There's been a little discussion of a non-peer reviewed (so far) paper published by Anthony Watts et al. claiming the warming at the best-sited US weather stations is two-thirds' that estimated by NOAA for the US based on the entire adjusted weather station record. Sou at HotWhopper (linked above) points out that Watts can't explain why a heat sink or a reflective surface at a station would produce not just a different temperature but a different trend over time. A station with a building next to it might be warmer - that's fine, but why would it then warm up even faster over time?
Victor Venema repeats that issue and also finds fault with Watts' decision to accept one data adjustment while rejecting all others. VV critiques the reliance on potentially-flawed station history metadata to assume a well-sited station has always been well-sited, pointing out that those stations could have been cross-checked with nearby stations. Meanwhile, Watts is holding back on the source data, saying he'll release it only after publication.
My two comments, fwiw. Going back to HotWhopper for a moment, Sou says:
The other point is that it appears that the researchers didn't categorise the weather stations strictly according to Leroy (2010). As far as I can tell, they only categorised them on the proximity of "heat sources or reflective surfaces (buildings, concrete surfaces, car parks etc)". There was no indication that the researchers attempted to group them according to the other criteria described in Leroy (2010), which were the slope of the land, the vegetative cover, proximity to water, and shade.So they exclude siting factors that might make the station warmer (still unclear on why that would result in a different trend) but they include as okay siting factors that might make a station cooler. Vegetative cover and shading in particular might get more significant over time, so maybe that helps explain the differential.
Second, assume for a moment that Watts is right. I learned of the study through one Michael Bastasch at the Daily Caller, beginning with the first sentence:
The National Oceanic and Atmospheric Administration’s reliance on poorly-sited weather stations to calculate surface temperatures is inflating the warming trend of the U.S. and maybe even the rest of the world, according to a landmark study....
What’s more troubling, is that similar siting problems have been observed at weather stations around the world, meaning the global warming present in the surface temperature record may be overblown. Watts’ study comes after NOAA published a June study making further adjustments to temperature data and purported to eliminate the “hiatus” in global warming. Watts’ new paper casts more doubt on NOAA’s temperature adjustments — which always seem to increase the warming trend.
Correcting for these poorly-sited stations could also bring surface warming trends more in line with observations from satellites, which show no statistically significant warming for about two decades.Emphasis added, and nothing Bastasch wrote that is emphasized is actually in the Watts' work that he's reporting. So either Bastasch pulled the global implications of the study out of his own pocket, or somebody he interviewed (Watts?) decided to speculate.
Watts made no attempt to interpret global data, the vast majority of which is ocean data anyway, but if this study was somehow right and somehow had global implications, then the implications is that the globe is warming pretty fast. Watts would be out of the mainstream but still closer to the mainstream than denialists running for the Republican nomination and anyone else who says satellite data prove that surface temps aren't warming. Sou found one of Watts' commenters who noticed this, but Watts himself hasn't.
Finally, strange that the planet wouldn't be warming and absorbing more heat but still (as Tamino says) still confronting steadily rising sea levels. Why is that happening? And why are the vast majority of glaciers melting throughout the last two decades?
Maybe they're poorly sited.