The economic and financial impact of global warming is complex and not well understood. In some scenarios there would be economic benefits for countries that get warmer and wetter and consequently more fertile agriculturally. Drier weather in some regions would result in sharply lower crop yields.
Overall, changes in climate are expected to cause significant disruptions that also exact an economic toll. Advisers to the Intergovernmental Panel on Climate Change say that the world economy may suffer losses of between 0.2 per cent and 2 per cent of income if temperatures rise by two degrees Celsius from recent levels.
Below are some of the costliest impacts, according to a 49-page summary from the Intergovernmental Panel on Climate Change which met in Yokohama near Tokyo this week.
- Energy: Demand for residential air conditioning in the summer will rise from 300 terawatt hours a year in 2000 to about 4,000 terawatt hours in 2050 and more than 10,000 terawatt hours in 2100. Rising incomes will drive most of that increase, climate change a quarter of it. For comparison, Vietnam currently consumes about 100 terawatt hours of power in a year.
- Infrastructure:Relocation of industries and communities will cost billions of dollars even in wealthy countries. Countries must also reckon with damage to transport infrastructure, homes, industries and agriculture from increasingly extreme weather, droughts and storms, especially in low-lying coastal areas.
- Water: The impact is unpredictable: wetter weather could yield a windfall of $3 trillion in the U.S. in the 21st century; drier weather could raise costs by $13 trillion. Ensuring enough water for industry and other consumption will cost about $12 billion a year worldwide while development of water supply and provisioning in developing countries will cost $73 billion.
- Food productivity: A need for more labour to produce food to offset dropping crop yields could leave fewer workers available for other work. As food becomes more expensive, consumers may shift to cheaper foods but also spend less on other goods and services. Climate change may also increase competition for labour, capital, land and water.
- Poverty: Scientists say climate change will worsen poverty, especially in tropical, developing countries, but even in affluent countries. Climate-related diseases such as malaria and diarrhea impair children's cognitive and physical development, while higher child death rates may lead parents to have more children, reducing the amount of money available to care for and educate each child.
- Conflict: Climate change raises the risks of violent conflict such as civil wars by amplifying the impacts of poverty and economic crises, while increasing competition for scarce land, water and food. The resulting damage, deaths and instability would exact a steep toll on affected economies.
- Intangibles: Apart from the monetary toll from damage and uncertainties connected with climate change many impacts will exact a price impossible to tally in dollars and cents, said Rajendra Kumar Pachauri, a co-chairman of the climate change panel. "We mustn't forget there are a lot of impacts that you cannot quantify easily," he said, such as human deaths, extinction of species, damage to ecosystems, loss of cultural heritage, among many.