Quite often you will here Nova comment about the “missing hotspot” as if this were evidence against global warming. It’s not. For intricate details of why, please see previous explanations (1, 2, 3, 4, 5, 6, 7, 8). For a simple summary … Initially Nova made some bold claims in her first handbook.
The greenhouse signature is missing. Weather balloons have scanned the skies for years but can find no sign of the telltale “hot spot” warming patter that greenhouse gases would leave. There’s not even a hint. Something else caused the warming.
Nova’s inexperience in the field of climate science is displayed once more.
Signature of Warming vs Signature of Greenhouse Gas
The hotspot is not the signature of greenhouse gas, it’s a signature of surface warming and can be caused by anything that warms the surface. Realclimate showed this best by modelling the expected warming from an additional 2% solar output vs that of doubled CO2. The hotspot appears in both cases, not just from greenhouse gases. It is not a signature of greenhouse gas, but an expected result of surface warming. The major difference between the two images is the stratospheric cooling, the purple cold patch in the top of the left hand image.
The real “signature” of greenhouse gas related warming is the cooling of the stratosphere, and that is cooling, although the effect due to greenhouse gases is masked by the effect from ozone depletion. Read more here if you’re so inclined.
What’s the Hot Spot?
So what is the “Hot Spot” if it’s not a signature of greenhouse warming?
Does the Hot Spot Exist?
Jo’s claim that weather balloons find NO SIGN is more than a little exaggerated. When stitching together radiosonde temperature data from different systems, the hotspot shows up in seasonal and annual scales but not on decadal timescales. When using estimates based upon wind shear, which does not suffer the same problems temperature data does, then the hot spot does appear.
Of course our cherry picking Nova will exclude the science that finds the hotspot and only consider the science that supports her own beliefs.
But in the end, even if the hot spot didn’t eventuate, that means the models, on this account, would be incorrect. It does not mean that the planet isn’t warming, we already know from multiple lines of evidence that the planet IS warming and that it is due to mankind’s activities.
Tags: Hot Spot