How biodiversity can help mitigate climate disasters

It is the deterioration of land and coastlines that amplifies the impact of bad weather weather report. Based on this observation, an idea germinated ten years ago within the United Nations (UN): by preserving, and restoring, ecosystems natural, we can greatly limit the damage of natural disasters. Officially defined by theInternational Union for the Conservation of Nature (IUCN), “Nature-Based Solutions” are “ actions aimed at protecting, sustainably managing and restoring natural or modified ecosystems to directly address societal challenges in an efficient and adaptive manner, while ensuring human well-being and producing benefits for the biodiversity “. Within this framework, three types of actions are carried out: the preservation of ecosystems, the improvement of their management, and the restoration of areas degraded by human activities. Concretely, the flora, the wildlife, the soil of forests and coastlines, but also deserts, meadows or peat bogs. These actions are adaptable anywhere in the world, including in urban areas.

Wetlands: natural sponges

According to the UN, 90% of disasters in the world are related to water. The wet area, like ponds, with their plants and their particular soil, act like sponges and absorb excess water, thus avoiding floods in case of heavy rains. In France, the IUCN recently worked on the banks of the Loire by restoring certain ponds near the river and by planting more plants on the banks to limit the speed of the current. In addition, the water stored in the restored wetlands feeds the water tables and this reduces the risk of drought. This same type of action was also carried out in Essonne (L’Orge) and in Franche-Comté (Drugeon river). The revegetation of ponds and watercourses has also made it possible to accommodate more animal species, but also to restore the capacity for self-purification.

The mangroves, like those of Sri Lanka, are known for their effect during storms, floods or tsunami. Their vegetation makes it possible to reduce the power of waves which surge on the coast and thus slow down the rising water levels. Those sea ​​marshes are filled with multiple, tightly packed, and deeply rooted vegetation that helps soften the impact of the waves, as shown in the UN video, below.

The roots: stabilize the soil and drain excess water

The trees, with their deep roots, stabilize the soil and prevent landslides. In some countries, the UN helps people build ecological and safe roads with certain plants whose roots stabilize roads which tend to collapse in heavy rains. Conifers (pines) in the mountains are great soil stabilizers, but some plants also play the same role, thanks to their very deep roots, such as juniper and vetiver.

Apart from trees, the role of natural meadows is often overlooked. These areas, strongly threatened by urbanization in France, nevertheless have powers against natural disasters. An action underway aims to protect and develop the natural meadows of the Oise valley, to limit the risk of flooding, because the water is absorbed by the roots. In these flood-prone areas, quality hay is now produced, with healthier water, filtered by plants.

Peatlands: essential in the fight against climate change

Peatland areas represent only 3% of the world and yet play a fundamental role in climate regulation. They have the capacity to sequester more than carbon than any other natural space. the carbon dioxide is a greenhouse gas which contributes to global warming. But when they are degraded, turned over and overexploited, peatlands then become immense sources of carbon, releasing into theatmosphere everything they have stored. This is the reason why Indonesia, the country with the largest area of ​​peatlands in the world, recently launched a program to protect these areas.

Fauna: a precious ally

The local fauna also plays a significant role. While some know the role of corals, these natural barriers which attenuate the devastating effect of tsunamis, few know the importance of certain marine animals. Parrotfish tend to crush corals with their powerful jaw-shaped jaws. beak : they then reject them in the form of sand, up to 90 kilos per year! This sand then forms, in turn, a barrier near the coast, mitigating the impact of the waves. It is of course not possible to prevent a tsunami to occur, but the consequences can be limited by preserving the biodiversity coastal edges.

In the great American spaces of the Rockies, it has been proven that plant biodiversity is greatest in areas frequented by bison, or by free-range cattle which benefit from regular rotations of pasture: by plowing the soil, and by rejecting certain seeds in their droppings (which germinate only after being digested), bison and cows make the vegetation richer, and this is how the whole food chain plant-animal which benefits from it, allowing at the same time to sequester more carbon dioxide in the soil thanks to the plants.

Nature-Based Solutions also saves money in the long run: the city of Portland (Maine) in the United States has made the decision to use a forest to filter the city’s water, instead. to build a system ofsanitation waters. By avoiding building an expensive infrastructure that requires maintenance, the city would have saved 155 million dollars in 20 years! The co-benefits of these natural solutions are also numerous, such as the development of tourism interested in the discovery of wild areas and the well-being generated by a pleasant and less polluted living environment.

The idea behind the concept of Nature-Based Solutions is ultimately that humans should work with nature, rather than working against it.