Earth Flashcards
The Changing Climate
The climate change is a natural phenomenon and normally occurs over several centuries. The term refers to current changes in the climate. This is because recent records show global climate is warming up rapidly.
The Early Atmosphere
As there were no humans on early earth to measure early atmospheres, scientists must use indirect methods to determine such. One theory suggests there was intense volcanic activity.
The Volcano Theory
Present-day volcanoes release large amounts of gases, it’s believed early volcanoes did too. Nitrogen built up and water vapour condensed to form oceans and little or no oxygen was present then.
Algae & Plants
Algae first produced oxygen and as plants evolved, the percentage of carbon dioxide decreased and with it, oxygen levels increased. This allowed the evolution of organisms that needed oxygen to survive.
