By Guest Author 19/08/2016

By Dr George Preddey

Two contrasting colour illustrations on the back cover of the NZ Listener (July 2-8) are disquietingly reminiscent of contrasting sketches that appeared in a 1981 report on climate disaster by the Commission For the Future, 35 years ago.   

These illustrations and sketches feature the Beehive as in 1981 and 2016 and as inundated later this century by rising sea levels, now unequivocally attributed by climate scientists to climate disruption.


A conjecture that CO2 emissions from the burning of fossil fuels would cause climate disruption was published 120 years ago in 1896 by the Swedish physicist Arrhenius.   Unequivocal proof of Arrhenius’ conjecture has been provided by decades of peer-reviewed science consolidated in the fifth Assessment Report of the Intergovernmental Panel on Climate Change (AR5, 2013).

Limits to growth

A strong driver of climate disruption and sea level rise is neoliberal free market economics, in many respects an ideology rather than a science.   A truly “free market” is a myth since free trade in child labour or heroin would be unacceptable, even to economists, as should free trade in carbon.   The belief that the so-called “invisible hand” will optimally match supply and demand defies rational explanation.   There is compelling evidence that the so-called “trickle down” theory simply doesn’t work.   Indeed data recently released by Statistics New Zealand shows that the divide between the rich and the poor is growing faster in New Zealand than in any other developed country.   In 2016, some 305,000 New Zealand children are living in poverty, some in cars.

Another driver of climate disruption is outlined in the Limits to Growth (L2G) report published by the Club of Rome in 1972.  L2G describes a set of computer simulations of a future Earth.   Its business-as-usual (BAU) projection predicts overshoot and collapse of the global economy, environment, and human population from about 2020 onwards.  L2G’s central argument, rejected by most economists and politicians but self-evident to most scientists, is that growth within any closed system including the Earth’s closed biosphere is ultimately unsustainable and inevitably leads to overshoot and collapse.

L2G’s BAU projection has accurately tracked 40 years of subsequent statistical data collected by many international agencies, and accordingly should be taken very seriously.   So too should the warning of a preeminent scientist in 1954, at that time describing the existential threat posed by nuclear weapons that continues unabated today but equally applicable, in my view, to climate disruption and to overshoot and collapse from about 2020 onwards.

“We shall require a substantially new manner of thinking if mankind is to survive.”

(Professor Albert Einstein, 1954)

Another indicator of overshoot and collapse is the increasing global divide between the rich and the poor demonstrated by global increasing homelessness.   This divide is growing faster in New Zealand than in any other developed country.  In his book Capital in the Twenty-First Century, economist Thomas Piketty (2013) argues that the divide between the rich and the poor will continue to widen as long as political decision-makers continue to tax income rather than wealth.   According to Piketty’s reasoning, New Zealand should progressively shift from taxing income, especially of low wage workers, to taxing wealth, especially wealth derived from capital gains (currently tax-free).

Climate disruption is a compelling example of overshoot and collapse.  AR5 predicts emissions growth driven by population and economic growth (without “additional mitigating measures”) will result in a mean global temperature increase of 3.7 to  4.8 °C above pre-industrial levels by 2100, contravening the agreement among 195 nations at the 2015 Paris climate summit to limit global warming to 2°C without actually specifying any “additional mitigating measures”.  UK Met Office, NASA, and NOAA data all confirm 2015 as the hottest year on record since systematic reporting began in 1850; a new world record is likely to be set in 2016.

According to AR5 (2013), unabated emissions by 2100 will eventually cause a 2.3m sea-level rise per 1°C of mean global temperature increase.  However AR5 is not the whole story.  Radar soundings of Antarctic glaciers have revealed troughs under the ice sheet that when inevitably flooded by relatively warm sea water will trigger major ice sheet collapses sufficient to raise global sea level by at least 10m.  An improved ice sheet model in 2016 predicts major ice sheet collapse over the next few decades in response to currently predicted levels of global warming.   During the Pliocene era 4 million years ago when the planet was 2-3°C warmer than today, sea level was 20m higher, attributed largely to collapse of the Antarctic ice sheet.

