Tag: sea level

Going up

How much will sea level rise over this century? “Don’t know” is a good answer. “Not much” is looking like a bad answer that’s getting worse by the month. Last week a group of Northland Conservation Corps workers rode on a hikoi along Ninety Mile Beach to draw attention to the issue:

Tutor Mike Wikitera and his team erected five signs marking predicted sea level rises by 2030. The group, who rode horses to avoid adding to greenhouse gas emissions, erected the first sign at Shipwrecks Bay and placed the last one at Waipapakauri beach on October 30.

But what are the “likely levels” by 2030? The IPCC’s latest report projects between 18cm and 59cm by the end of the century, but only by excluding a very big unknown – how much ice will melt in Greenland and Antarctica. As more evidence of dramatic melt in Greenland arrives, it’s getting increasingly difficult to rule out multi metre rises. The latest number comes from Professor David Vaughan of the British Antarctic Survey, quoted in the Daily Telegraph [UK]:

Prof Vaughan says the main message is not to panic – the effects of melting will be gradual, in the order of three metres per century if the evidence of the past 20,000 years is anything to go by.

Three metres per century? That’s towards the top end of current speculation. 30cm every ten years, ten times the current rate, compares with 17cm over the last century. Prof Vaughan’s right about panic. It’s not a good option, but extreme concern is certainly justified. For some dramatic pictures of what might happen, check out this Greenpeace report on climate change impacts on Spain, timed to coincide with the IPCC meeting in Valencia to ratify the AR4 synthesis report. To see what 3m might mean for NZ, go here and zoom in on your favourite bit of beachfront property. NIWA’s current advice to local government is to allow for 50cm by 2100. That’s in need of considerable upward revision.

Meanwhile, the impact of sea level rise is not just high tides and wet feet. Salt water intrusion into fresh water coastal aquifers can be bad news for agriculture and drinking water – and the problem may be worse than previously thought, according a new study reported by Science Daily. The BBC covers one of the areas at most risk – Bangladesh – in a new series, documenting a boat journey through the country.

Revenge of the zombie facts

Dr Vincent Gray is one of the most active of NZ’s little band of cranks. He’s been publishing his “envirotruth” newsletter since the ’90s, always brimful of climate scepticism, and has been a stalwart reviewer of IPCC reports. His most recent contribution to the IPCC process was to make 1,898 comments on the final draft of the Working Group One report – 16% of the total, and, perhaps unsurprisingly, he accounted for 95% of the comments rejected by the authors. Vincent’s offerings are the backbone of the NZ Climate “Science” Coalition site, and I always enjoy reading them.

His most recent, Problems With Surface Temperature Data [PDF], is typical. He asserts it’s impossible to arrive at a meaningful figure global temperature, prefers satellite data but doesn’t believe it, and then states that “Since the amalgamated surface record is unreliable, an indication of temperature change over the past century can be obtained from well-maintained local records. Attempts to correct for the many errors, though not entirely successful, give records of some credibility.” (Otherwise known as the cherry-pickers charter). He then disinters a 1994 paper that found a 60-65 year cycle in global temperature (but I thought that was meaningless) if the data is “detrended”. One wonders what trend was removed. Perhaps the long term underlying rise in temperature? If we ignore the data, it goes away. Magical thinking at its finest.

[UPDATE 6/11/07: NASA’s excellent Earth Observatory posts a very interesting article about James Hansen and the development of the global temperature record. There’s a superb animation of atmospheric flows from space on page 2.]

But the most interesting part of Vincent’s report is the note at the end: “This paper is part of “The Science is not Settled: Major Issues Remain Unresolved by the IPCC: A Report of the NIPDD” (sic) (Non-governmental International Panel on Climate Change) to be published by the Science and Environmental Policy Project, Arlington Virginia.” The NIPCC? Seems this is something Fred Singer at SEPP has set up as a counterblast to the IPCC, and its report is due soon. From Fred’s The Week That Was for Sept 1st:

Highlights of the NIPCC Report

  • Demonstration of the insignificance of human contribution to current warming – using the ‘fingerprint’ method – and why future anthropogenic warming is negligible
  • Why climate models do not agree with observations – the role of feedbacks
  • Evidence that solar activity controls most climate change on a decadal time scale
  • Evidence that future warming will not accelerate sea level rise appreciably
  • No evidence for more storms, hurricanes, droughts, and floods as climate warms
  • How we know that a warmer climate is better than a colder one
  • Evidence that the Medieval Period was warmer than today
  • Evidence that pre-1940 warming was not anthropogenic
  • Problems with data quality and special problems with sea surface temperatures
  • Uncertainties about the CO2 budget, past and future – and of future emission scenarios
  • Changes in ocean heat storage, glacier length, and sea ice coverage indicate climate change – but not whether the cause is anthropogenic or natural

That’s a mind-boggling list. If all the papers show the – how shall I put it politely – “rigorous” approach to the science that Dr Gray demonstrates, the NIPCC report will be a real paradigm shift. Or perhaps not.

