Prior to the industrial revolution, increased levels of atmospheric carbon dioxide were attributed to changes in both the sun's intensity and Earth's orbit around the sun, as well as volcanic eruptions. During the last 2,000 years Earth's climate has been relatively stable. Scientists have identified three changes from this stability: the Medieval Warm Period, 900 - 1300 AD; the Little Ice Age, 1500 - 1850 AD; and most recently, post-industrial revolution.
The most recent increases are blamed on
Responses
A a wobble in Earth's orbit.a wobble in Earth's orbit.
B emissions from unexplained volcanic activity.emissions from unexplained volcanic activity.
C increased emissions of CO2 from human activities.increased emissions of CO 2 from human activities.
D increased annual oceanic water temperature that drives CO,2 into the air.increased annual oceanic water temperature that drives CO, 2 into the air.
E the overpopulation of Earth by humans.