The Royal Society of New Zealand recently hosted a screening of “Thirty Million”, a documentary film about the devastating consequences of sea level rise for the low-lying nation of Bangladesh over the next few decades.   “Thirty Million” is the number of climate refugees predicted to be displaced by sea level rise by 2050 from Bangladesh’s current population of 160 million.   About 200 million climate refugees globally are predicted to be displaced by 2050: hundreds of times greater than the current influx of refugees into Europe driven by drought and ongoing conflict.

“We have enough knowledge to act, but it is the collective acting that is required now

…If we are not careful then we will be definitely suicidal if not evil, a word attributable

to those who have the power to act and have not used it.”

(Dr Atiq Rahman, Executive Director of the Bangladesh Centre for Advanced Studies, 2016)

No one home

New Zealand’s current population (4.5 million) is 0.061 percent of the global population (7,400 million).  Its annual refugee quota of 750 was recently increased to 1,000.  In my view, the revised quota should be increased to at least 0.061 percent of 200 million over the next three decades: i.e. 5,000 annually, especially from low-lying Pacific Island nations. Even a five-fold increase does not fully compensate for New Zealand’s relatively large per capita contribution to climate disruption nor for its evil policy choices.

New Zealand’s response to climate disruption reflects poorly on the integrity of a Government that achieved pariah status including a “Fossil-of-the Day” award at the 2015 Paris climate summit.  Its commitment to an 11% reduction in carbon emissions by 2030 compared very unfavourably with the commitments of the European Union to a 40% reduction, the United States to 28%, and China to 20%.

Equally unacceptable, under current policy settings New Zealand’s net emissions are officially projected by the Ministry for the Environment to increase by 159% by 2030, not to reduce by 11% by 2030 as promised at Paris, nor to reduce by 50% by 2050 as promised by the “50-by-50” election slogan used shamelessly by National during its successful 2008 election campaign. The National Government to date has not been held accountable for this broken election promise.

Unsurprisingly, New Zealand’s climate protection policies ranked fourth worst among 60+ countries according to a reputable Climate Change Performance Index (2015) and its Emissions Trading Scheme (ETS) ranked 25th of 26 countries according to a World Bank review (2014).   Accordingly, New Zealand’s ETS should be scrapped entirely in my view and replaced by:

–   a carbon budget that emphasises essential outcomes determined by robust science rather than by shonky carbon pricing

inputs based on spurious and possibly fraudulent economics; and

–   an inescapable increasing carbon tax/charge applied at points of fossil carbon extraction, importation or emission and

remitted in full to the public to compensate them for increasing fossil energy power bills.

Increasing homelessness is one of the inevitable consequence of a rampant neoliberal free market economy in my view.  In Bangladesh the immediate driver is sea level rise.  In New Zealand the immediate driver is property investment, often by speculators who are manifestly increasing their wealth through huge, tax-free capital gains.  The solutions to increasing homelessness, both locally and globally, in my view are for political decision-makers including the National Government to:

–   consider whether neoliberal free market economics is a fundamentally flawed ideology that may have evil consequences;

–   consider Professor Einstein’s warning about the existential threat posed by nuclear weapons that, in my view, is also applicable to climate disruption, overshoot         and collapse, and increasing homelessness;

–   increase New Zealand’s annual refugee intake quota five-fold to at least 5,000 climate refugees annually;

–   accept Piketty’s rationale for taxing wealth rather than taxing income, and, having the power to act, use it;

–   enact appropriate tax regimes including a carbon tax/charge to address climate disruption and a capital gains tax to address increasing homelessness.

George Preddey is a former atmospheric physicist (DSIR), futurist (CFF), tertiary teacher (VUW), disaster manager (MoCD), chief adviser (MoE), and international tertiary education consultant (ADB, ILO, OECD, UNESCO, World Bank).

