The recent calamities in Myanmar and China are stark reminders that—despite advances in the detection and mitigation of natural disasters—many people in the world still live in harm’s way.
The threats posed by tsunamis, earthquakes and other natural disasters are as old as the world, but the world is constantly changing. Despite declining fertility rates, global population continues to rise and it’s rising fastest in some of the more disaster-prone areas of the world.
The cyclone that devastated Myanmar may or may not be related to climate change, but climate change is expected to intensify cyclones and typhoons in South Asia. The fourth assessment report of the UN’s Intergovernmental Panel on Climate Change (IPCC), released late last year, noted that:
Recent studies indicate that the frequency and intensity of tropical cyclones originating in the Pacific have increased over the last few decades (Fan and Li, 2005). In contrast, cyclones originating from the Bay of Bengal and Arabian Sea have been noted to decrease since 1970 but the intensity has increased (Lal, 2001). In both cases, the damage caused by intense cyclones has risen significantly in the affected countries, particularly India, China, Philippines, Japan, Vietnam and Cambodia, Iran and Tibetan Plateau (PAGASA, 2001; ABI,2005; GCOS, 2005a, b).
The IPCC report predicted that:
Countries in temperate and tropical Asia are likely to have increased exposure to extreme events, including forest die back and increased fire risk, typhoons and tropical storms, floods and landslides, and severe vector-borne diseases.
South Asia is not the only part of the world that is affected by rising oceans and increased storm activity. The Organization for Economic Cooperation and Development (OECD) released a study last December that estimated the exposure of 136 of the world’s largest port cities to coastal flooding. The study concluded that the number of people in these 136 cities (each with a population of one million or higher) that are currently exposed to a 1 in 100-year coastal flood event will more than triple by 2070. At present, about 40 million people are at risk. By 2070, the number will rise to about 150 million due to the “combined effects of climate change (sea-level rise and increased storminess), subsidence, population growth and urbanization.”
The OECD report also found that “asset exposure could grow even more dramatically,” reaching $35 trillion by the 2070s, “more than ten times current levels and rising to roughly 9% of projected global GDP.”The report concluded that even if cities adopt high levels of protection in the future, “the large exposure in terms of population and assets is likely to translate into regular city-scale disasters across the global scale.” The report went on to say that, “The policy implications of this report are clear: the benefits of climate change policies – both global mitigation and local adaptation at the city-scale – are potentially great.”
Population change, particularly increasing urbanization, may also be exposing more people to the threat of earthquakes. This year marks the first time in history that half of the world’s population lives in an urban environment. While urbanization entails some potential benefits, it also heightens certain risks. GeoHazards International, a nonprofit research group seeking to reduce suffering due to natural disasters, issued a statement (“Trends in Global Urban Earthquake Risk: A Call to the International Earth Science and Earthquake Engineering Communities”) a few years back, that warned:
Urban earthquake risk in poor countries is large and rapidly growing. Fifty years ago, the population of the world’s largest earthquake-threatened cities was equally divided between rich and poor countries. Today, there are five times as many people in poor as in rich earthquake-threatened cities. Fifty years ago, the earthquake resistance of buildings in rich countries was better than that of buildings in poor countries, and since then it has steadily improved, while that in poor countries has steadily worsened. Data of the U.S. Office of Foreign Disaster Assistance indicate that the average number of deaths resulting from fatal earthquakes in rich countries decreased by about a factor of 10 between the first half of the 20th century and the last half. This improvement in seismic safety is presumably the result of, among other things, better building and land-use codes and better enforcement of those codes. By contrast, there are indications that earthquakes in developing countries will increase their lethality in the future.
The 2004 statement went on to note:
The future does not look better. In the next 20 years, the world’s population will increase by 2 billion. Of that 2 billion, only 50 million will be added to industrialized countries, the rest to developing countries. Because of internal migration, from the countryside to cities, the urban population of developing countries will increase by itself by 2 billion people over this period. Imagine that in the next 20 years the combined population of today’s India and China will be added to such cities as Algiers, Cairo, Istanbul,Ankara, Aleppo, Teheran, Tabriz, Mashed, Kabul, Quetta, Rawalapindi, Delhi, Calcutta, Dhaka,Yangon, Manila, Jakarta, Mexico City, Guatemala City, Bogotá, Quito, and Lima. Recall that the 8th World Conference on Earthquake Engineering occurred only 20 years ago. In that same amount of time, 2 billion people will appear in some of the world’s poorest cities and will need places to live, learn, and work. Given the lack of resources and the urgency to build, the quality of construction will, unless something changes quickly, continue to decline.
As these and other statements suggest, various population trends—including population growth, urbanization, and the growing number of people living in coastal regions—pose a significant challenge to governments and international institutions seeking to mitigate the death toll resulting from large natural disasters. That’s why understanding these demographic trends—their magnitude and their implications—becomes ever more important to policymakers around the world.
