Nasa recently announced likely 900cm rise in sea levels by 2100 based on work by Colorado University. News media uncritically broadcast this around world.
The Nasa press release is here
www.nasa.gov/press-release/nasa-science-zeros-in-on-ocean-rise-how-much-how-soon
It quotes Steve Nerem of the University of Colorado, Boulder, and lead of the Sea Level Change Team.
The front page of Sea Level team at Coloradu U (sealevel.colorado.edu/) has the following two graphs.
This shows sea levels as measured by satellites since 1993. The fact someone has fitted a straight line to the graph shows they think the rate of sea level rise is constant, more or less.
You might think there is a bit of an uptick in the last few months, but the second graph makes it clear this is due to the current El Nino. The graph above shows sea levels above the trend line in 1998, a big El Nino year.
This page shows tide gauge measurements
sealevel.colorado.edu/content/tide-gauge-sea-level
Which I’ve copied below
Tide Gauge Estimates of Mean Sea Level Rise
Estimates of global sea level rise which were derived from tide gauge records are found in the table below. Most of the investigators reported that the estimated values were sensitive to the choice of record length and the tide gauges selected. This sensitivity coupled with different computational techniques and modeling would certainly explain some of the differences shown below.
|
Sea Level Rise (mm/yr) |
Error (mm/yr) | Data Used (years) | # of Tide Gauges | References |
| 2.8 | ±0.8 | 1993-2009 | ~200 | Church & White (2011) |
| 1.7 | ±0.2 | 1900-2009 | >38 since 1900 | Church & White (2011) |
| 1.9 | ±0.4 | 1961-2009 | >190 since 1960 | Church & White (2011) |
| 1.43 | ±0.14 | 1881-1980 | 152 | Barnett (1984) |
| 2.27 | ±0.23 | 1930-1980 | 152 | Barnett (1984) |
| 1.2 | ±0.3 | 1880-1982 | 130 | Gornitz and Lebedeff (1987) |
| 2.4 | ±0.9 | 1920-1970 | 40 | Peltier and Tushingham (1989) |
| 1.75 | ±0.13 | 1900-1979 | 84 | Trupin and Wahr (1990) |
| 1.7 | ±0.5 | N/A | N/A | Nakiboglu and Lambeck (1991) |
| 1.8 | ±0.1 | 1880-1980 | 21 | Douglas (1991) |
| 1.62 | ±0.38 | 1807-1988 | 213 | Unal and Ghil (1995) |
It is clear satellites are measuring a greater rate of sea level rise than tide gauges.
Two reasons for this are
- They are not measuring the same thing, tide gauges measure sea levels by land while satellites attempt to measure sea levels across the whole ocean.
- Satellites have only measured sea levels for the last 23 years or so. The 1991 Mount Pinatubo eruption depressed sea levels around the world for a year or two. The 1998 El Nino boosted sea levels around the world. So satellites caught the rebound from the Pinatubo depression and the 1998 El Nino which together gave a higher rate of sea level rise, but only for a short while.
Permanent Service for Mean Sea Levels holds data for tide gauges around the world.
I have used PSMSL data to analyse sea levels around UK
and around the world.
Whilst I mean be wrong my results from around UK agree closely with those published by Prof Philip Woodworth of Proudman of UK’s Proudman Oceanographic Lab.
The Past And The Future
A rise of 3.3mm/year for 23 years is 7.59cm, a bit less than 3½ inches.
And on the basis of this we are supposed to believe there will be 90cm (around 3 feet) rise by 2100 – in 85 years.
In other words the rate of sea level rise, which according to satellites has been roughly constant for 23 years at 3.3mm/year, is going to jump to more than 10 mm/year.
I started blogging in 2011 because UK Environment Agency wanted to knock down a sea wall about 1/2 mile from my house. Their ‘logic’ was
- the rate of sea level rise is going to increase exponentially
- this means it will be too expensive to maintain sea defenses
- so the best thing to do is knock them down now
This graph has been on front page of JeremyShiers.com since 2011. It shows
- data PSMSL hold for Felixstowe,
- the trendline,
- and the claimed future rate of sea level rise.
David Middleton, writing at WattsUpWithThat.com, has a lengthier and more sophisticated analysis of Nasa’s false claims from which I’ve shamelessly copied the following 2 graphs.
This is similar to the graph of sea levels at Felixstowe – do you believe the projections?
The claim is sea levels will raise at over 10mm/year for next 85 years.
Sea levels did rise at about this rate after the last ice age, but nothing like it for the last 6000 years.
Measurement Errors
Any measurement will have an error, or uncertainty.
What are the errors for satellite sea level measurements?
In 2013 Tony Heller aka Steven Goddard published the following 2 images in a post titled
Shock News Satellite Sea Level Error Is 100% Of The Trend.
Both images came from Colorado University.
Whilst the link for sea levels still works (sealevel.colorado.edu/content/map-sea-level-trends). The link for measurement error does not. I wonder why. (http://sealevel.colorado.edu/files/current/sl_err_sm.jpg)
Government Bodies Wouldn’t Release False Information?
We’ve been here before.
In April 2012 the Envisat, the European satellite measuring sea levels, was shut down.
It had been showing rates of sea level rise much lower than other satellites. Within a day or two Envisat records had been adjusted to bring them into line with other satellites.
By chance I had saved Envisat data just before the records were changed so I was able to do a comparison Sea Levels Still Rising And Envisat Records Altered To Show This/
Amusingly who ever made the changes bungled. In making Envisat agree with other satellites overall they destroyed the existing agreement during the overlapping periods when 2 or more satellites had been operational.
Why Are They Doing This
The short answer is I don’t know.
There is a big climate change conference scheduled for later in 2015 in Paris.
It seems we are likely to see an increasing number of wild claims prior to this in order to justify whatever action is deemed necessary despite what actual data says.
As a lie repeated often enough becomes the truth.
Media Uncritically Repeats False Claims
On Friday 28 August around 19:45 in UK Sky news featured the Nasa report.
For around 5 minutes they uncritically interviewed a single expert who was allowed to make what ever claims he felt like unchallenged.
Why?
Normally 2 people with opposing views are lined up so each can say the other is wrong – and no conclusion is reached.
There was a time when reporters actually investigated themselves finding the facts to justify their stories.
I guess alarm sells and ‘everything is all right’ doesn’t.