0 Responses to “Overshoot and collapse – climate disruption and increasing homelessness”

  • On behalf of my first grandchild, Hemi, thank you Dr George Preddy for the most relevant an elegant, precise and concise piece of science communication. I would like to see a copy distributed immediately into every single MP’s in-box with an invitation to return a comment on their response. And to every regional and local government mayor and councilor with the samer invitation. The response would add another set of evidence-based data for consideration by responsible grown-ups throughout the land. One area of current concern I would add to this statement is the broken neoliberal financial system. Evil is a scientific term for me as anything anti-life. James Howard Kunstler the New York up-state writer gives an equally precise and witty interview on the inconvenient reality including the financial and political spectres that are calling forth the best of times in the midst of the worst :

    • If we were discussing how current government policy is affecting NZ’s GDP then it would not make much sense to look just at the trend over the last 100 years (as done on that particular NOAA web page). In the case of sea level rise it is even clearer that the 100-year trend is not the issue given the amount of data showing accelerating rates of loss in ice sheets over the last 30 years. An up to date analysis of sea level data is available at: . This shows that when they use GPS data to correct for changes in tide gauge height, and then use that to calibrate satellite data and get global coverage, the rate is increasing. So while the average rate since 1992 is 2.9 mm/yr, for the last 10 years it has been ~4 mm/yr. This is close to the top end of the range that was given for this decade by the climate models used in the last IPCC Assessment Report. What it means for 2100 is still subject to debate, but we can’t ignore the paleoclimatic evidence showing that sea level responds to global average temperature and that it was about 20 m higher the last time the Earth was about 3C warmer. Hopefully the rate at which that happens is not completely unmanageable.

  • That sea level data is from satellites and has a lot of corrections. It isn’t matched by the sea levels as actually measured by tide gauges. Which is the correct measure?
    I also note the referenced paper in your link says: ” First, the GMSL rate (1993 to mid-2014) is systematically reduced to between +2.6 ± 0.4 mm yr−1 and +2.9 ± 0.4 mm yr−1, depending on the choice of VLM applied. These rates are in closer agreement with the rate derived from the sum of the observed contributions2, GMSL estimated from a comprehensive network of tide gauges with GPS-based VLM applied (updated from ref. 8) and reprocessed ERS-2/Envisat altimetry9. ”
    Now mid -2014 is only two years ago. That sounds fairly recent, certainly closer than ten years ago. And if sea level is rising at 4mm a year, why has the trend in Wellington 1998 onwards been flat? After all, that is where the Beehive is that is supposed to be flooded.

    • Don’t understand why you are just going to mid-2014. Did you see the link to the most recent data on that CSIRO web page?
      But more importantly why do you think that the satellite data disagrees with the tide gauges and why do you think the trend at Wellington is flat? Where are you getting your data from? I’ve done a comparison of the NZ data – see – with the satellite data for points around NZ – see At a regional scale there is much more interannual variability than in the global average and for NZ this is correlated with the ENSO that affects ocean heat distribution and so thermal expansion of sea water. It’s a pity I can’t put one of my graphs in here, but since 1993 the 10-year average rate of SLR around NZ, based on tide gauge data, has varied from about -3 to +11 mm/yr and this matches the satellite data very well. Then as Yi et al (Geophys. Res. Letts, 42, 3998-4006, 2015) pointed out the most recent data are no longer showing the same correlations with ENSO because that does not modulate the increasing rate of ice loss.

  • Martin
    Don’t you bother to even read your own links? if you did, you would see the Denys paper goves the RSL rise for Wellington as 2.09mm/yr – nowhere near your numbers. It is RSL that matters for flooding risk as another part of one of your links shows
    If you look at this much reproduced map of GMSL rises, you can see the Solomon Islands is in the centre of a hotspot where the sea level rise is supposed to have been about 10mm/yr. However, if we go to the RSL data we get this showing no sea level rise.
    Even Kiribati, the poster child of flooding risk, shows no significant sea level rise and definitely no acceleration
    Now what do we believe, the satellites or the tide gauges? Or do peer reviewed papers trump tidal gauges?

  • Why are my ten year average rates varying from minus three to plus eleven inconsistent with the Denys longer term average of plus 2.09?
    Have you read the papers cited on that CU sea level web site, or looked at the more recent work by Anny Cazenave showing evidence that ice loss has recently become the dominant cause and so we are dealing with some new issues?
    (see – under “sea level rise and ice sheets”)
    How are you extracting a trend of mm per year from the Solomon Is data which is shown as so variable on the BOM web site that they give the sea level there in meters?
    You may not like the satellite data but have you read John Hannah’s recent review of the issues for NZ tide gauge data done for the Parliamentary Commissioner for the Environment last year – see .
    Clearly this discussion is going nowhere.

