3. Deforestation: Trees and plants prevent sunlight from falling directly on lakes, ponds or rivers. When deforestation takes place, these water bodies are directly exposed to sunlight, thus absorbing more heat and raising its temperature. Deforestation is also a main cause of the higher concentrations of greenhouse gases i.e. global warming in the atmosphere. - See more at: http://www.conserve-energy-future.com/causes-and-effects-of-thermal-pollution.php#sthash.hDHbsKlv.dpuf