Sunday, May 8, 2011

Are Sea Levels Rising or Falling?

Recently, I wrote a guest post (see link) on Anthony Watts’ world-class blog, WattsUpWithThat.com, the topic of which was a recent round of lawsuits (proposed and actual) related to climate change. In my writing, I made the statement that many dire events are predicted by the warmists when (if) the Earth’s climate becomes hotter due to man-made global warming. I wrote: (bold emphasis added for this post, not included in the original on WUWT)
A greatly hotter planet is predicted to have dire consequences. Among the predicted events are millions of climate refugees, massive reduction in coral reefs due to ocean acidification, inundated seashores from rising sea levels, with the sea level increase caused by hotter ocean water and melted polar ice caps, frequent and unusually strong hurricanes or tropical cyclones, weather too hot to grow crops, prolonged and devastating heat waves, and outbreaks of heat-related diseases and the attendant deaths.” I then wrote “ The fact that CO2 has risen over the past 50 years, yet none of the dire events have occurred surely will not be overlooked by the defense attorneys. The facts that CO2 continues to rise, and the global and regional temperatures are falling, and the ocean levels are falling, and the ocean temperatures are falling, also will surely be emphasized by the defense attorneys.”
A reader then took exception to one phrase, “. . . and the ocean levels are falling, . . .” He or she challenged me to support that statement with evidence. So, I did. I wrote:
. . . the sea level data from sealevel.Colorado.edu shows a mix of ocean level trends, with some point locations rising, but some falling since the satellite measurements began in 1992. For example, my previous investigations for the data along the California coast shows a decrease in sea levels, not an increase. However, even the global mean sea level trend has stabilized since 2006, and shows a slight downward trend in some of the individual ocean basins. For example, the trend for the Pacific Ocean shows +0.23 mm/year since the end of 2005. However, there is a significant spike in the data for the last half of 2009, which is highly questionable as to its accuracy. Without that data spike, the trend since 2005 shows a decrease of (minus) -0.18 mm/year. By “without that spike,” my meaning is to manually adjust the data downward by 10 mm, starting with the data point labeled 2009.5741 and ending with 2009.927. This hand-correction opens up a can of worms, as criticism can be leveled at why should the correction be made only for those data points, and why choose 10 mm as the adjustment? Why not make similar adjustments to low-lying data?

My response to those arguments is that the data appears to have outliers, far beyond the normal range of data oscillations. In my professional experience as an engineer, such outliers deserve special attention to determine several things. First, do they indicate a problem with the measuring instruments? Second, if there are no instrument problems, was there a data transmission or recording or transcription error? Third, if none of those problems exist, and given what we know to be true in physics and engineering, is it physically possible, or even probable, that such a change in the measured parameter could happen in such a short time? Fourth, when a trend over time is the critical question, what is the impact of having the outlier included, and then excluded in that trend calculation? This last question is especially critical when the outlier cannot be explained.
This is a long way of saying that I don’t for a minute believe there was an upward spike in the actual sea level in the last half of 2009, across the entire Pacific Ocean. We may never know, of course, as it is impossible to go back in time to take the measurements again. We cannot repeat the experiment, in other words. Therefore, everyone can make of this what they choose. Some, of course, will disagree with me and they have every right to do so. I can see an inflection point in the global mean sea level trend, somewhere around the middle of 2005, as many others have noted and written on. What was a clearly rising trend suddenly became a zero trend, or with a slight declining trend if the apparently spurious spike in 2009 is taken away.
Thus, my statement that the ocean levels are falling. And, this is occurring even with a continuing increase in CO2. As developing economies consume greater quantities of coal, the increase in CO2 should escalate. If the warmists were correct, ocean levels should be rising at a greater rate. Clearly, they are not. Such evidence would be great fun to present in a court of law.
Here, I will present the graphical support for the statements and conclusions above. Figure 1 (below) shows the sea level anomalies for the Pacific Ocean Basin since 1992, from the above-mentioned source, sealevel.colorado.edu as of May 4, 2011. The straight-line trend shows an average increase of 2.59 mm/year, or 259 mm per century. For Americans, that works out to barely more than 10 inches in a century; one inch per decade. (254 mm would be 10 inches, so this is only 5 mm more than 10 inches).



