A Lecture on Greenhouse Gases
Angel C. de Dios
"The Earth system follows laws which scientists strive to understand,"
said Dr. F. Sherwood Rowland, a Nobel laureate in chemistry.
"The public deserves rational decisionmaking based on the best scientific advice about what is likely to happen, not what political entities might wish to happen."
From: Preeminent Scientists Protest Bush Administration's Misuse of Science
When I first added "Greenhouse Gases" as a topic in my General Chemistry, I shared with another Filipino American scientist the slides I prepared for that first lecture. This was back in 2008 and the following was his response.
Josefino "Joey" Comiso is a scientist at NASA. His contribution to the study of climate change is his observation of the decline in Arctic sea ice during the past decades.
- troposhere; This is the layer directly above us and it stretches up to 10 kilometers in altitude.
- stratosphere: This is right above the trophosphere and here we will find the ozone layer. This is the part of the atmosphere where there is an equilibrium between O3(ozone) and O2(oxygen) molecules. The ozone layer protects us from harmful ultraviolet rays from the sun.
- mesosphere: This lies above the stratosphere, stretching 50 to 85 kilometers from the earth's surface. This is where the temperature decreases with height.
- thermosphere: This lies highest. This is where molecules are ionized by the sun's radiation. Due to these ionizations, the temperature increases as one goes up through this layer.
The rise and fall of CO2 in a year corresponds to the changes in season, which correlates to the times of the year when trees have leaves and are therefore performing photosynthesis. During the spring and summer, there is a drop in CO2 since photosynthesis uses CO2. Nonetheless, the overall trend, year over year since the 60's is continuous rise in CO2 levels in the earth's atmosphere.