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There was no pause

Filed under: — rasmus @ 22 January 2017

I think that the idea of a pause in the global warming has been a red herring ever since it was suggested, and we have commented on this several times here on RC: On how data gaps in some regions (eg. the Arctic) may explain an underestimation of the recent warming. We have also explained how natural oscillations may give the impression of a faux pause. Now, when we know the the global mean temperature for 2016, it’s even more obvious.

Easterling and Wehner (2009) explained that it is not surprising to see some brief periods with an apparent decrease in a temperature record that increases in jumps and spurts, and Foster and Rahmstorf (2012) showed in a later paper how temperature data from the most important observations show consistent global warming trends when known short-term influences such as El Niño Southern oscillation (ENSO), volcanic aerosols and solar variability are accounted for.

A recent paper by Hausfather et al. (2017) adds little new to our understanding, although it confirms that there has not been a recent “hiatus” in the global warming. However, if there are doubts about a physical condition, then further scientific research is our best option for establishing the facts. This is exactly what this recent study did.

The latest findings confirm the results of Karl et al. 2015 from the National Oceanic Atmospheric Administration (NOAA), which Gavin described in a previous post here on RC. The NOAA analysis received unusual attention because of the harassment it drew from the chair of the US House Science Committee and the subpoena demand for emails.

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References

  1. D.R. Easterling, and M.F. Wehner, "Is the climate warming or cooling?", Geophysical Research Letters, vol. 36, 2009. http://dx.doi.org/10.1029/2009GL037810
  2. G. Foster, and S. Rahmstorf, "Global temperature evolution 1979–2010", Environmental Research Letters, vol. 6, pp. 044022, 2011. http://dx.doi.org/10.1088/1748-9326/6/4/044022
  3. Z. Hausfather, K. Cowtan, D.C. Clarke, P. Jacobs, M. Richardson, and R. Rohde, "Assessing recent warming using instrumentally homogeneous sea surface temperature records", Science Advances, vol. 3, pp. e1601207, 2017. http://dx.doi.org/10.1126/sciadv.1601207
  4. T.R. Karl, A. Arguez, B. Huang, J.H. Lawrimore, J.R. McMahon, M.J. Menne, T.C. Peterson, R.S. Vose, and H. Zhang, "Possible artifacts of data biases in the recent global surface warming hiatus", Science, vol. 348, pp. 1469-1472, 2015. http://dx.doi.org/10.1126/science.aaa5632

2016 Temperature Records

Filed under: — gavin @ 19 January 2017

To nobody’s surprise, all of the surface datasets showed 2016 to be the warmest year on record.



Barely more surprising is that all of the tropospheric satellite datasets and radiosonde data also have 2016 as the warmest year.



Coming as this does after the record warm 2015, and (slightly less definitively) record warm 2014, the three records in row might get you to sit up and pay attention.

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The NASA data conspiracy theory and the cold sun

When climate deniers are desperate because the measurements don’t fit their claims, some of them take the final straw: they try to deny and discredit the data.

The years 2014 and 2015 reached new records in the global temperature, and 2016 has done so again. Some don’t like this because it doesn’t fit their political message, so they try to spread doubt about the observational records of global surface temperatures. A favorite target are the adjustments that occur as these observational records are gradually being vetted and improved by adding new data and eliminating artifacts that arise e.g. from changing measurement practices or the urban heat island effect. More about this is explained in this blog article by Victor Venema from Bonn University, a leading expert on homogenization of climate data. And of course the new paper by Hausfather et al, that made quite a bit of news recently, documents how meticulously scientists work to eliminate bias in sea surface temperature data, in this case arising from a changing proportion of ship versus buoy observations. More »

Climatology and meteorology are your friends

The Norwegian Meteorological institute has celebrated its 150th anniversary this year. It was founded to provide weather data and tentative warnings to farmers, sailors, and fishermen. The inception of Norwegian climatology in the mid-1800s started with studies of geographical climatic variations to adapt important infrastructure to the ambient climate. The purpose of the meteorology and climatology was to protect lives and properties.

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Predicting annual temperatures a year ahead

Filed under: — gavin @ 16 September 2016

I have a post at Nate Silver’s 538 site on how we can predict annual surface temperature anomalies based on El Niño and persistence – including a (by now unsurprising) prediction for a new record in 2016 and a slightly cooler, but still very warm, 2017.

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