Figure 1
Pacific Ocean Basin Mean Sea Level Anomalies and Trend
(click on chart for larger version)

However, Figure 1 has a most interesting aspect. There is a definite break in the upward trend starting in mid-2005. From that point forward, the sea level rise has essentially stopped, and appears to be decreasing. Therefore, I plotted out only the data since 2005 (see Figure 2). The linear trend of Figure 2 is +0.23 mm/year, or 23 mm per century. That is barely less than one inch.

But, an even more intriguing aspect exists for Figure 2. There is an upward “bump” in the data in the final six months of 2009, which appears somewhat odd. I referred to this above as a “significant spike” in the data.


Figure 2
Pacific Ocean Basin Mean Sea Level Anomalies and Trend
Since 2005
(click on chart for larger version)

As shown in Figure 3, the “significant spike” was adjusted downward manually. With this adjustment, the linear trend is downward, or (minus) -0.18 mm/year, or 18 mm per century.


Figure 3
Pacific Ocean Basin Mean Sea Level Anomalies and Trend
Since 2005, Adjusted Last Half of 2009
(click on chart for larger version)

In conclusion, the satellite data shows that something significant, something unusual, occurred in the end of 2005. The generally upward trend, slight though it was at approximately 2.6 mm per year, made an abrupt switch. That significant something indicates the ocean levels are no longer increasing. From a climate change perspective, and especially the catastrophic Global Warming predictions, this is an important event.

