In my previous post, I discussed the relationship between the orbit of the Earth around the Sun and fluctuations between periods of climate warming and cooling. In this post I’d like to explain how that works. I already pointed out that the Earth is currently defying all previous behavior by experiencing warming when it should be entering a period of cooling. The data I present at the end of this post will show why.
Climate change is caused by climate forcings. James Hansen, of Columbia and NASA, has provided this definition of a climate forcing: it is “an imposed perturbation (disturbance) of the planet’s energy balance.” So what does this mean?
The concept is actually fairly simple. The Earth is in energy equilibrium, with that equilibrium defined by how much energy the Earth absorbs versus how much it radiates. In other words, the amount of energy the Earth absorbs from the Sun must equal the amount of heat it radiates into space. If one of these values changes, then the other must adjust. For example, if the amount of solar radiation reaching the Earth decreases (as explained in the global cooling scenario in my prior post), the temperature of the Earth must also decrease. This is what causes ice ages. Conversely, if the amount of solar energy that reaches the Earth increases, the Earth’s temperature must rise. read more »