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从18世纪末期以来,由于森林过伐和大量使用矿物燃料的结果,大气中二氧化碳的含量在不断增多。预计到本世纪末,地球大气中二氧化碳的含量将达到0.038％至0.040％。到2025年将增至0.053％至0.070％。大气组成的变化使地球上气候趋向温暖。据大气和海洋物理学家预测,到2000年,地球上的平均气温将提高0.9至1.3℃,至2025年又将提高1.8至2.5℃。这就是人们常说的“温室效应”。“温室效应”使极地冰雪融化,永久冻土带消失,海平面提高,热带地区降水量明显减少,北半球降水量大大增加……。所有这些变化将使人类赖以生存的地球面临严重的生态危机。“温室效应”对林木有什么影响呢?
Since the late eighteenth century, as a result of over-exploitation of forests and the extensive use of fossil fuels, atmospheric levels of carbon dioxide have been steadily increasing. It is estimated that by the end of this century, the earth’s atmosphere will have a carbon dioxide content of 0.038% to 0.040%. This will increase to 0.053% to 0.070% by 2025. Changes in the composition of the atmosphere make the Earth’s climate tends to warm. Atmospheric and marine physicists predict that by the year 2000, the average temperature on Earth will increase by 0.9 to 1.3 degrees Celsius and in turn will rise by 1.8 to 2.5 degrees Celsius by 2025. This is what people often refer to as the “greenhouse effect.” The “greenhouse effect” melts the polar ice and snow, the permafrost disappears, the sea level rises, the precipitation in the tropics is obviously reduced, and the precipitation in the northern hemisphere is greatly increased ....... All of these changes will put the planet on which mankind lives in a serious ecological crisis. What does “greenhouse effect” have on forest trees?