Roger E. Sowell, Esq.
Marina del Rey, California



Below are the data that was used in the above charts. The first column, "year" shows the year with the week indicated after the decimal. The second column, "msl_ib(mm)" shows the mean sea level (msl) anomaly as measured in millimeters (mm). Where there is a third column, the data is the value after manually subtracting 10 from the mean sea level quantity.
year msl_ib(mm) #version_2011_rel1
1992.9323 -1.486
1992.9595 -5.771
1992.9866 -25.939
1993.0138 -27.168
1993.0409 -31.424
1993.0681 -26.150
1993.0952 -29.214
1993.1223 -17.263
1993.1495 -20.071
1993.1766 -19.212
1993.2038 -16.808
1993.2309 -2.934
1993.2581 -17.298
1993.2852 -11.920
1993.3124 -7.738
1993.3395 -17.114
1993.3667 -19.102
1993.3938 -17.776
1993.4210 -8.777
1993.4481 -11.516
1993.4753 -4.756
1993.5024 -8.066
1993.5296 -8.458
1993.5567 -14.213
1993.5839 -5.229
1993.6110 2.473
1993.6382 -3.918
1993.6653 -8.046
1993.6925 -3.971
1993.7196 -4.677
1993.7468 -2.375
1993.7739 -1.457
1993.8010 -3.732
1993.8282 -2.044
1993.8553 -19.762
1993.8825 -11.975
1993.9096 -2.466
1993.9368 -7.063
1993.9639 -3.717
1993.9911 -10.801
1994.0182 -12.038
1994.0454 -6.875
1994.0725 -5.255
1994.0997 -17.532
1994.1268 -17.331
1994.1540 -28.244
1994.1811 -7.218
1994.2083 -15.977
1994.2354 -7.343
1994.2626 -10.297
1994.2897 -11.519
1994.3169 -9.268
1994.3440 -17.643
1994.3712 -16.789
1994.3983 -25.515
1994.4255 -16.652
1994.4526 -13.122
1994.4798 -21.699
1994.5069 -9.741
1994.5340 2.584
1994.5612 1.977
1994.5883 -6.170
1994.6155 -9.692
1994.6426 -0.417
1994.6698 -5.553
1994.6969 0.574
1994.7241 1.651
1994.7512 -13.184
1994.7784 -13.052
1994.8055 -1.527
1994.8327 -4.111
1994.8598 -3.466
1994.8870 -11.701
1994.9141 -19.910
1994.9413 -12.198
1994.9684 -6.225
1994.9956 -8.456
1995.0227 -12.520
1995.0499 -7.632
1995.0770 2.084
1995.1042 -7.986
1995.1313 -16.003
1995.1585 -20.015
1995.1856 -1.545
1995.2128 1.991
1995.2399 -19.846
1995.2670 -21.026
1995.2942 -18.411
1995.3213 -12.348
1995.3485 -28.584
1995.3756 -23.496
1995.4028 -17.048
1995.4299 -23.640
1995.4571 -18.013
1995.4842 -8.506
1995.5114 -2.396
1995.5657 -11.279
1995.5928 -8.463
1995.6200 -11.265
1995.6471 -6.019
1995.6743 -5.051
1995.7014 2.060
1995.7286 -4.240
1995.7557 -11.793
1995.7829 -2.624
1995.8100 -16.228
1995.8372 -8.110
1995.8643 -7.071
1995.8915 -9.104
1995.9458 -17.448
1995.9729 -14.554
1996.0000 -12.533
1996.0272 -25.578
1996.0543 -21.023
1996.0815 -19.339
1996.1086 -9.820
1996.1358 -4.298
1996.1629 -12.155
1996.1901 -18.272
1996.2172 -17.852
1996.2444 -16.229
1996.2715 -11.495
1996.2987 -5.392
1996.3258 -7.383
1996.3530 -17.568
1996.3801 -15.233
1996.4073 -24.187
1996.4344 -6.655
1996.4616 -10.022
1996.4887 -1.090
1996.5159 -11.351
1996.5430 -3.120
1996.5702 1.027
1996.5973 7.756
1996.6245 -1.135
1996.6516 3.761
1996.6788 6.628
1996.7059 0.862
1996.7330 -0.286
1996.7602 0.077
1996.7873 -12.093
1996.8145 -2.468
1996.8416 2.250
1996.8688 -3.316
1996.8959 -15.110
1996.9231 -7.431
