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Global Warming and Technological changes
Recent studies have identified four major global environmental risks: acid rain, ozone depletion, deforestation and the greenhouse effect. On the whole, thanks to technological changes, people now tend to move toward warmer regions in North America and Europe. Climate warming will probably be a boon to Alaska, which is America''s least productive state in Gross National Product(GNP)per square mile.
Studies of the impact of global warming on the United States and other developed regions find that the most vulnerable areas are those dependent on unmanaged ecosystems—on naturally occurring rainfall, run-off and temperatures, and the extremes of these variables. Agriculture, forestry and coastal activities fall into this category.
Most economic activity in industrialized countries, however, depends very little on the climate. Intensive-care units of hospitals, communications, heavy manufacturing and microelectronics are among the sectors likely to be unaffected by climatic change. In selecting whether to set up in, say, Hong Kong or in Warsaw, few businesses will consider temperature a weighty factor.
Greenhouse warming would have little effect on Americas national output. About 3% of American GNP originates in climate sensitive sectors such as farming and forestry. Another 10% comes from sectors only modestly sensitive-energy, water systems, property and construction. For the largest share, 87% , comes from sectors, including most services, that are negligibly affected by climate change.