Man-Made Climatic Changes: Man's activities have altered the climate of urbanized areas and may affect global climate in the future

摘要: Natural climatic fluctuations, even those of recent years, cover a considerable range. They can be characterized as "noise" spectrum which masks possible global effects man-caused increases atmospheric CO2 and particulates. Local modifications, either deliberate or inadvertent, measurably affect the microclimate. Some artificial alterations microlimate are beneficial in agriculture. Among unplanned effects, produced by urbanization on local temperature wind field quite pronounced. The influences rainfall still somewhat controversial, but may extend considerably beyond confines metropolitan areas. result water vapor released human activity influence condensation freezing nuclei overabundance motor vehicles other combustion processes. Therefore it appears that scale man-made climate substantial natural forces prevail. Obviously this should not lead to complacency. potential for anthropogenic changes larger is real. At stage activation an adequate worldwide monitoring system permit early assessment these urgent. This statement applies particularly surveillance composition radiation balance at sites remote from concentrations population, now entirely inadequate. In my opinion, aerosols, because their optical properties cloud precipitation processes, constitute more acute problem than CO2. Many promptly reversible; hence, one strive elimination source. Over longer intervals, energy added atmosphere heat rejection absorption remain matters concern.