Man (farmers, forest managers) by dealing with water and vegetation changes substantially the distribution of solar energy. Differences in sensible heat (warming) and latent heat (cooling by evapotranspiration) on drained and wetland areas, and the air conditioning effect of a single tree are demonstrated. It is shown that the energy produced in all power stations of the Czech Republic is several orders of magnitude lower than the sensible heat released from the drained and urban areas of the country. A single tree transpiring about 400 1 of water a day has an air-conditioning efficiency of about 20 kW. Whereas photosynthesis (biomass production) uses less than 1% of incoming solar energy, by evapotranspiration (latent heat) more than 50% can be used in water saturated vegetation. Distribution of temperatures (heat potentials) in large areas is shown on satellite pictures. Land managers influence local climate and their important role should be considered in policy-making decisions.