CHINA:A report issued today by a leading environmental think tank paints a grim picture for the Earth's burgeoning coastal cities, saying they are in serious danger from flooding, tropical storms and other calamities because of climate change.
Almost two-thirds of the world's cities with a population of more than five million, most of them in developing countries, are in danger from rising sea levels because they fall within coastal areas less than 10 metres above sea level, a zone called the low elevation coastal zone, according to a report by the International Institute for the Environment and Development (IIED).
This area covers 2 per cent of the world's land area, but contains 10 per cent of the world's population and 13 per cent of the world's urban population. Low-income groups living on flood plains are especially vulnerable, the report says.
"Reducing the risk of disasters related to climate change in coastal settlements will require a combination of mitigation, migration and settlement modification," the London-based IIED said.
Climate change will have a much greater impact on developing countries than richer countries, largely because urbanisation in poor countries is driving the poor towards coastal cities.
This is a particular problem in China, where millions of rural poor from the heartland have moved to the rich cities on the eastern seaboard. It also presents major challenges for river delta regions such as Bangladesh.
The European Union wants to cut greenhouse gas emissions blamed for global warming by 20 per cent, compared with 1990 levels, by 2020, boosting that goal to a 30 per cent cut if other industrialised nations join in. It has also urged emerging nations such as China and India to do their bit.
Carbon dioxide, methane and nitrous oxide are the main greenhouse gases, which scientists say heat the Earth, raising sea levels and melting glaciers.
In China and Bangladesh, the urban population in threatened areas is growing at almost twice the national population growth rate between 1990 and 2000.
Although it has fewer large cities than Asia, Europe or the Americas, Africa is also a potential flashpoint because urban growth in the medium-to-large cities is much higher than in other continents.
As of now, most environmental disasters take place in low-lying coastal areas and rising temperatures mean more such hotspots are likely.
"The concentration of populations and economic activities on and near the coast has had serious environmental consequences. Urban systems have radically altered the flows of water, energy and materials, transforming the pre-existing ecosystems," the report said.
Climate change is already a problem in Asia. Between 1994 and 2004, about one-third of the world's 1,562 flood disasters, half of the 120,000 people killed, and 98 per cent of the two million people affected by flood disasters were in Asia, where large numbers of people live in the flood plains of major rivers such as the Ganges, the Mekong and the Yangtze, and the cyclone-prone areas around the Bay of Bengal, the South China Sea, Japan and the Philippines.
One way to reduce the risk to these regions would be to discourage people and firms from moving to at-risk coastal areas.
"Current population movements are in the opposite direction. Given the character of urban development, and that the factors driving coastward movement are still poorly understood, turning these flows around is likely to be slow, costly or both," it said.
Governments need to do more to adapt to climate change in these areas, by being more prepared to deal with disasters and to address local environmental health issues, such as improved water supply, better sanitation, waste disposal and drainage systems.
"Particularly for the urban poor, an equitable resolution of the land issues that drive people to settle on land already susceptible to flooding could make a large difference," the report said.
It recommended international help for vulnerable cities to adapt to climate change, given the international nature of the problem.
"Climate change is closely associated with the past and present lifestyles of high-income groups in high-income countries. This makes it doubly important that the governments of these countries contribute to adaptation as well as mitigation," the IIED said.