Question

Most modern forms of transportation are powered by fossil fuels. Carbon dioxide, methane, carbon monoxide, and other gases are released into the atmosphere during the production and combustion of these fuels. How might these gases cause climatic changes? These gases have no effect on atmospheric temperatures, so they are unable to cause any type of climatic changes. These gases cause more water vapor to condense, making climates wetter than they were in the past. These gases reduce the amount of thermal energy escaping into space, effectively warming the atmosphere.

Answer 1

The correct answer is the last option.

The first option (unable to cause climate change) is incorrect because these gases do effect the atmospheric temperatures by increasing them.
The second option is incorrect because while these gases do cause more water vapor to condense, they result in acid rain (not wetter climates). 

Answer 2

Greenhouse gases, such as carbon dioxide, methane, and water vapor, are released into the atmosphere in large quantities during the production and combustion of fossil fuels. These gases help to reduce the amount of thermal energy escaping into space, effectively warming the atmosphere.