Time to buy new wellies

WellieRegular readers will know that I’ve been keeping a close eye on this year’s Arctic summer, and the record minimum sea ice extent reached last month (nice NASA picture here). The ice area is increasing now, but is still about 1m km2 below the same time last year. I might have to increase my bet… If all the summer Arctic sea ice disappears quickly, it won’t have any impact on sea level, but if the ice on land – mountain glaciers and the great ice sheets of Greenland and the Antarctic – melts, sea level will rise. During the last interglacial, about 125,000 years ago, global temperature was a degree or two warmer than today and sea level was about 5m higher. Some of that extra water came from Greenland and Antarctica.

When I was writing Hot Topic, the latest information suggested that Greenland was losing about 200 km3 (cubic kilometres) of ice every year, and Antarctica about 150 km3 (HT, p45). But time goes on, and the world warms. A study to be published in Geophysical Research Letters suggests that the glaciers of southeast Greenland are now losing 300 km3 of ice per year, a 400% increase in melt rate since 2004. AFP reports:

“Until 2004, the glacier mass in the southeastern part of the island lost about 50 to 100 cubic kilometres (12 to 24 cubic miles) per year. After this date, the melting rate accelerated to 300 cubic kilometres per year. It’s a jump of 400 percent, which is very worrying,” National Space Center head researcher and project chief Abbas Khan told AFP. […] The measurements indicated that the mountains hugging glaciers in the southeastern part of Greenland rose four to five centimetres (1.5 to two inches) per year, and that the banks of the glaciers thinned 100 metres per year.

Continue reading “Time to buy new wellies”

Another Friday roundup

NzmapI’m a sucker for pretty computer graphics, especially if they’re didactic. Today’s discovery is a superb Flash animation of the sea level history of Australia and New Guinea, lovingly prepared by Monash University‘s new SahulTime project [ABC coverage here]. From the web site:

The concept of SahulTime is similar to GoogleEarth, except that SahulTime extends each of GoogleEarth’s paradigms through a further dimension in time. Satellite-style images change to reflect coastlines, the icons are time-aware, and even photographs can can be taken through a timewarp to view reconstructed ancient landscapes.

You drag a pointer back along a profile of how sea level has changed over the last 100,000 years, and watch how Australia’s coastline changes, merging with New Guinea. Fantastic. Can we have one for New Zealand, please?

Meanwhile…

  • Al Gore’s film An Inconvenient Truth has been passed by a UK High Court judge as fit to be seen by UK schoolchildren, but only with changes to the accompanying teacher’s notes to clarify nine scientific “errors”. News media are buzzing: a few samples – Herald, BBC, and Guardian (UK). The BBC’s environment correspondent provides some context, and Stoat (aka climate scientist and ice gambler William Connolley) looks at how serious the mistakes really are. The right wing roots of the court case are explained by Oil Change International, and one of the “expert” witnesses looks like it might have been the NZ CSC’s own Bob Carter. Not surprising then that former ACT MP Muriel Newman’s NZ Centre for Policy Research site is all over the issue – though she manages to find two extra bonus “errors” from somewhere. Read the judgement in full here. Real Climate’s original review supports the judge’s finding that AIT gets the basic science right.
  • New Scientist reports on a Canadian study that finds that to keep global temperature under the EU’s target of 2C above pre-industrial levels, cuts of 90% of emissions will be needed by 2050, much deeper than the 50% reductions already promised.
  • The new edition of popular computer game SimCity is to feature global warming, offering players high and low carbon energy options – sponsored by BP. A sign of the times….

Clearing the decks

A few quick links before I post on the government’s just announced energy strategy: cleaning out the tabs in my web browser…

  • Professor Graham Harris of the University of Tasmania addresses the issues I raised in my “ecological overdraft” post a few days ago, in Sleepwalking Into Danger – an article for ScienceAlert: “It is time to admit how little we know and face the risks of planetary degradation – this goes way beyond climate change. Biodiversity isn’t just birds, primates and whales; it is planetary function and resilience.”
  • The Royal Society For The Protection Of Birds is planning [Guardian, BBC] to allow the sea to reclaim 728 hectares of coastal land in the Essex marshes on Britain’s east coast to restore habitat for wildlife – and as a pragmatic adaptation to rising sea levels. Could we see the same sort of thing here?
  • The Andrill project – a sea floor drilling effort under the Ross Ice Shelf involving NZ and US scientists – is using nifty Apple computers, so Apple has posted an interesting perspective on the work being done. New drilling season starts soon.
  • Brian Fallow in the Herald takes a look at the cost of carbon in the new ETS and speculates about ongoing impacts on the government’s accounts.
  • Carbon emissions from shipping may be much higher than previously thought, according to The Independent (UK).
  • German solar power company Conergy is planning a 500 turbine windfarm near Broken Hill in New South Wales. Meanwhile, BusinessWeek (US) profiles entrepreneur John O’Donnell, who has bought into Aussie scientist David Mills solar thermal designs, and plans to build a lot of generation at costs competitive with coal. With Silicon Valley money, and soon.
  • The Dominion Post digs up some advice to government on dealing with “environmental refugees”. NZ will probably want to help small Pacific nations, but refugees from the Asian megadeltas might be another matter.