[单项选择]Global warming is the gradual increase of the temperature of the earth’s lower atmosphere as a result of the increase in greenhouse gases since the industrial Revolution. The temperature of the atmosphere near the earth’s surface is warmed through a natural process called the greenhouse effect. Visible, shortwave light comes from the sun to the earth, passing unimpeded through a blanket of thermal, or greenhouse, gases composed largely of water vapor, carbon dioxide, methane, nitrous oxide, and ozone. Infrared radiation reflects off the planet’s surface toward space but does not easily pass through the thermal blanket. Some of it is trapped and reflected downward, keeping the planet at an average temperature suitable to life, about 60°F (16℃).
Growth in industry, agriculture, and transportation since the Industrial Revolution has produced additional quantities of the natural greenhouse gases plus chlorofluorocarbons and other gases, augmenting the thermal blanket. It is generall
A. A．4, the author suggests that ______. scientific predictions are accurate and trustworthyB. the effectiveness of the models simulating the climate is not yet provedC. observed climate changes is the representative of changes in global warmingD. mankind is the only one who is to blame on the issue of global warming