1996.9502 -6.337
1996.9774 -1.417
1997.0045 -8.540
1997.0317 -23.637
1997.0588 -27.977
1997.0860 -7.600
1997.1131 -19.916
1997.1403 2.822
1997.1674 -11.162
1997.1946 -14.802
1997.2217 -13.449
1997.2489 2.620
1997.2760 4.502
1997.3032 -8.379
1997.3303 -9.565
1997.3575 -12.882
1997.3846 -9.367
1997.4118 5.056
1997.4389 0.033
1997.4660 2.361
1997.4932 -0.987
1997.5203 4.889
1997.5475 9.102
1997.5746 22.517
1997.6018 7.607
1997.6289 16.499
1997.6561 7.891
1997.6832 5.615
1997.7104 11.960
1997.7375 28.554
1997.7647 14.698
1997.7918 12.168
1997.8190 9.296
1997.8461 4.881
1997.8733 3.700
1997.9004 9.248
1997.9276 17.072
1997.9547 4.089
1997.9819 7.660
1998.0090 -4.219
1998.0362 1.530
1998.0633 -7.962
1998.0905 7.657
1998.1176 1.009
1998.1448 -3.447
1998.1719 -14.055
1998.1990 -7.810
1998.2262 -2.120
1998.2533 2.024
1998.2805 -5.206
1998.3076 -6.432
1998.3348 -2.764
1998.3619 -15.602
1998.3891 -17.663
1998.4162 6.065
1998.4434 8.740
1998.4705 -6.931
1998.4977 -10.119
1998.5248 -15.512
1998.5520 -10.138
1998.5791 -18.846
1998.6063 1.604
1998.6334 -10.658
1998.6606 -9.011
1998.6877 -6.899
1998.7149 -4.434
1998.7420 6.578
1998.7692 3.433
1998.7963 -23.800
1998.8235 -9.777
1998.8506 -1.830
1998.8777 13.178
1998.9049 0.387
1998.9320 10.445
1998.9592 -13.730
1998.9863 -11.690
1999.0135 -13.324
1999.0406 4.443
1999.0678 -20.479
1999.0949 -8.997
1999.1221 -10.664
1999.1492 -11.500
1999.1764 -4.696
1999.2035 -11.470
1999.2307 19.950
1999.2578 6.461
1999.2850 -12.132
1999.3121 -11.087
1999.3393 -3.948
1999.3664 -9.701
1999.3936 -5.175
1999.4207 1.612
1999.4479 -3.482
1999.4750 -5.375
1999.5022 -3.170
1999.5293 -0.353
1999.5565 11.188
1999.5836 -5.150
1999.6107 -0.195
1999.6379 4.151
1999.6650 -9.725
1999.6922 8.222
1999.7193 14.343
1999.7465 8.878
1999.7736 14.397
1999.8008 8.236
1999.8279 10.616
1999.8551 11.801
1999.8822 8.111
1999.9094 -0.531
1999.9365 -8.548
1999.9637 3.986
1999.9908 4.432
2000.0180 -0.565
2000.0451 -8.416
2000.0723 -6.039
2000.0994 -12.676
2000.1266 -5.719
2000.1537 9.891
2000.1809 4.080
2000.2080 7.529
2000.2352 9.674
2000.2623 -25.511
2000.2895 -3.363
2000.3166 -1.585
2000.3437 6.222
2000.3709 -5.692
2000.3980 -11.024
2000.4252 -8.984
2000.4523 -0.897
2000.4795 7.830
2000.5066 9.358
2000.5338 14.725
2000.5609 -3.741
2000.5881 -3.509
2000.6152 13.350
2000.6424 16.318
2000.6695 15.923
2000.6967 20.860
2000.7238 14.314
2000.7510 16.200
2000.7781 22.300
2000.8053 14.957
2000.8324 13.796
2000.8596 16.710
2000.8867 9.220
2000.9139 17.346
2000.9410 10.647
2000.9682 12.717
2000.9953 14.890
2001.0225 2.224
2001.0496 -4.476
2001.0767 -6.792
2001.1039 1.999
2001.1310 5.674
2001.1582 11.634
2001.1853 4.292
2001.2125 6.119
2001.2396 9.107
2001.2668 9.753
2001.2939 14.194
2001.3211 15.772
2001.3482 2.419
2001.3754 5.291
2001.4025 0.608
2001.4297 4.637
2001.4568 8.147
2001.4840 16.470
2001.5111 16.674
2001.5383 16.058
2001.5654 8.362
2001.5926 22.418
2001.6197 30.018
2001.6469 19.201
2001.6740 15.256
2001.7012 21.082
2001.7283 21.512
