A new analysis of global air temperature by researchers from Tongji University in Shanghai has cast light on the much-debated recent hiatus in global temperature.
Writing in the Journal of Earth Science, the Chinese scientists say there was a rapid rise in global mean surface air temperature after the late 1970s but that this stalled, and there were a relative stagnation and even slight cooling that lasted for about 15 years (1998–2012).
They add that even though the slowdown was acknowledged by the Intergovernmental Panel on Climate Change Fifth Assessment Report (IPCC AR5) and termed as a hiatus (IPCC, 2013), there was a debate in the scientific community about whether there was a hiatus in global warming or not.
The researchers believe that the debate about the global-warming hiatus poses a substantial challenge to our understanding of the global climate response to anthropogenic greenhouse gas emissions and natural variability.
They say that the disagreements about the recent global-warming hiatus mainly arise from different sources, among which differences across observational SAT datasets may be a key contributor to the contradictory conclusions. So they use an alternative set of data.
They use the ratio of two oxygen isotopes in precipitation, oxygen 16 and 18, which is a proxy for the temperature of precipitation and surface temperature.
They are particularly interested in what they term a “robust correlation” between precipitation oxygen ratios and surface temperature over mid- and high-latitude regions.
Twelve stations were selected of which ten are located in Europe, and the remaining two in Antarctica and North America, respectively.
Using the data they constructed a composite isotope index spanning 1970–2016 by combining twelve precipitation oxygen isotope records collected over mid and high-latitude continents. With it, they evaluate the recent global-warming hiatus.
They found a cooling trend over the period 1998–2012 which was significantly different from that of the interval 1970–1997 which is characterized by significant warming. They conclude that,
…our results provide new evidence for recent global warming hiatus and highlight the potential of utilising precipitation isotopes for tracking climate changes.”
Read more at GWPF
I’m sure if you look at this hockey stick graph it will readily explain that 15-year pause…
or not.
Why use land surface when most of the global surface that controls the climate/atmosphere/weather is the liquid surface which also exists in all three phases in the atmosphere and controls our climate by this process, and can be uniformly observed from space directly using a direct. reading radiation thermometer? In case anyone cares in the new consensual science reality, it looks like this. Direct excell chart of the unmodified data.
https://www.dropbox.com/s/b8f596sch58xwka/UAH%20Monthly%20Global%20SSTs%201978-2020.png?dl=0
The actual UAH data is here: I sorted it into a .doc format. It was hard to find the SST (vs. the tropospheric ) data but it IS available on line – in a difficult html format. I can’t find the link or remember who gave it me now! Perhaps someone else can add it?
https://www.dropbox.com/s/6kphv4n1cwax10q/UAH%20Word%20Year%20Mo%20Globe%20%20Land%20Ocean%20%20%20NH%20%20%20Land%20Ocean%20%20%20SH%20%20%20Land%20Ocean%20Trpcs%20%20Land%20Ocean%20NoExt%20%20Land%20Ocean%20SoExt%20%20Land%20Ocean%20NoPol%20%20Land%20Ocean%20SoPol%20%20Land%20Ocean%20USA48%20USA49%20%20AUST%20%201978%2012.doc?dl=0
The over all trend is warming
How serious is it
If it’s that hard to even prove it exists?
We all knew the hiatus was real. After all, to get rid of it they had to “adjust” the past temperature data AGAIN. And even then it couldn’t be entirely eradicated. Besides, the hiatus is probably still underway, as the recent interruption was caused by a particularly strong El Nino – which has nada to do with “global warming” driven by CO2.