Renowden hatchet job fail
Gareth Renowden, of Hot Topic, has produced a shabby critique of an NBR article by Willem de Lange and Bryan Leyland. I use the word “critique” out of politeness, for it’s merely an ill-mannered hatchet job.
The NBR article, Evidence doesn’t support rapid future sea level rise, was published on June 10.
In his blog post, Gareth expects us to believe the excellent Willem de Lange is “slapdash” and that both he and our friend Bryan Leyland have “a long history of climate denial.”
However, Bryan is a respected consulting engineer with years of experience in designing and installing medium-sized power stations, including hydro, wind and solar. Willem teaches earth sciences and climate change at Waikato University and supervises PhD students. That he might somehow deny the very subject that he and his students earnestly research is outrageous.
The truth is that Willem’s publishing record of over 160 papers and articles towers over Gareth’s achievements.
Regular readers know that Hot Topic posts are echoed in the Blogs section on the SciBlogs website. I tend to see SciBlogs as the fetid swamp down behind the Royal Society bike shed, the place climate scientists can smoke what they like, eat with their mouths open and scrawl rude words on the walls.
But they overlooked this post from Hot Topic—was it just too stupid? Gareth starts with: “the piece is riddled with errors and misrepresentations.” Watch as I point out his errors.
- GR: The “recent” paper on sea level rise de Lange and Leyland (dLL) reference in their first paragraph is from 2010! The latest Royal Society of NZ climate info was published last month, and is presumably what dLL meant to refer to.
FAIL 1. Leyland and de Lange (LdL) didn’t supply this link, the NBR inserted it during editing. Gareth couldn’t know this because, happy with his presumption, he made no inquiries. I asked about it, but what do I know — Gareth’s the journalist. Shallow job, Gareth.
- GR: The rise in sea level around NZ over the last 100 years was 17cm, not 14cm, according to the RSNZ (page 28 here).
FAIL 2. Sorry, Gareth, wrong century. Over the 20th century (100 years) SLR was about 14 cm. From 1915 to 2015 or thereabouts (100 years) SLR was about 17 cm. Sea level varies naturally, speeding up and slowing down on decadal scales, and was a little higher earlier this century, pushing the century rate up a bit.
- GR: dLL claim that climate models are “flawed”, and have failed to predict current temperatures. In fact current global temperatures are more or less bang in the middle of model projections.
FAIL 3. It would be strange indeed if the IPCC predictions published in 2007 and 2013 (AR4, AR5) were not reasonably accurate only 9 and 3 years later. But after 15, 20 and 25 years, it is certainly valid to test predictions from the first three IPCC Assessment Reports (else how much longer would you wait?). They over-estimate warming by 6.0, 3.8 and 4.5 times observed warming since January 2001. They fail. Incidentally, Gareth’s link doesn’t work. When corrected, it does indeed show a graph from AR5 in 2013 and, unsurprisingly, observations are within the lower range of model runs. Gareth clearly thinks readers are stupid and will accept that climate models work just fine.
- GR: In discussing tidal gauge measures of sea level rise they refer to a denialist web site, not the primary sources.
FAIL 4. A denialist web site, eh? They should be arrested! But “denialist” simply means their views differ from Gareth’s, and what of that? Since they make data available from NOAA and PSMSL, the very same “primary sources” Gareth himself cites, this is a ridiculous and petulant objection.
- GR: They reference a textbook on sea level rise, but neglect to point out that it was published 15 years ago.
FAIL 5. No, they don’t mention the publication date, but they do say it reports SLR “during the 20th century” which was 15 years ago. That’s all you need. This is no flaw.
- GR: dLL state that the current rate of sea level rise measured by satellite is 3.2 mm per year, with “indications of recent decline in the rate”. In fact it is 3.4mm per year, and shows no signs of any recent slowdown. If anything, there are hints of an acceleration in the underlying rate.
FAIL 6. Squabbling over differences less than the margin of error is pointless and it’s petty. If Gareth’s “hints of acceleration” refer to the CU Sea Level Research Group graph on the page he cites, he obviously hasn’t noticed that there’s no hint of acceleration for the last six months. Wrong on two counts.