2001.7555 22.435
2001.7826 19.299
2001.8097 17.283
2001.8369 14.945
2001.8640 6.213
2001.8912 13.794
2001.9183 13.543
2001.9455 17.139
2001.9726 6.399
2001.9998 0.661
2002.0269 -4.249
2002.0541 3.636
2002.0812 4.086
2002.1084 9.182
2002.1355 8.188
2002.1627 2.279
2002.1898 -0.072
2002.2170 11.181
2002.2441 16.766
2002.2713 20.688
2002.2984 9.809
2002.3256 7.105
2002.3527 8.923
2002.3799 16.298
2002.4070 13.147
2002.4342 13.951
2002.4613 9.205
2002.4885 33.801
2002.5156 32.310
2002.5427 23.925
2002.5699 31.002
2002.5970 20.790
2002.6242 31.008
2002.6513 24.038
2002.6785 20.451
2002.7056 22.940
2002.7328 25.659
2002.7599 28.961
2002.7871 28.605
2002.8142 40.830
2002.8414 28.113
2002.8685 36.796
2002.8957 37.708
2002.9228 31.883
2002.9500 21.026
2002.9771 13.672
2003.0043 17.140
2003.0314 14.896
2003.0586 16.558
2003.0857 23.254
2003.1129 14.095
2003.1400 5.103
2003.1672 15.592
2003.1943 12.493
2003.2214 16.062
2003.2486 17.145
2003.2757 15.688
2003.3029 14.643
2003.3300 -2.371
2003.3572 6.656
2003.3843 21.598
2003.4115 17.099
2003.4386 8.932
2003.4658 0.599
2003.4929 -1.904
2003.5201 14.773
2003.5472 24.663
2003.5744 21.987
2003.6015 22.827
2003.6287 15.495
2003.6558 27.129
2003.6830 34.483
2003.7101 29.843
2003.7373 17.824
2003.7644 22.696
2003.7916 21.445
2003.8187 16.681
2003.8459 16.059
2003.8730 22.121
2003.9002 30.394
2003.9273 24.145
2003.9544 16.364
2003.9816 18.559
2004.0087 16.115
2004.0359 14.764
2004.0630 13.711
2004.0902 13.886
2004.1173 10.665
2004.1445 24.145
2004.1716 24.532
2004.1988 21.958
2004.2259 18.275
2004.2531 25.585
2004.2802 18.355
2004.3074 28.265
2004.3345 6.751
2004.3617 16.021
2004.3888 31.001
2004.4160 17.824
2004.4431 13.313
2004.4703 16.578
2004.4974 27.053
2004.5246 35.658
2004.5517 30.882
2004.5789 20.432
2004.6060 20.551
2004.6332 22.091
2004.6603 27.025
2004.6874 31.066
2004.7146 31.953
2004.7417 22.671
2004.7689 22.977
2004.7960 26.029
2004.8232 25.597
2004.8503 19.157
2004.8775 34.075
2004.9046 19.000
2004.9318 19.071
2004.9589 21.288
2004.9861 22.863
2005.0132 9.980
2005.0404 7.564
2005.0675 17.231
2005.0947 21.605
2005.1218 24.175
2005.1490 27.218
2005.1761 31.271
2005.2033 24.516
2005.2304 1.163
2005.2576 10.944
2005.2847 22.766
2005.3119 8.722
2005.3390 14.094
2005.3662 24.647
2005.3933 18.498
2005.4204 13.527
2005.4476 10.517
2005.4747 28.728
2005.5019 33.957
2005.5290 20.532
2005.5562 26.893
2005.5833 35.955
2005.6105 19.034
2005.6376 20.821
2005.6648 36.776
2005.6919 43.582
2005.7191 35.716
2005.7462 24.423
2005.7734 34.436
2005.8005 42.993
2005.8277 44.890
2005.8548 39.958
2005.8820 41.181
2005.9091 28.913
2005.9363 21.455
2005.9634 32.159
2005.9906 40.387
2006.0177 27.457
2006.0449 15.249
2006.0720 20.739
2006.0992 27.078
2006.1263 24.080
2006.1534 20.989
2006.1806 29.243
2006.2077 14.859
2006.2349 20.911
2006.2620 20.724
2006.2892 26.006
2006.3163 11.493
2006.3435 18.458
2006.3706 14.947
2006.3978 13.771
2006.4249 17.823
2006.4521 21.147
2006.4792 27.871
2006.5064 26.496
