Answer:
Demographic Transition Possible Stage 5: Decline A possible stage 5 of the demographic transition is predicted by demographers for some developed countries. Stage 5 would be characterized by very low CBR, an increasing CDR, and therefore a negative NIR.
CO2 is an important trace gas in Earth's atmosphere. It is an integral part of the carbon cycle, a biogeochemical cycle in which carbon is exchanged between the Earth's oceans, soil, rocks and the biosphere. Plants and other photoautotrophs use solar energy to produce carbohydrate from atmospheric carbon dioxide and water by photosynthesis. Almost all other organisms depend on carbohydrate derived from photosynthesis as their primary source of energy and carbon compounds.
The overall specific gravity of the earth is much higher than the specific gravity of crustal rocks which means the earth is about twice as heavy as the rocks on the surface would suggest. Iron meteorites are thought to have the same composition as the average earth, and the meteorites contain a lot more iron than the Earth's surface rocks.