<Tr> <Th> Region </Th> <Th> Industrial CO </Th> <Th> Total CO </Th> </Tr> <Tr> <Td> OECD North America </Td> <Td> 33.2 </Td> <Td> 29.7 </Td> </Tr> <Tr> <Td> OECD Europe </Td> <Td> 26.1 </Td> <Td> 16.6 </Td> </Tr> <Tr> <Td> Former USSR </Td> <Td> 14.1 </Td> <Td> 12.5 </Td> </Tr>

Define and give 4 examples of greenhouse gases