
The Raging Debate on Climate Change
Who is a skeptic?
Let us look at the data! What do you think has happened since the Industrial Revolution when most of the combustion of fossil fuels has occurred? Climatologists have been keeping records of the composition of the air around the world for about 60 years now. One of the longest recordings is from the Mauna Loa Observatory in Hawaii.
Why the roller coaster ride? Recall the carbon cycle has both photosynthesis and decay occurring, so in the Spring when plant life is growing, the CO2 concentration falls, while during the Fall and Winter the decay process dominates and the CO2 concentration increases.
Happy with that explanation? Here is the updated data, the trend has continued

If you answered no, give yourself a pat on the back. Remember that it is Winter in Australia when it is Summer here. So how can the CO2 concentration cycle? The Southern hemisphere is mostly water and so the summer/winter activities in the northern hemisphere dominate.
Click for the transcript.
SPRING: (Image of the tilt of the earth in the spring) In this configuration, the earth is not tilted with respect to the sun’s rays (The earth in this picture is actually tilted towards you as indicated by the fact that you can see the North Pole – green dot). Therefore, radiation strikes similar latitudes at the same angle in both hemispheres. The result is that the radiation per unity area is the same in both hemispheres. Since this situation occurs after winter in N. Hemisphere we call it spring, while in the S. Hemisphere it is autumn. This occurs on March 21.
SUMMER: (Image of the tilt of the earth in the summer) When the N. Hemisphere is tilted towards the sun, the sun’s rays strike the earth at a steeper angle compared to a similar latitude in the S. Hemisphere. As a result, the radiation is distributed over an area which is less in the N. Hemisphere than in the S. Hemisphere (as indicated by the red line). This means that there is more radiation per unity area to be absorbed. Thus, there is summer in the N. Hemisphere and winter in the S. Hemisphere. This situation reaches a maximum on June 21.
AUTUMN: (Image of the tilt of the earth in the autumn) In this configuration the earth is not tilted with respect to the sun’s rays (The earth in this picture is actually tilted towards you as indicated by the fact that you can see the North Pole – green dot). Therefore, radiation strikes similar latitudes at the same angle in both hemispheres. The result is that the radiation per unit area is the same in both hemispheres. Since this situation occurs after summer in the N. Hemisphere we call it autumn, while in the S. Hemisphere it is spring. This occurs on September 21.
WINTER: (Image of the tilt of the earth in the winter) When the N. Hemisphere is tilted away from the sun, the sun’s rays strike the earth at a shallower angle compared to a similar latitude in the S. Hemisphere. As a result, the radiation is distributed over an area which is greater in the N. Hemisphere than in the S. Hemisphere (as indicated by the red line). This means that there is less radiation per unit area to be absorbed. Thus, there is winter in the N. Hemisphere and summer in the S. Hemisphere. This situation reaches a maximum on December 21.