Plants have always been tightly bound to the development of human civilisation. The demise of one can spell doom for the other. Introductory part presents the fate of an ancient city of Uruk which decided to respond the growing problem of overpopulation by cutting the trees, which in turn caused a chain reaction of water pollution and the drying of their complex irrigation system. On the other hand, the city of Anuradhapura faced the same problem, but they did not cut down their trees and that resulted in the city flourishing and remaining populated to this day. The importance of forests is immeasurable, they don't just create oxygen, but their roots serve as a natural water filter, and their canopies provide shade which affects the local climate. Additionally, trees provide a home to a great number of species. The cities of today face many problems in the wake of climate change. Large concrete areas absorb enormous amounts of heat which results in greater temperatures than the surrounding area. In order to face this heat island effect, it is important to increase the green cover areas, and that can be done by utilising green facades and roofs, green balconies, sky gardens, planed tree planting, lawns, urban gardens and orchards. The roles of greenery in combating the effects of climate change are many. They create shade which protects the areas from direct solar radiation, with the effect of evapotranspiration they disperse heat back into the atmosphere which results in lower local temperatures. Greenery provides a great thermal insulation as well as the protection from wind and noise. It provides natural ventilation of buildings which reduces the need for air conditioning systems and energy consumption. The thesis deals with all the mentioned cases of greenery, especially trees, green roofs and façades, because these cases are crucial in combating the ever-increasing temperatures. There are numerous tree benefit calculators that anyone can use to calculate the various benefits that trees provide over a given period of time. Two such calculators are described in the paper, those being “Omni Calculator" and "MyTree Calculator". The first one is a simpler calculator, while the second is more complex. Both calculators were applied to several trees from the area of the City of Rijeka and the Municipality of Viškovo, and their functionalities were compared based on the results. In the methodical chapter of the work, the curriculum of the secondary vocational school for profession is analysed, and it is possible to integrate the topic of this master thesis therein, as well as to apply it through the inter-curricular course of Sustainable Development. Also, the methodological chapter contains preparation for the lesson for which the topic of "Green" architecture is planned.