Answer to Question 1
TRUE
Answer to Question 2
Answers should include the following gases:
Water vapor (H2O): most abundant, but low residence time. Natural sources.
Carbon dioxide (CO2): greatest contributor; long residence time; anthropogenic sources and natural sources. Currently 400 ppm.
Methane (CH4): high global warming capacity; intermediate residence time; high global warming potential; largest sources are anthropogenic; 750 ppb.
Nitrous oxides (N2O): higher than any time in the last 100,000 years. long residence time; high global warming potential; emissions associated with agriculture contribute to rise, but also some natural sources.
Halogens (CFCs, etc.): 100 anthropogenic; high global warming potential, but greatly reduced due to Montreal Protocol.