Earth has a fever, but the heat is sloshing into the oceans
Much has been made about the Earth's energy imbalance (extra energy absorbed by the Earth). It is clear the Earth is out of balance, what isn't clear is how bad it is. A new study by Dr. Matt Palmer and Dr. Doug McNeall moves us closer to answering this question.
These scientists used data from the latest group of climate computer models (CMIP5) to look at the relationships between the energy flows at the top of the atmosphere, the surface temperature of the Earth, and changes in ocean energy. They made (in my mind), three important conclusions.
First, there is a lot of variability in the Earth surface temperature. In fact, these natural fluctuations of the Earth surface temperature (0.3 degrees C per decade) can mask much of the underlying global warming. Consequently, you cannot use Earth surface temperatures over 10 years or so as an indicator of the Earth "fever".
As we look over longer periods of time, the "masking" of global warming by internal fluctuations gets smaller; however, even for 15 years or so, natural fluctuations and human-caused global warming can be about the same size.
Second, the authors found that an increase in the ocean energy explains almost all (95%) of the variation in the Earth energy balance. This means that more complete measurements of the global oceans would enable us to better measure the "fever." Finally, for time periods longer than a year, the ocean becomes the dominant storage reservoir for heat.