Download Annual Average Temperature Rise: Global Average

Annual Average Temperature Rise: Global Average vs. Average over Land
(The latest draft of this document is available online at http://goo.gl/rsd46S )
By Peter Montague ([email protected]) [Draft of Nov. 29, 2016]
Global average temperature (land and sea combined) has risen about 2 degrees Fahrenheit (1.16
Celsius) since 1750, 1 most it occurring since 1975.
However, global average temperature rise is not the same as average temperature rise over
land, which is where most humans spend most of their time. According to the U.S. National
Aeronautics and Space Administration (NASA), since 1880 the average temperature rise over
land in the U.S. has been at least 50% higher than the global average temperature rise. In
Eurasia, temperature rise over land has been 2 to 3 times as large as the global average
temperature rise, and in northern polar regions, average rise has been 3 to 4 times the global
average. 2
Several other recent studies have reached similar conclusions. 3
1
James Hansen and colleagues at the Earth Institute, Columbia University, report that average global temperature
rise (compared to year 1750) has been 2 °F (1.16 °C) as of early October, 2016; see James Hansen and others,
“Young people’s burden: requirement of negative CO2 emissions,” Manuscript under review for journal Earth
System Dynamics (published October 4, 2016), pg. 10; http://goo.gl/gxmPCy For additional details, see
GISTEMP Team, 2016: GISS Surface Temperature Analysis (GISTEMP). NASA Goddard Institute for Space
Studies. Dataset accessed 2016-10-05 at http://data.giss.nasa.gov/gistemp/; for method of calculation, see J.
Hansen, R. Ruedy, M. Sato, and K. Lo, “Global surface temperature change,” Reviews of Geophysics Vol. 48
(2010), RG4004 [Paper number 2010RG000345], pgs. 1-29. https://goo.gl/DxdWVo
See also S. Solomon, D. Qin, M. Manning, Z. Chen, M. Marquis, K.B. Averyt, M. Tignor and H.L. Miller,
editors, Climate Change 2007: The Physical Science Basis. Contribution of Working Group I to the Fourth
Assessment Report of the Intergovernmental Panel on Climate Change (Cambridge, U.K., and New York, N.Y.,
USA, 2007), pg. 5. http://goo.gl/ZDMF1W
2
J. Hansen, R. Ruedy, M. Sato, and K. Lo, “Global Surface Temperature Change,” Reviews of Geophysics Vol.
48, RG4004 [Paper number 2010RG000345], pgs. 1-29. See pgs. 11-12. http://goo.gl/9skbJa
3
G.A. Meehl, and others, "Global Climate Projections," in Climate Change 2007: The Physical Science Basis.
Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate
Change (S. Solomon and others, eds.) (Cambridge, United Kingdom, and New York, NY, USA, 2007), pgs. 747846; see pg. 749. http://goo.gl/ZDMF1W; Rowan T. Sutton and others, “Land/sea warming ratio in response to
climate change: IPCC AR4 model results and comparison with observations,” Geophysical Research Letters Vol.
34 (2007), L02701. http://goo.gl/1uEApk; Sonia I. Seneviratne and others, “Allowable CO2 emissions based on
regional and impact-related climate targets,” Nature Vol. 529 (Jan. 28, 2016), pgs. 477-483. See, for example,
Supplementary Figure S1c. http://goo.gl/gxmPCy
1
In 2007, the Intergovernmental Panel on Climate Change (IPCC) showed that during the period
1979-2005, annual temperature rise over land was 69% higher than global average annual rise. 4
The National Oceanic and Atmospheric Administration (NOAA) National Center for
Environmental Information (http://goo.gl/N9wVp) shows a similar trend, 2006-2014. (See Table 1,
below, where the NOAA data are summarized.)
Table 1: Global average temperature rise (compared to 20th century average) vs. average
temperature rise over land (compared to 20th century average).
Year
2006
2007
2008
2009*
2010
2011
2012
2013
2014
Average
Global Average
Temperature Rise
above 20th-Century
Average
0.54 °C
0.55 °C
0.49 °C
0.56 °C
0.62 °C
0.51 °C
0.57 °C
0.62 °C
0.69 °C
0.57 °C
Average
Temperature
Rise over Land
0.78 °C
1.02 °C
0.81 °C
0.80 °C
0.96 °C
0.80 °C
0.90 °C
0.99 °C
1.0 °C
0.90 °C
% by which
average over
land exceeds
global average
44%
85%
65%
45%
55%
57%
58%
60%
45%
57%
Source of Data
http://goo.gl/jLCwBC
http://goo.gl/z3oVxj
http://goo.gl/16lXGA
http://goo.gl/RHjZDF
http://goo.gl/odqzBy
http://goo.gl/dMoYnG
http://goo.gl/xhetjL
http://goo.gl/xnDuMa
http://goo.gl/pGPpo9
*2009 data include only 10 months, January through October
Source of data for Table 1: National Oceanic and Atmospheric Administration (NOAA), Center for Environmental
Information (http://goo.gl/N9wVp)
Table 1 shows that, from 2006 through 2014, the annual average temperature rise over land has
been 57% higher than the annual average rise over land and sea combined.
4
S. Solomon, D. Quin, M. Manning, Z. Chen, M. Marquis, K.B. Averyt, M. Tignor and H.L. Miller, editors,
Climate Change 2007: The Physical Science Basis. Contribution of Working Group I to the Fourth Assessment
Report of the Intergovernmental Panel on Climate Change (Cambridge, U.K.: Cambridge University Press, 2007),
pgs. 243 and 248. http://goo.gl/ZDMF1W In table 3.2 on pg. 243 (see the rows marked “Land: Globe”) and table
3.3 on pg. 248 (see the rows marked “Globe”), you can compare the columns marked “1979-2005” in the two
tables. In Table 3.2, if you average the 4 values given (average = 0.244) and compare them to the average of the 3
values in table 3.3 (average = 0.169), you can see that the average rise over land was 69% higher than the average
rise over land and sea combined, 1979-2005.
2
Therefore, it seems warranted to say that, during the past 35 years, average temperature rise over
land in the mid-latitudes (from about 40° N. to about 40° S.) has been at least 50% greater than
global average temperature rise.
3