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Assume the surface temperature stations are measuring the first 2 meters of the atmosphere(* but see below). The density of air at the surface is 1.2 kg/m3. So the total mass of the 2-meter sliver is ~ 1015 kg.
It has a heat capacity of about 1000 J/kgK, so it takes ~ 1016 Joules to create a 0.02°C temperature rise in this 2-meter sliver of the atmosphere, which is ~50 J/m2 over the Earth's surface.
50 Joules isn't much. It's ~ 10-5 kilowatt-hours -- about how much electricity the average American uses (12,900 kWh/yr) in 30 milliseconds.
If that 0.02°C of warming happens over 4 years, and if I've not made any mistakes, the average heating rate is 0.4 microwatts per square meter. By contrast, the average surface heat flux from the Earth's interior heat is 86 milliwatts per square meter -- 200,000 times higher.
(But the average heat flux from the Earth's interior is essentially constant, so it doesn't create global warming or global cooling.)
(*) OK, in reality the sensors that measure temperature are very small -- this one (page 18) is about 5 mm x 4 mm. So it's only measuring a 0.5 cm-thick slice of the atmosphere. That would require only 0.1 J/m2, or, over four years about 1 nanowatt per square meter.
So crowing over these types of records -- 0.02°C -- just opens up a world of "yeah, but"'s. It would be more scientific to say, as Roger Pielke Sr tweeted today (and has emphasized for years):
Re:global warming, changes in ocean heat should be used, NOT global average sfc temp trend http://t.co/3GBVC6gsny pic.twitter.com/0qDbtwMwab
— Roger A. Pielke Sr (@RogerAPielkeSr) January 20, 2015
As he wrote in Physics Today in 2008:
How much heat can a 2-dimensional surface hold? Zero. Not much lower than can a 2-dimensional surface with a 5 mm-thick layer of air on top of it.
Of course, all NOAA and NASA (and all other) climate scientists know all of this. But try explaining this to the public -- or even to a teleconference full of journalists. And good luck explaining that you really haven't measured the temperature change of the Earth's surface, but the temperature change of your model of the Earth's surface. The public would never get it, and the usual suspects would certainly take it as an opening for all kinds of purposeful confusion and dissembling denialism.
Last word? It's the trend, stupid.
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