How Much Has The Earth Warmed Since Pre-industrial Times?
Bruce Parker
September 30, 2015
This seems like a simple question – just pick a date for the end of “pre-industrial times” and subtract the temperature for that
date from the current temperature. That would work if the Earth’s temperature had increased gradually without too many
“ups and downs”, but a quick look at data from NASA - the estimated yearly (January-December) temperature since 1880
(Figure 11) and various “running means” since 1990 (Figure 22) - shows that the Earth’s temperature varies considerably from
month-to-month, year-to-year, etc. In addition, different scientific organizations have different values for the years 1880-2014
– see Figure 3 (UK Met Office Hadley Centre – HadCrut43) and Figure 4 (IPCC4) and the actual data below.
There was very little total temperature change from about 1880 to 1930, so averaging the temperature over that time period
gives the best “starting point”. Since the Earth’s temperature is expected to continue to increase, the expected 2015
temperature provides the best “ending point”. Table 1 gives the temperature increase for several of the many possible ways of
measuring how much the Earth has warmed (assuming a 2015 temperature of about .81° C above the 1951-1980 base period –
see Figure 55 and .62°C above the base line for the HadCRUT4 data3). In addition, the IPCC reports a “warming of 0.85 [0.65 to
1.06] °C, over the period 1880 to 2012, when multiple independently produced datasets exist” 4. So with an expected increase
of about .16°C from 2012 through 20153, the IPCC estimate for 2015 becomes 1.01°C. It then seems reasonable to assume
that 2015 (or 2016 using the HadCRUT4 data) will be the year in which the temperature increase from pre-industrial times will
first exceed 1°C.
1
Figure 1 – Global Land-Ocean Temperature Index (NASA)
3
Figure 3 – Global Air Temperature Anomaly (HadCRUT4)
2
Figure 2 – Land-Ocean Surface Temperature – Running Means (NASA)
4
Figure 4 Average Annual Land/Ocean Surface Temperature (IPCC)
1
Figure 5 – Progressive Year-To-Date Global Temperatures 1995-20155
NASA6
HadCRUT43
6
# Increase From To Increase From To Description
1. 1.01
-0.2
.81
.85
-0.23 .62 1880 to 2015
2. 1.29
-0.48 .81 1.16
-0.54 .62 1909 to 2015 (lowest annual anomaly since 1880)
3. 1.05
-0.24 .81
.95
-0.33 .62 Average anomaly 1880-1899 to 2015
4. 1.08
-0.27 .81
.96
-0.34 .62 Average anomaly 1880-1929 to 2015
5. 1.12
-0.31 .81
.97
-0.35 .62 Average anomaly 1900-1929 to 2015
Table 1 – Calculations of the temperature increase since pre-industrial times (degrees C)
References
1. http://data.giss.nasa.gov/gistemp/graphs_v3/Fig.A2.gif
(http://data.giss.nasa.gov/gistemp/graphs_v3/)
2. http://www.columbia.edu/~mhs119/Temperature/T_moreFigs/RunningMeans_v4.gif
(http://www.columbia.edu/~mhs119/Temperature/T_moreFigs/)
3. http://www.cru.uea.ac.uk/documents/421974/1295957/Info+sheet+%231.pdf/c612fc7e-babb-463c-b5e3124ac76680c5
2014 estimated anomaly - .563°C. For NASA, the increase from 2014 to 2015 is about .06°C. Applying the same
increase to the HadCrut4 data yields an estimated 2015 anomaly of .623°C.
