text: Q:
  
  Sensors for Greenhouse Study
  
  A group and I have the opportunity to design a payload that will be sent up some 100,000 ft (~ 30 km) into the atmosphere for approximately 3 hours. In our design, we were going to include gas sensors so that we can measure gas intensity levels as we go up in altitude. Here are four gas sensors we were thinking of getting:
  
  CH4
  O3
  CO
  CO2
  
  What other gases would you consider useful for studying about pollutants and the greenhouse effect? Are there any above that wouldn't be very useful?
  
  A:
  
  I would add a humidity sensor, as water vapor is the strongest green house gas .
  
  This graph may suggest other gases 
  
  >
  Breakdown of the anthropic greenhouse gas emissions by gas. Source : IPCC, 2007 
  Here is an article on halocarbons.
  
  