The number of people worldwide vulnerable to a devastating flood is expected to grow to 2 billion by 2050 due to climate change, deforestation, rising sea levels and population growth in flood-prone lands, warn scientists at the United Nations University (UNU).
One billion people – the majority of them among the world’s poorest inhabitants – are estimated to live today in the potential path of a 100-year flood and, unless preventative efforts are stepped up worldwide, that number could double or more in two generations.
The greatest potential flood hazard is in Asia. Every year for the past two decades, more than 400 million people on average have been directly exposed to a flood. Between 1987 and 1997, 44% of all flood disasters worldwide affected Asia, claiming 228,000 lives. Economic losses in the region in that decade totaled US $136 billion.
The fast-growing cost to the world economy of floods and other weather-related disasters (now $50 to $60 billion per year, much of it in developing countries) is roughly equal to the global development aid provided by all donor countries combined.
- more extreme weather systems that accompany global climate change,
- rising sea levels; and
- continuing deforestation, especially in mountain regions.
It also predicts that pressure to live and work in flood-prone areas, which typically feature attractive rich soils, abundant water supplies and ease of transport, will increase as the world’s population continues spiraling upward – to a projected 10 billion by 2050.
“The growing frequency and magnitude of extreme environmental events worldwide has intensified research interest in natural disasters as well as regional vulnerability and response capabilities,” says Dr. Janos Bogardi of UNU.
“In the warmer, wetter world predicted by science today, the northern part of the Northern Hemisphere will likely see more storms while some continental areas might have drier summers and more risk of drought. Sea levels could rise, fed in part by melt-water from glaciers and ice caps. Along with this, extreme high-water levels may occur with increasing frequency. Higher sea levels could inundate small islands, flood coastal lowlands, and erode sand dunes. It is also necessary to ensure that increasingly freakish climate variability and the gradual forces of climatic change and deforestation are factored into the total picture,” he said.
Mortality is often highest in rural areas of poor countries where disaster preparedness and early warning is virtually non-existent and where health coverage is usually weak or not easily accessible. In such areas, people are less likely to evacuate from flood prone areas – and in some cases fear leaving and potentially losing their possessions or their property claim.
“The thousands of tragic casualties from flooding and Haiti and the Dominican Republic in recent weeks underline the extreme vulnerability of developing countries,” Dr. Bogardi said. “While economic losses due to natural disasters destroy resources equivalent to 2% of GDP in developed countries, in developing countries, the proportion can reach as high as 13% of GDP. Unsustainable practices and the ever increasing disasters they trigger prevent people to break through the brutal cycle of poverty.”
Scientists say warming sea temperatures may increase the number of cyclones and storm surges reaching shore. Storm surges can be just as lethal as the weather systems that spawn them – “walls of water” 60 to 80 kilometres across and 2 to 5 metres high that can pour in from the sea with immense force, washing away everything in their path. The most massive storm surge in recent times caused 300,000 deaths in the coastal wetlands of Bangladesh in 1970.
“In view of the ever increasing flood disasters and other threats to human security, there is an urgent need to reassess how we respond and prevent the potential of catastrophic loss of life and economic damage from natural disasters,” says Under Secretary-General Hans van Ginkel, Rector of UNU.
Addressing the problem from the perspective of human security requires a paradigm shift in thinking towards disaster prevention and preparedness, says Dr. Bogardi.
“Instead of starting with the focus on natural hazards and their quantification, the assessment and ranking of the vulnerability of affected groups should serve as the starting point in defining priorities and remedial interventions.”