Data taken over time reveal an increase in CO2 in the atmosphere. The large increase in the combustion of hydrocarbons since the Industrial Revolution is often cited as a reason for the increasing levels of CO2. However, an increase in water vapor has not been observed during the same period. Remembering the general equation for the combustion of a hydrocarbon, does the difference in these two trends disprove any connection between human activities and global warming? Explain your reasoning.