Comments on: Sea Levels May Rise Faster Than Expected

By: David Burton

David Burton — Sun, 25 Mar 2012 10:24:00 +0000

Paul, the difference between 3.2 mm/yr and 1.2 mm/yr does not represent an increase in the rate of sea level rise. It represents an apples-to-oranges comparison between Topex/Poseidon & Jason satellite measurements of sea level rise averaged over the open ocean (circa 1993-2005) for the 3.2 mm/year figure, and pre-1993 averaged coastal tide gauge measurements for the 1.2 mm/year figure.

Those two numbers come from measuring the rate of sea level rise at different locations!

To reach a valid conclusion about whether the rate of SLR is increasing or decreasing, it is necessary to compare measurements at the same locations.

Sea levels rise and fall at different rates in different locations, due to local effects, and because the “solid” surface of the earth is actually moving: it floats on a big ball of viscous molten magma, which is slowly sloshing. In some places, sea level is rising at a rate of several mm/year. In other places sea level is rising at a much slower rate, or even falling.

So if you measure the rate of sea level rise at one location (or one set of locations), for one time period, and compare it to the rate of sea level rise at a different location for a different time period, you can create the illusion of acceleration, even if the rate of sea level rise has actually not changed at all at either location.

That’s what you’re doing when you compare the recent satellite-measured 3.2 mm/year rate of sea level rise in the open ocean to averaged coastal tide gauge measurements from 50 or 70 years ago.

Coastal tide gauges show that the rate of SLR has not accelerated at all in the last 70 years (i.e., over the time period when humans have contributed significantly to CO2 levels). The geographically-weighted average rate of sea level rise from the best GLOSS-LTT tide gauges is only about 1.1 mm/year, unless you add GIA fudge factors or similar “corrections.” (If you calculate a simple, unweighted average, it’s even lower.)

We only have 19 years of satellite data, but the early satellite data showed a rate of about 3.2 mm/year sea level rise (though the satellites are now showing a much lower rate). That’s where your “3.2 mm/year” number comes from. But averaged GLOSS-LTT tide gauges have always shown a much lower rate: about 1.1 to 1.2 mm/year if you don’t add GIA fudge factors.

If you compare 1.2 (or “adjusted” 1.7) mm/year from tide gauges to 3.2 mm/year from satellites, you create an illusion of acceleration, even though the rate of SLR hasn’t increased at all. But if you compare apples-to-apples, you can easily see that the rate of sea level rise has not increased in response to anthropogenic CO2.

Dave Burton
Cary

By: David Burton

David Burton — Sun, 25 Mar 2012 09:58:00 +0000

This article misrepresents what what the scientific evidence tells us about sea level. The current rate of sea level rise is miniscule, but alarmists predict dramatically accelerated sea level rise because they think that meltwater from Greenland and Antarctica might increase the rate of sea level rise.That’s contrary to the best scientific evidence. Greenland is colder now than it was in the 1930s and 1940s, and much colder than during the Medieval Warm Period (800-1100 years ago), neither of which saw substantial sea level rise.Antarctic ice melt won’t drive up sea level, either. Even the alarmist IPCC noted, in their Third Assessment Report, that “It is now widely agreed that major loss of grounded ice and accelerated sea level rise [from the West Antarctic Ice Sheet] are very unlikely during the 21st century.” (East Antarctica is the coldest place on earth, and its ice hasn’t melted in millions of years.)Alarmists like Al Gore say increases in atmospheric CO2 will, through what MIT climatologist Richard Lindzen calls “implausible chains of inference,” cause huge increases in the rate of sea level rise. But the science tells a different story.Human CO2 emissions have been increasing atmospheric CO2 levels substantially since about the 1940s. So how much has rate of sea level rise increased in response?None.We have an excellent, nearly-continuous records of sea level from tide gauges at many locations around the world, some going back more than 150 years. Most show either no trend or decreasing rates of sea level rise in response to human CO2 emissions. The best and most comprehensive analyses of sea level measured by tide gauges around the world show slight decelerations in the rate of sea level rise over the last 80 years. Do you see any acceleration in sea level rise in this graph?
http://tidesandcurrents.noaa.gov/sltrends/sltrends_global_station.shtml?stnid=120-022We also have 19 years of satellite altimeter measurements of sea level over the open ocean. They also show decreasing rates of sea level rise:
http://www.aviso.oceanobs.com/fileadmin/images/news/indic/msl/MSL_Serie_ALL_Global_IB_RWT_NoGIA_Adjust.png
(Note that ENVISAT is measuring only about 1 mm/year of sea level rise over the last 8 years, compared to a rate of more than 3 mm/year measured by Topex/Poseidon over its 1993-2005 mission life.)Alarmists can cite anecdotes about rivers of meltwater, and skeptics can cite anecdotes about dramatic ice buildup (google “Glacier Girl”), but if you want to know what’s really happening with sea level, you’ve got to look at the measurements.

The measurements all agree: the last two-thirds century of human CO2 emissions have resulted in no increase at all in the rate of sea level rise. It’s irrational and unscientific to expect that the next two-thirds century will be different.
Dave BurtonCary, NC

By: Joshua Kerr

Joshua Kerr — Sat, 24 Dec 2011 13:34:00 +0000

Create an inland sea that floods the interior of Australia.

Use the inland sea as a safety valve capturing and releasing water depending on world climate conditions.

By: Paul Hosburgh

Paul Hosburgh — Thu, 08 Dec 2011 22:52:00 +0000

@Steve said “3.2 mm/yr, no sane person should lose any sleep over Dr. Wanless’s prediction”. There are plenty of sane people protecting themselves from different life risks a whole lot less severe than what he is saying. That is the Point of the drunk driving analogy. Also the rate of melt in the 1920′s-60′s was ~1.2mm. Should we have continued using those numbers because “any sane person” would not expect the rate of melt to be exponential. Sanity must also be Wise enough to understand math. The risk is real and increasing the hotter our air and water becomes as a result of CO2 pollution.

By: Steve Case

Steve Case — Thu, 08 Dec 2011 12:05:00 +0000

“…rapid pulses in the 20-foot range, and on a time scale that could be not centuries, but decades.”If you run the numbers on that, 20 feet is 6000 mm which means over the next 88 years to the end of the century sea level rise would have to proceed at a rate of nearly 70 mm/yr. Considering that the current rate is 3.2 mm/yr, no sane person should lose any sleep over Dr. Wanless’s prediction.

By: Mynuddin Uddin

Mynuddin Uddin — Wed, 07 Dec 2011 17:17:00 +0000

We have Mobile dialer. Master reseller L3.2.1 alaap visa citelink
emirate so any one contact with me …. Mynuddin53@yahoo.com

Mynuddin53@hotmail.com

Mynuddin99 :skype

By: Anonymous

Anonymous — Wed, 07 Dec 2011 01:33:00 +0000

Dr. Wanless is the guy that you want teaching your kids, because he follows the science to its logical conclusion. This takes some courage.

So, what are the logical conclusions, assuming that we can see evidence of sudden sea level rises in the past?