Why would it be difficult to limit the impact of thawing permafrost on global warming?

Which number shows the location of the united kingdom of great britain? 7 5 2 4

What major factors play a role in global warming? 1. human activity and normal climate conditions 2. natural factors and human activity 3. normal climate conditions and abnormal human activities 4. abnormal human activities and natural factors

Where is the only location in the united states where you drive on the left side of the road?