GetOffYourGas wrote:My interpretation is that Reg claims the effect of CO2 is very minor. He implies that it only causes about 0.001K worth of warming. He doesn't say (in this quote) that the surface of the earth isn't warming, only that it's primarily caused by factors other than CO2.
That's exactly correct. An excellent example is the "blob" that had persisted over the northern Pacific Ocean for a couple of years, blocking the west coast of the United States from getting the water-bearing jet stream and causing the severe drought that occurred there. The surface temperature of the water there was multiple degrees warmer than normal
. People tried to claim that the 'blob" was somehow caused by CO2, but such an idea is utter nonsense, for a variety of reasons:
1) CO2 is well-mixed in the Earth's atmosphere. Had it somehow (magically?) heated the surface of the northern Pacific Ocean by a couple of degrees, it would have ALSO heated the surface of the global oceans EVERYWHERE by the same amount. Clearly the "blob" was caused by a local event, not a global one.
2) The appearance of the "blob" occurred over the course of months. In order to heat that much water by that amount would require massive increases in longwave radiation or upwelling of warm water from below. This can only be accomplished by a reduction in cloud cover over the area or some change in ocean currents.
3) The "blob" disappeared as quickly as it had arrived. If CO2 caused the "blob" to appear, would anyone care to take a crack at the idea of how it made the "blob" go away, given that the CO2 was still there in even higher concentrations?
No, when we measure changes in the temperature of the surface of the global oceans, other factors are by far the dominant causes. There are two primary factors which control the surface temperature of the oceans:
1) Changes in local cloud cover, which modulated how much sunlight reaches the surface of the ocean.
2) Upwelling of warmer or cooler water from deeper within the ocean.
Both of those factors can rapidly change the temperature of the surface of the ocean. We see the second factor at work frequently in the operation of El Ninos.