The use of a global average surface temperature trend as a diagnostic to monitor global warming is, at best a crude approach, and at worst an erroneous tool for that purpose.
This post summarizes why.
First, to describe global warming, let’s use the seminal paper
Ellis et al. 1978: The annual variation in the global heat balance of the Earth. J. Geophys. Res., 83, 1958-1962
While the specific values they reported in their paper can be updated with the newer data since 1978, the framework and general conclusions are equally valid today. Excerpts read [highlight added] – with their figure 4 presented at the top of this post:
It’s so good to read actual science, as opposed to CAGW religious tracts. Always pleased to see something that makes scientific sense.
The earth-ocean-atmosphere is a system not in equilibrium. The measure of heating of this system should be the change in its enthalpy. In an elementary view, the use of temperature ignores, among other things, the heat capacity differences in various parts of the system. Use of temperature as the prime indicator of warming can’t help but be wrong both quantitatively and qualitatively unless the temperatures of all parts of the system are always either decreasing or increasing.
Excellent posting! Pielke Sr. has his act together! We should be seeing a modified sine wave in the seasonal graphic, despite the orbital damping effect resulting from precession of the equinoxes. For the Jan-Feb discontinuities, I suspect NH albedo effects (winter only) may play a role, as there is no similar change in the SH due to diminished land area subject to snowfall, but I need to explore this further, and I’m traveling as this is being written, so that will have to wait.
Your turn Roger! (& JNG too!) Beat me to it!
Surface temperatures can vary greatly from place to place and time to time. In the early morning the temperature at the top of low hill may be 10-15 degrees f warmer than in the creek bottom a half mile away. (Ask a biker).
Also I have left the house when the temperature was below zero f and across town after the wind came up it could be above freezing as a warm air blast move in. Our local radio station is about a mile away and usually they report the same temperature as we have, other times they may be 10- 15 degrees f different.
There are too many variables in surface and I suspect in sea temperatures to make rash conclusions down to 1 degree f or less. Much less trying to project it 100 years into the future.
Let’s face it, as much as we actually know, we don’t know 1/10th as much as we claim to know and half of what we did know a generation ago is forgotten.