Last week there was an international media debate on climate data which appeared to be rather surreal to me. It was claimed that the global temperature data had so far shown a “hiatus” of global warming from 1998-2012, which was now suddenly gone after a data correction. So what happened?
One of the data centers that compile the data on global surface temperatures – NOAA – reported in the journal Science on an update of their data. Some artifacts due to changed measurement methods (especially for sea surface temperatures) were corrected and additional data of previously not included weather stations were added. All data centers are continually working to improve their database and they therefore occasionally present version updates of their global series (NASA data are currently at version 3, the British Hadley Centre data at version 4). There is nothing unusual about this, and the corrections are in the range of a few hundredths of a degree – see Figure 1. This really is just about fine details. More »
In a new paper in Science Express, Karl et al. describe the impacts of two significant updates to the NOAA NCEI (née NCDC) global temperature series. The two updates are: 1) the adoption of ERSST v4 for the ocean temperatures (incorporating a number of corrections for biases for different methods), and 2) the use of the larger International Surface Temperature Initiative (ISTI) weather station database, instead of GHCN. This kind of update happens all the time as datasets expand through data-recovery efforts and increasing digitization, and as biases in the raw measurements are better understood. However, this update is going to be bigger news than normal because of the claim that the ‘hiatus’ is no more. To understand why this is perhaps less dramatic than it might seem, it’s worth stepping back to see a little context…
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
B. Huang, V.F. Banzon, E. Freeman, J. Lawrimore, W. Liu, T.C. Peterson, T.M. Smith, P.W. Thorne, S.D. Woodruff, and H. Zhang, "Extended Reconstructed Sea Surface Temperature Version 4 (ERSST.v4). Part I: Upgrades and Intercomparisons", Journal of Climate, vol. 28, pp. 911-930, 2015. http://dx.doi.org/10.1175/JCLI-D-14-00006.1
This month’s open thread. Some interesting trends in ocean heat content, surface temperatures, multiple oddly reported papers (which are often linked to ambiguous press releases…) etc. But at least we aren’t working in political science…
Guest Commentary from Patrick Brown and Wenhong Li, Duke University
We recently published a study in Scientific Reports titled Comparing the model-simulated global warming signal to observations using empirical estimates of unforced noise. Our study seemed to generated a lot of interest and we have received many inquires regarding its findings. We were pleased with some of coverage of our study (e.g., here) but we were disappointed that some outlets published particularly misleading articles (e.g, here, here, and here). Since there appears to be some confusion regarding our study’s findings, we would like to clarify some points (see also MM4A’s discussion).
P.T. Brown, W. Li, E.C. Cordero, and S.A. Mauget, "Comparing the model-simulated global warming signal to observations using empirical estimates of unforced noise", Sci. Rep., vol. 5, pp. 9957, 2015. http://dx.doi.org/10.1038/srep09957
This month’s open thread.
Switch to our mobile site