Klimatske spremembe in njihovi vplivi na razvoj organizmov so del naravnega procesa razvoja planeta Zemlje. Usmerjajo njihove prilagoditve in pospešujejo ali zavirajo njihovo razširjenost v prostoru. V določenih primerih so klimatske spremembe tako drastične, da jim določeni organizmi ne morejo slediti; tako podležejo spremenjenim življenskim pogojem in izumrejo. Vzroki za globalne klimatske sprememb in posledično izumiranje so zelo različni. Nastajajo zaradi spremenljivega položaja Zemlje v vesolju, zaradi potovanje kontinentalnih plošč, vulkanske dejavnosti, velik pomen pa imajo tudi padci meteoritov, ki v zelo kratkem času izrazito spremenijo podnebje. V geološki zgodovini poznamo najmanj pet velikih množičnih izumiranj, ki so zajela celoten planet. Le eno izumiranje se je zgodilo zaradi ohlajevanja ozračja, medtem ko so vsa nadaljnja izumrtja sledila povišanjem temperature. V članku so opisani vzroki za vseh pet množičnih izumrtij in njihov vpliv na takratno življenje na Zemlji.

Climate changes and their effects on the organisms’ development are part of the natural process of Earth’s evolution. They direct the adaptations of the organisms and accelerate or reduce their distribution in the area. Climate changes can be in particular cases so drastic that certain organisms can not follow them and for that reason become extinct. The causes for global climate changes and consecutive extinction are various; changable position of Earth in the universe, movement of continental plates, vulcanic activity, meteorite fall, causing big climate changes in short time period. At least fi ve massive extinctions which affected the whole planet are known in the geological history. Only one of them was due to atmosphere cooling while all the others were caused by temperature increase. In the present paper, the causes of all fi ve extinctions and their infl uence on the life on the Earth are described.