<Table> Carbon dioxide in Earth's troposphere <Tr> <Td_colspan="2"> 2011 carbon dioxide mole fraction in the troposphere </Td> </Tr> <Tr> <Td_colspan="2"> <Ul> <Li> </Li> <Li> </Li> <Li> </Li> </Ul> </Td> </Tr> </Table> <Tr> <Td_colspan="2"> 2011 carbon dioxide mole fraction in the troposphere </Td> </Tr> <Tr> <Td_colspan="2"> <Ul> <Li> </Li> <Li> </Li> <Li> </Li> </Ul> </Td> </Tr> <Ul> <Li> </Li> <Li> </Li> <Li> </Li> </Ul>

How much carbon dioxide was present in earth's atmosphere 4 billion years ago