2019, L'Éveil péi, highlights the local initiatives undertaken on the island to protect the environment.
Protection of natural environments
The main threats to ecosystems are man-made. Since colonization in the 17th century, hunting and later urbanization have led to the disappearance of species and natural habitats. Deforestation and the introduction of invasive species (guava, maroon vine) are also weakening endemic species, some of which are threatened with extinction (white sweet wood).
Reunion National Park. Created in 2007, the Parc national de La Réunion protects the island's remarkable terrestrial ecosystems. Its pitons, cirques and remparts have been an integral part of the World Heritage List since 2010, for their "universal and exceptional value". The park is home to unique yet fragile landscapes and biodiversity. It protects endemic and endangered species such as the Barau petrel and the Bourbon green gecko, as well as remarkable ecosystems such as primary dry and humid forests. The integrity of primary forests is vital for maintaining the evolutionary dynamics of living organisms. Today, it still covers 30% of the island's territory. Its decline is linked to deforestation, but also to the introduction of invasive exotic species. "Preserving the forest is everyone's business", as Parc National de La Réunion is keen to point out. In addition to its protection missions, the park is also involved in disseminating knowledge to the general public and raising environmental awareness. The lucky hikers who will be able to walk in these grandiose spaces are therefore urged to stay on the trails to preserve the flora and fauna.
Réserve naturelle marine de La Réunion. This 3,500-hectare marine protected area was created in 2007. It aims to preserve reef biodiversity, which is also threatened by human activities (pollution, overfishing, poaching, wastewater). The reserve's missions are to develop knowledge and surveillance of the coral reef, and to raise awareness of its fragility. Divers and other marine observers are invited to take part in the monitoring network, and tours are organized throughout the year to introduce the curious to the Ermitage lagoon. Today, it is estimated that 15% of the island's coral is threatened. Visitors are invited to find out about safe, healthy alternatives to chemical sunscreens. These filters can be harmful to coral reefs.
Last but not least, marine biodiversity (fish, turtles, mammals) is fragile and under threat. An approach charter has been drawn up to enable you to observe mammals (whales, dolphins, etc.) and turtles with respect for living creatures (www.reunion.fr).
The Kélonia museum in Saint-Leu, a sea turtle observatory, is an excellent introduction to the issues involved in preserving environments and species. You'll also be able to observe these ladies, all dressed in scales.
