Global Warming-More than Hot Air?

摘要

We know from weather station records that Earth's surface temperature has increased on average by 1.0 °C in the last 150 years. The last ten years have been the warmest decade on record. Over the same period, global sea level has increased by 10 to 20 cm. We know also that planet Earth has an atmosphere that creates a natural greenhouse effect, keeping our surface warmer than it would be otherwise. Human activities are substantially increasing the atmospheric concentrations of greenhouse gases, principally carbon dioxide and methane, to levels far above those that have existed for the past 200,000 years. We do not know, on the other hand, all the details of our complex climate system sufficiently well to predict the exact consequence of greenhouse gas increases on global temperature. Should we wait for greater certainty about global wanning or should we take steps immediately to stabilize possible climate change? Global trends suggest that allowing "business as usual" is a risky path. World population is now 6.5 billion and will likely rise to 10 billion in the lifetimes of our children. Much of the population growth will be in developing countries with a natural desire for an increased standard of living. That living standard increase, according to current examples, comes with increases in per capita energy consumption. Because 90% of society's energy presently is produced by burning fossil fuels, the inevitable population increase and drive towards higher standard of living simultaneously aggravates the enhanced greenhouse gas condition and with it, global warming. There is an alternate path. We could unleash our engineering, economic, and political entrepreneurs to improve energy conservation and efficiency and move us towards greater use of renewable energy sources. Technology and training in energy efficiency and use of non-polluting fuels could allow developing nations to skip the carbon intensive, energy-production stage of industrialization. Such a path would simultaneously reduce excessive consumption in developed countries and provide conditions that would bring worldwide population growth under control. Global wanning may be the "smoke alarm" that pushes us to action.