2012 estimated anomaly - .467°C, so the increase through 2015 is an additional .16°C
4. CLIMATE CHANGE 2013 - The Physical Science Basis (Page 6)
(http://www.ipcc.ch/report/ar5/wg1/)
5. http://thinkprogress.org/climate/2015/09/14/3701298/august-2015-record-warmth/
6. Global Land-Ocean Temperature Index (C) (Anomaly with Base: 1951-1980)
(http://data.giss.nasa.gov/gistemp/graphs_v3/Fig.A2.txt)
2
Temperature Data
Global Temperature Anomalies
Year
1850
1851
1852
1853
1854
1855
1856
1857
1858
1859
1860
1861
1862
1863
1864
1865
1866
1867
1868
1869
1870
1871
1872
1873
1874
1875
1876
1877
1878
1879
1880
1881
1882
1883
1884
1885
1886
1887
1888
1889
1890
1891
HadCRUT4
Global Temperature (Climatic Research Unit)
Anomaly
Smoothed
-0.376
-0.3
-0.222
-0.297
-0.225
-0.297
-0.27
-0.302
-0.247
-0.31
-0.27
-0.323
-0.36
-0.336
-0.457
-0.349
-0.463
-0.36
-0.284
-0.367
-0.341
-0.37
-0.398
-0.368
-0.508
-0.363
-0.28
-0.353
-0.48
-0.34
-0.269
-0.325
-0.24
-0.311
-0.304
-0.3
-0.22
-0.291
-0.256
-0.287
-0.271
-0.285
-0.324
-0.285
-0.228
-0.284
-0.302
-0.281
-0.371
-0.274
-0.408
-0.263
-0.38
-0.249
-0.07
-0.236
0.035
-0.228
-0.229
-0.226
-0.225
-0.233
-0.204
-0.246
-0.212
-0.265
-0.29
-0.285
-0.403
-0.305
-0.385
-0.321
-0.369
-0.334
-0.42
-0.344
-0.314
-0.352
-0.178
-0.358
-0.422
-0.363
-0.342
-0.366
NASA
Annual Mean
-0.21
-0.12
-0.11
-0.21
-0.29
-0.32
-0.32
-0.34
-0.21
-0.12
-0.38
-0.25
5-year Mean
*
*
-0.19
-0.21
-0.25
-0.3
-0.3
-0.26
-0.27
-0.26
-0.25
-0.26
3
1892
1893
1894
1895
1896
1897
1898
1899
1900
1901
1902
1903
1904
1905
1906
1907
1908
1909
1910
1911
1912
1913
1914
1915
1916
1917
1918
1919
1920
1921
1922
1923
1924
1925
1926
1927
1928
1929
1930
1931
1932
1933
1934
1935
1936
1937
1938
-0.461
-0.476
-0.411
-0.396
-0.194
-0.214
-0.414
-0.293
-0.201
-0.268
-0.412
-0.481
-0.528
-0.383
-0.293
-0.474
-0.522
-0.537
-0.497
-0.553
-0.448
-0.438
-0.256
-0.163
-0.397
-0.477
-0.342
-0.282
-0.25
-0.192
-0.309
-0.275
-0.3
-0.219
-0.112
-0.213
-0.213
-0.353
-0.141
-0.089
-0.137
-0.274
-0.13
-0.176
-0.145
-0.028
-0.006
-0.367
-0.364
-0.357
-0.347
-0.337
-0.329
-0.326
-0.33
-0.339
-0.353
-0.37
-0.388
-0.406
-0.423
-0.437
-0.448
-0.454
-0.456
-0.45
-0.439
-0.422
-0.402
-0.382
-0.363
-0.347
-0.331
-0.317
-0.303
-0.291
-0.278
-0.265
-0.254
-0.243
-0.234
-0.224
-0.215
-0.207
-0.198
-0.189
-0.179
-0.167
-0.154
-0.138
-0.12
-0.1
-0.08
-0.059
-0.27
-0.30
-0.31
-0.23
-0.15
-0.12
-0.29
-0.17
-0.09
-0.15
-0.29
-0.36
-0.45
-0.28
-0.23
-0.40
-0.44
-0.48
-0.43
-0.45
-0.35
-0.35
-0.16
-0.11
-0.34
-0.40
-0.26
-0.22
-0.26
-0.21
-0.27
-0.24
-0.28
-0.20
-0.09
-0.21
-0.21
-0.36
-0.14
-0.09
-0.17
-0.28
-0.13
-0.19
-0.15
-0.02
-0.02
-0.3
-0.27
-0.25
-0.22
-0.22
-0.19