  • Martin
    I do not see that there is much value in disputing whether the sea level rise is 2mm/year or 3mm year for Wellington. The data set is only 60 years long and the interannual variability means the start point can have a big influence on that. That is why I don’t see any value in ten year analyses.
    My comment about Kiribati was showing that the ENSO induced variability swamps any underlying signal. It wasn’t that long ago that a lot of noise was being made about how the islands were being drowned. Where are those commenters now?
    With regards satellite data, The Hawaii site comments ” The satellite trends reflect changes in the sea surface height only, with most of the spatial variation resulting from the influence of winds blowing over the ocean. ” If you look at the data, there are drops of up to 10mm occurring in the GMSL. You can understand it with tide gauges and the wind pushing the water to another part of the Pacific but the nett GMSL should be unchanged. The only way GMSL can decrease is either a lot of water goes into the atmosphere or ice caps, or the ocean temperature drops a lot. AR5 gives the size of various effects and none of the can account for a drop.
    The potential effects of adapting to sea level rise will cost billions of dollars – the current situation in ChCh is just a small example. For such sums, one would want total confidence that the models were correct. They aren’t. AR5 says about them “It is very likely that warming of the ocean has contributed 0.8 [0.5 to 1.1] mm yr–1 of sea level change since 8 1971, with the majority of the contribution coming from the upper 700 m. The model-mean rate of ocean thermal expansion for 1971–2010 is close to observations, but for 1993–2010, the model-mean rate exceeds that observed. ” Doesn’t exactly fill one with confidence.
    With regards the headlines, Mr Preddy’s article AR5 says sea level will rise 2.3m by 2100. AR5 actually says ” Using the same methods as for simulating past GMSL change (and including estimates of ice sheet dynamical contributions from the literature), it is virtually certain that the rate of global mean sea level rise during the 21st century will exceed the rate observed during the 20th century for all RCP scenarios (see Box 28 TS.4). For the period 2081 to 2100, compared to 1986 to 2005, global mean sea level rise is likely to be in the range 0.29–0.55 m for RCP2.6, 0.36–0.63 m for RCP4.5, 0.37–0.64 m for RCP6.0, and 0.48–0.82 m (0.56–0.96 m by 2100 with a rate of rise 8 to 15 mm yr–1over the last decade of the 21st century) for RCP8.5. ” That is a fair bit of difference, especially as RCP8.5 is unobtainable as there isn’t enough coal available to burn.
    The photo image implying what the sea level will be in 2100 is deliberately wrong even if it gets to 2.3m. After his misquotes he starts getting into politics and bringing in homelessness and free markets. That is advocacy, not science.

  • Clearly Mr Morris is indulging in his usual practice (and that of his cronies) of switching scales whenever it serves to suggest a contrary trend. We’ve seen the NZ denial camp doing it with global temperatures and now Mr Morris is having fun with NZ tide guages, hardly the gold standard in a maritime climate affected by the roaring 40s, ENSO effects and crustal movements, realities that even he concedes. If AGW is taking place then changes have to implemented sooner rather than later. That the change is happening is undeniable. There is no corresponding signal from the natural drivers of climate variability, the physics link it to changes in our atmosphere and chemistry shows it’s from burning fossil fuels. It’s Mr Morris who is playing politics. There is actually good science that shows profound economic inequality sacrifices social capital and human potential, assets no human population can afford to do without.

  • That humanity and civilisation has affected climate locally and regionally I gather is pretty well established, de-forestation in Egypt and South America. I suppose it was only a matter of time before global effects became noticeable. There has always been feedbacks between living things and climate, the effects of bacteria on our early atmosphere.

    What interests me is the psychological motivation of the educated quibblers and deniers. One noticeable characteristic is they seem to be retired, sometimes retired scientists, often with agricultural links in NZ, elsewhere mining and engineering. Another possible factor is habit. A lifetime of composing texts and crunching numbers. A final
    characteristic I suspect, is the “Stag at bay” syndrome. I noticed it today with old Cecil our ram, stamping his foot at Clancy the Irish Setter and even making head butting motions.
    So it may be our scientific friends, used to status and respect, or what passes for it in a government department, are determined to show there’s life in the old goat yet!

  • And you, Stuart, are still indulging in your usual practice of ad homs so that makes it about even, doesn’t it?