2006.5335 24.825
2006.5607 25.118
2006.5878 33.534
2006.6150 30.139
2006.6421 27.590
2006.6693 25.275
2006.6964 29.346
2006.7236 39.852
2006.7507 38.106
2006.7779 36.168
2006.8050 31.744
2006.8321 16.974
2006.8864 31.352
2006.9136 23.923
2006.9407 29.740
2006.9679 23.080
2006.9950 17.493
2007.0222 22.334
2007.0493 16.642
2007.0765 23.088
2007.1036 21.522
2007.1308 23.301
2007.1579 23.528
2007.1851 20.336
2007.2122 14.105
2007.2394 16.908
2007.2665 19.075
2007.2937 28.294
2007.3208 16.378
2007.3480 23.531
2007.3751 18.976
2007.4023 22.323
2007.4294 10.762
2007.4566 23.032
2007.4837 14.731
2007.5109 22.903
2007.5380 18.037
2007.5651 23.751
2007.5923 31.015
2007.6194 30.765
2007.6466 20.630
2007.6737 19.297
2007.7009 27.876
2007.7280 34.705
2007.7552 31.855
2007.7823 25.394
2007.8095 18.442
2007.8366 20.701
2007.8638 34.582
2007.8909 35.878
2007.9181 26.700
2007.9452 21.755
2007.9724 16.414
2007.9995 21.419
2008.0267 27.400
2008.0538 22.421
2008.0810 19.235
2008.1081 9.821
2008.1353 21.663
2008.1624 20.260
2008.1896 20.054
2008.2167 20.441
2008.2439 19.659
2008.2710 25.040
2008.2981 10.276
2008.3253 10.937
2008.3524 20.728
2008.3796 27.421
2008.4067 16.943
2008.4339 24.858
2008.4610 25.867
2008.4882 20.712
2008.5153 20.091
2008.5425 23.795
2008.5696 27.041
2008.5968 34.364
2008.6239 30.966
2008.6511 25.322
2008.6782 33.336
2008.7054 26.113
2008.7325 30.574
2008.7597 24.234
2008.7868 25.791
2008.8140 15.091
2008.8411 17.223
2008.8683 19.665
2008.8954 8.434
2008.9226 27.964
2008.9497 20.110
2008.9769 17.634
2009.0040 26.878
2009.0311 34.380
2009.0583 35.118
2009.0854 9.161
2009.1126 15.858
2009.1397 15.744
2009.1669 16.353
2009.1940 13.617
2009.2212 17.307
2009.2483 25.272
2009.2755 16.205
2009.3026 21.752
2009.3298 28.892
2009.3569 22.549
2009.3841 17.170
2009.4112 12.563
2009.4384 13.766
2009.4655 19.241
2009.4927 20.233
2009.5198 26.375
2009.5470 24.946
2009.5741 46.189 36.189
2009.6013 33.244 23.244
2009.6284 33.593 23.593
2009.6556 45.974 35.974
2009.6827 48.901 38.901
2009.7099 40.834 30.834
2009.7370 48.690 38.690
2009.7642 28.640 18.640
2009.7913 31.518 21.518
2009.8184 33.004 23.004
2009.8456 38.716 28.716
2009.8727 38.035 28.035
2009.8999 34.541 24.541
2009.9270 37.662 27.662
2009.9542 28.762
2009.9813 32.680
2010.0085 32.065
2010.0356 37.049
2010.0628 23.005
2010.0899 23.308
2010.1171 20.713
2010.1442 27.327
2010.1714 25.586
2010.1985 21.481
2010.2257 18.349
2010.2528 27.833
2010.2800 22.848
2010.3071 32.387
2010.3343 27.573
2010.3614 23.300
2010.3886 20.300
2010.4157 20.899
2010.4429 12.568
2010.4700 24.594
2010.4971 14.379
2010.5243 21.078
2010.5514 11.878
2010.5786 29.669
2010.6057 18.464
2010.6329 27.665
2010.6600 22.737
2010.6872 13.456
2010.7143 11.011
2010.7415 23.017
2010.7686 19.647
2010.7958 22.741
2010.8229 27.406
2010.8501 28.889
2010.8772 17.497
2010.9044 15.599
2010.9315 21.153
2010.9587 30.305
2010.9858 22.007
2011.0130 25.324
2011.0401 16.801
2011.0673 19.673


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