How Earth’s temperature is reflected on smaller geographic scales Gordon J. Aubrecht, II SOS-AAPT, Saturday 9 March 2013

But what about the “pause” in the rise in T over the past decade?

An important paper was published yesterday in Science.

Fig. 1. Comparison of different methods and reconstructions of global and hemispheric temperature anomalies. (A and B) Globally stacked temperature anomalies for the 5° x 5° area-weighted mean calculation (purple line) with its 1s uncertainty (blue band) and Mann et al.’s global CRUEIV composite mean temperature (dark gray line) with their uncertainty (light gray band). (C and D) Global temperature anomalies stacked using several methods (Standard and Standard 5° x 5° Grid; 30° x 30° Grid; 10-lat: Arithmetic mean calculation, area-weighted with a 5° x 5° grid, area-weighted with a 30° x 30° grid, and area-weighted using 10° latitude bins, respectively; RegEM and RegEM 5° x 5° Grid: Regularized expectation maximization algorithm in filled arithmetic mean and 5° x 5° area-weighted). The gray shading [50% Jackknife (Jack50)] represents the 1 envelope when randomly leaving 50% of the records out during each Monte Carlo mean calculation. Uncertainties shown are 1s for each of the methods.

Compare to Büntgen et al. (2011) T for Europe: 2,500 years Ulf Büntgen, Willy Tegel, Kurt Nicolussi, Michael McCormick, David Frank, Valerie Trouet,, Jed O. Kaplan, Franz Herzig, Karl-Uwe Heussner, Heinz Wanner, Jürg Luterbacher, and Jan Esper, “2500 years of European climate variability and human susceptibility,” Science 331, 578 (2011).

Perhaps you’ve seen articles about the ice-free Arctic this week … and heard that 97% of the GIS surface melted in July …

The “27% rule” says that we use the high 27% and low 27% to distinguish the top from the bottom student exam scores (or of any set of data). This paper says 21%. Note the quote: “Use of 27%, however, is not far from optimal.” (The rule statistics actually say that the range should be 14% to 27%.)

Using the 27% rule …

Monthly anomalies, 27% rule.

Decadal monthly anomalies, 27% rule Decadal monthly anomalies, 27% rule. NOAA & GISS (27% of 133 years → 36 years); HadCRUT4 (27% of 163 years → 44 years). NOAA, upper left; GISS, upper right; HadCRUT4, lower

The three global databases’ decadal anomalies

Top 10 warmest years. NOAA. GISS. HadCRUT4. US. Ohio. 1. 2010. 2010 Top 10 warmest years NOAA GISS HadCRUT4 US Ohio 1 2010 2010 2010 2012 2012 2 2005 2005 2005 1998 1998 3 1998 1998 1998 2006 1921 4 2003 2007 2003 1934 1931 5 2002 2002 2006 1999 1991 6 2006 2003 2009 1921 1949 7 2009 2009 2002 2001 1953 8 2007 2012 2007 2007 1938 9 2004 2006 2012 2005 2006 10 2012 2011 2004 1931 2002 NOAA GISS HadCRU US Ohio this decade 80% 80% 80% 40% 20% preceding decade 20% 20% 20% 30% 20% percent of world area 100% 100% 100% 1.89% 0.02% percent of US area 0.19%

Conclusions: The three global databases agree well with one another (now). The warming signal is inescapable. It is bigger than any other excursion over the past 2500 years.

US temperature history 1.93% of Earth’s area

US decadal temperature history

Where daily record highs were broken or tied in March 2012.

Australia 1.51% of Earth’s area

Australia decadal

Germany 0.07% of Earth’s area

Germany decadal

Ohio 0.23% of Earth’s area

Ohio decadal

English Midlands 0.0056% of Earth’s area

English Midlands, 1850-2012

English Midlands, decadal

Comparisons

Areas relative to Earth: US. 1. 9269% Australia. 1. 5082% Germany Areas relative to Earth: US 1.9269% Australia 1.5082% Germany 0.0700% Ohio 0.0228% English Midlands 0.0056%

Conclusions: There is greater variation in smaller areas of Earth—the smaller the area, the greater the variation. This is the case until about the 1980s. Since 1980, these smaller areas are exhibiting warming similar to one another and to Earth as a whole.