- GR: dLL claim that satellite measures are “about twice the tide gauge rate”. They’re not. They’re in good agreement. From Trends and acceleration in global and regional sea levels since 1807, Jevrejeva et al, Global and Planetary Change, 2013 (pdf)
There is an excellent agreement between the linear trends from GSL12 [latest tide gauge data] and satellite altimetry sea level since 1993, with rates of 3.1 ± 0.6 mm/yr and of 3.2 ± 0.4 mm/yr respectively.
FAIL 7. This is an appalling attempt to pull the wool over our eyes. The rates that are apparently “in good agreement” obtained only between 1993 and 2009—just 16 years. The long-term tide gauge rates are similar to other studies: 1.9 ± 0.4 mm/yr during the 20th century and 1.8 ± 0.5 mm/yr since 1970. About half the rate of the altimeters. There’s no error.
- GR: The latest RSNZ projections are not “much more than anybody else” – they’re based on the IPCC’s AR5 and draw on the current literature. Larger projected future rises are widely used in planning overseas.
FAIL 8. LdL didn’t say “much more than anybody else”, just “more than anybody else.” Well, more than most. LdL describe NASA’s 2011 prediction and the MfE-NIWA effort, merely saying the RS predicts a greater rise than them, which is perfectly correct. There’s no mistake here.
- GR: dLL state: “All the observational evidence indicates that the sea level is likely to rise 0.1 to 0.2 m by 2100.” This appears to be nothing more than wishful thinking. The current SLR rate gives 30cm plus by end of the century as a minimum.
FAIL 9. Read #7. There’s no evidence that the current rate of rise (1.8 ± 0.5 mm/yr) will drastically increase. Well, unverified climate models predict it, but they are not any kind of evidence. In the absence of verified models, engineers have always applied historical averages to climate phenomena, from rainfall to temperature. With business as usual, SLR to 2100 will be about 15 cm. If Gareth disagrees, let him tell us when it will begin to accelerate.
- GR: There’s strong evidence of increased and increasing ice sheet mass loss in Greenland and Antarctica, which will add significantly to the amount of sea level rise by the end of the century. If we’re lucky, that might only be a metre. If we’re unlucky, it might be a great deal more.
FAIL 10. There’s no evidence of a big problem. There has been increased ice loss, perhaps, but recent amounts of ice loss have been infinitesimal and cause no concern. At recent rates of loss, Greenland’s ice will last many thousands of years. Gareth kindly cited a page that confirms this.
“The surface mass balance for September 2014 through September 2015 … was the third least negative since the beginning of the record in 1990; not since … 1991-1992 … and 1995-1996 … has so little ice been lost.” (emphasis added)
Mr Renowden fails to address the other points made by Willem and Bryan but ramps up the hyperbole against Willem. He asks: “Do Christchurch ratepayers really want to pay for advice from an “expert” who can’t get his facts right, and who is apparently happy to put his name to rubbish?”
As I’ve shown, Gareth himself makes numerous errors in this attempted character assassination. His slapdash efforts mean he has earned no right to malign an honest scientist.
Willem and Bryan have shown that the Royal Society’s claim that SLR could be up to a metre by 2100 does not stand up under investigation. First, there’s no sign of an increase in the long-term rate of rise. Second, the Royal Society’s forecast is based on unverified climate models that show no long-term skill. Third, there has been little significant temperature rise for about 20 years. These are facts.
Why has the Royal Society ignored the fact that around New Zealand the land is rising or falling at different rates? Why have they assigned a single value of sea level rise to the whole country? Why do they collude with scientist activists in tacking satellite data on to the end of tide gauge data to show sea level acceleration? They must know it’s like comparing apples with bananas.
It marks a serious time in the history of science, to discover public servants ignoring the processes of solid science. There’s only one thing that might require the abandonment of good science: the desire to obtain an unscientific result.
Let us not banish honest, reliable scientists like Willem de Lange only to later regret that we failed to heed his calm counsel and, instead, we listened to a mischief-maker like Gareth Renowden.