That is because the climate would greatly affect the environmental system, which could affect our livelihood, even to the extent of our existence.
For example, in the change of temperature and aridity, which we often heard about, can affect our food supply, living area and biodiversity. Allow me to elaborate.
For food supply, plants and crops grows at different temperatures and aridity, such as wheat are able to cold and dry area while rice is able to grow only in humid and warm areas. If the temperature rises, we may soon find the growing of certain crops difficult because the species cannot adapt to the rise or fall of temperature.
For living area, the continued rising of temperature lead to the melting of icecaps, increasing the sea level, and may soon flood some of the coastal areas, leading to the reduce of living area.
Similar to plants, animals can survive in certain temperature only, and when the temperature and aridity change, they may increase or decrease due to the changes in food resources hence affecting the food chain.
Given these changes, scientists have to predict future climate in order to find resolve for these changes so as to balance the ecosystem artificially and prepare for future change.
Hope it helps!
