6. The variation between glacial and interglacial (warm) climate in the last 800,000 years may be best explained by
Alternating periods of high and low global volcanic activity
Cyclical changes in Earth's position with reference to the Sun
Periodic releases of frozen methane from the deep ocean
Cyclical changes in Earth's albedo
7. Climate scientists use computer models to predict climate in the future. The reliability of climate models is primarily determined by
Running the same model with different grid sizes
Running model components (submodels) independently
Separating natural from anthropogenic inputs in the model
Running the model with known past starting conditions and comparing its output with observations
8. According to the 4th Assessment Report of the IPCC, global temperature is predicted to rise by how about many degrees centigrade in the 21st century?
1 to 4
1 to 8
0 to 2
3 to 7
9. By the last decade of the 21st century, surface temperatures will increase the most in which region, according to the IPCC?
Northern Africa and Saudi Arabia
Equatorial Pacific Ocean
10. The IPCC projects future climate through the use of different scenarios which differ primarily in what way?
The rate of future population growth in each
The pattern of future urbanization in each
The net radiative forcing in each
The particular climate model used for each