-0.16
-0.16
-0.2
-0.21
-0.27
-0.31
-0.32
-0.34
-0.36
-0.36
-0.39
-0.44
-0.43
-0.41
-0.35
-0.28
-0.26
-0.27
-0.25
-0.27
-0.3
-0.27
-0.25
-0.24
-0.25
-0.24
-0.22
-0.2
-0.2
-0.21
-0.2
-0.2
-0.19
-0.21
-0.16
-0.17
-0.18
-0.15
-0.1
-0.08
-0.03
4
1939
1940
1941
1942
1943
1944
1945
1946
1947
1948
1949
1950
1951
1952
1953
1954
1955
1956
1957
1958
1959
1960
1961
1962
1963
1964
1965
1966
1967
1968
1969
1970
1971
1972
1973
1974
1975
1976
1977
1978
1979
1980
1981
1982
1983
1984
1985
-0.056
0.017
0.017
-0.025
-0.002
0.147
0.033
-0.069
-0.042
-0.037
-0.075
-0.175
-0.049
0.031
0.1
-0.13
-0.186
-0.264
-0.003
0.049
0.017
-0.048
0.039
0.017
0.05
-0.222
-0.141
-0.072
-0.076
-0.112
0.03
-0.028
-0.184
-0.068
0.064
-0.211
-0.145
-0.238
0.046
-0.062
0.057
0.093
0.14
0.011
0.19
-0.015
-0.029
-0.04
-0.024
-0.012
-0.005
-0.001
-0.003
-0.009
-0.017
-0.028
-0.037
-0.045
-0.051
-0.056
-0.06
-0.063
-0.065
-0.064
-0.06
-0.053
-0.046
-0.039
-0.035
-0.036
-0.042
-0.05
-0.058
-0.065
-0.07
-0.074
-0.075
-0.076
-0.077
-0.08
-0.081
-0.082
-0.078
-0.07
-0.057
-0.038
-0.016
0.006
0.026
0.044
0.058
0.069
0.081
0.094
-0.03
0.08
0.13
0.10
0.14
0.25
0.12
-0.04
-0.04
-0.10
-0.09
-0.18
-0.07
0.01
0.08
-0.12
-0.14
-0.20
0.03
0.06
0.03
-0.03
0.05
0.03
0.06
-0.20
-0.10
-0.05
-0.02
-0.07
0.07
0.03
-0.09
0.01
0.15
-0.07
-0.01
-0.11
0.19
0.07
0.17
0.28
0.33
0.13
0.31
0.16
0.13
0.03
0.05
0.08
0.14
0.15
0.11
0.09
0.04
-0.03
-0.09
-0.1
-0.09
-0.05
-0.06
-0.05
-0.08
-0.07
-0.08
-0.04
-0.02
0.03
0.03
0.03
-0.02
-0.03
-0.05
-0.06
-0.09
-0.03
-0.01
-0.02
-0.01
0.03
0
0
-0.01
0.03
0.01
0.06
0.12
0.21
0.2
0.24
0.24
0.21
0.18
0.22
5
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
0.046
0.187
0.2
0.12
0.294
0.255
0.104
0.145
0.206
0.323
0.181
0.39
0.535
0.307
0.294
0.439
0.495
0.507
0.448
0.543
0.505
0.493
0.394
0.504
0.555
0.421
0.467
0.492
0.563
0.623+
0.11
0.126
0.144
0.162
0.178
0.194
0.21
0.228
0.249
0.273
0.298
0.325
0.351
0.375
0.398
0.419
0.438
0.453
0.465
0.474
0.479
0.482
0.483
0.485
0.486
0.488
0.489
0.491
0.493
0.19
0.34
0.40
0.29
0.44
0.43
0.23
0.24
0.32
0.46
0.35
0.48
0.63
0.42
0.42
0.55
0.63
0.62
0.55
0.69
0.64
0.66
0.54
0.65
0.72
0.61
0.64
0.66
0.75
0.81#
0.24
0.27
0.33
0.38
0.36
0.33
0.33
0.34
0.32
0.37
0.45
0.47
0.46
0.5
0.53
0.53
0.55
0.61
0.62
0.63
0.62
0.64
0.64
0.64
0.63
0.65
0.67
*
*
*
+ Calculated based on NASA data and “Progressive Year-To-Date Global Temperatures 1995-20155”
# Based on “Progressive Year-To-Date Global Temperatures 1995-20155”
HadCRUT4
NASA
http://www.cru.uea.ac.uk/documents/421974/1295957/Info+sheet+%231.pdf/c612fc7ebabb-463c-b5e3-124ac76680c5
(link on the above page)
http://data.giss.nasa.gov/gistemp/graphs_v3/Fig.A2.txt
6