Abstract: | The effect of human activity on climate is examined against the background of a rapid increase in the production of man-made heat, which is likely to reach a magnitude of the order of the natural radiation balance on the earth's surface. The microclimate of cities is particularly affected by the production of industrial heat and by the heating of buildings in winter. Deforestation of large areas in conjunction with the expansion of agriculture has an impact on climate. The impact of shelterbelts is analyzed in detail, together with the effect of irrigation, swamp drainage and the creation of large reservoirs. |