This letter appeared in the print edition of 9 June:

I can only assume David Pope (Times2, June 5, p1) and Jennie Goldie (Letters, June 5) have not caught up with the latest on climate change. The Geological Society of Australia, representing more than 2000 earth scientists, has decided not to proceed with a statement on climate change as there was no settled position.
Oh, and don’t believe the myth that 97 per cent of world scientists believe the world is warming dangerously. The most basic research reveals this figure is based on sloppy survey work at best and deliberate misinformation more generally. None of this proves anything, of course, but you would think people would at least pause and wonder why.

H. Ronald, Jerrabomberra, NSW

I responded with this:

H.Ronald (Letters, 9 June) claims that it’s a myth that 97% of climate scientists support the conclusion that global warming is real and serious, but does not cite any sources. This seems to be a reference to a recent piece by Richard Tol, widely circulated in the climate denial echo chamber, criticising the original 97% study. In a strange mixture of irony and predictability, Tol’s paper itself has been found to be deeply flawed; after further analysis of his claims it is clear that the 97% consensus is confirmed and perhaps even strengthened. See for a full dissection of all this.

Spin them records

This letter appeared in The Canberra Times edition of 5 January 2014:

We are being fed nonsense by global warming proponents (”Records add heat to climate debate”, online, January 4).

Canberra’s record hot day was January 18, 2013, with a record of 42 degrees at the airport. That weather station has been open only since September 19, 2008.

The previous airport weather station was used from 1939 to 2010. Its hottest day was February 1, 1968, with 42.2 degrees. Walgett did not break a record. Its hottest day on January 3, 2014, of 49.1 degrees was recorded at the weather station that has been open only since 1993. The previous station ran from 1878 to 1993, and recorded its hottest day on January 3, 1903, at 49.2 degrees.

And there is no mention the US recorded the lowest-ever temperature at minus 40 degrees in International Falls, Minnesota, a few days ago. That is on top of the more than 1200 cold records in the US four weeks ago.

Of course, hot days prove global warming and cold days are merely outliers of no relevance, as letter writers remind me.

Brian Hatch, Red Hill

I responded with this, published on 15 January:

Brian Hatch (Letters, January 5) tries to cry foul over record hot temperatures, citing some cold records in the US in recent weeks and making his usual implication that global warming is all a giant conspiracy.

Despite the cold snap, in the 30 days up to January 5, the US saw four times as many record high temperatures as record lows. Over the past decade, the US had more than twice as many record highs as record lows. The ratio has been steadily increasing since the 1970s.

In Australia, the ratio is now more like three to one. Let’s not forget that in the last year we’ve had our hottest year, hottest season, hottest month and hottest day ever recorded.

It’s about time the reality-deniers got a grip.

Matt Andrews, Aranda

Festival of foolishness

The letters page of The Canberra Times of Saturday 4 January 2014 was ripe with the stench of climate denial.

I replied with this:

What a fine festival of facepalmworthy foolishness on climate (Letters, 4 January). H. Ronald of Jerrabombera led the pack with a re-run of the well-worn myth that there has been a “pause” in warming. This was repeated by Stephen Jones of Bonython, with a confused side reference to another long-debunked myth on tropospheric temperature anomalies, before wheeling out another deniers’ favourite, the claim that climate models “cannot reproduce observed changes”. Both referred with approval to Maurice Newman’s ludicrous spray earlier in the week, as did Owen Reid of Dunlop, who weighed in with a one-liner on the “mythology” of global warming.

There is no pause in warming. Climate models are remarkably effective at their job. If you rely on the climate-denial blogosphere as your trusted source of information (in which case, more fool you), try reading for a glimpse of what’s really happening out there.

By all means, weigh in on the climate debate, but be aware that among people who have bothered to inform themselves to a basic level, the debate is about the most effective and efficient ways of dealing with climate change. That the current crisis in climate is real, human-caused and serious is very old news.

Matt Andrews

Taxing people for keeping warm

This appeared in The Canberra Times letters on 7 September 2013:

Jenny Goldie, president of Climate Action Monaro, has a crack at Tony Abbott over his climate policies (Letters, September 4). To support her claims she states Monday had a high of 25 degrees – 10 degrees above the average Canberra maximum for September.

Well, I can use statistics, too. It appears Ms Goldie has used stats from only the past few years for Canberra. Looking at the Bureau of Meteorology’s historical data for Queanbeyan, between 1909 and 1956 the mean average for September was 17.4 degrees. This is 1.2 degrees below our mean average for the past few years.

Having lived in Canberra for the past 24 years, I can reassure the Ms Goldie that Canberra enjoys a burst of mid-degree temperatures every September. I suggest she looks at a longer and broader collection of data as opposed to narrowly focusing on the past seven years. In September 1980, we hit 28 degrees. Fortunately, the sky is still above us.

Anyone who thinks the carbon tax is a great idea should research European carbon tax fraud. Billions of dollars are being ripped out of European communities for no tangible benefit.

I am not a sceptic and believe we, as humans, do have an impact on our environment. I simply think taxing people, particularly here in Canberra’s cold climate, for keeping warm is not smart thinking. I look forward to Sunday when, hopefully, commonsense will prevail once again.

C. Crimmins, Turner

I responded with this, which appeared in the 10 September print edition:

C. Crimmins (Letters, September 7) argues against a carbon price because “taxing people for keeping warm is not smart thinking”. I’m afraid I have to take issue with this. The whole point of a carbon price is not to stop people keeping warm, but to shift energy use towards better efficiency and lower-carbon types of energy production.

The speed of the changes we’re seeing now – in terms of CO2 increase, ocean acidification, and global temperature rise – is unprecedented in the entire history of the human race. Clearly many species and whole ecosystems will struggle to cope as these shifts really take hold in the coming decades, undermining human economies, increasing the intensity and frequency of fires and floods, and likely leading to much more conflict and social breakdown than we have now.

The World Health Organisation estimates we already have 150,000 deaths a year due to climate impacts, and a recent report by the Climate Vulnerable forum, commissioned by 20 governments, puts the figure at 400,000.

Economically, the point of a carbon price is to shift the economy forward to a lower carbon basis in an efficient way. As opposed to “Direct Action”, which attempts to reduce emissions at a cost of hundreds of dollars per tonne. Smart thinking.

Straws, going cheap, hardly clutched

This appeared in the Letters section of The Canberra Times on 25 February 2013:

After years of claims to the contrary, UN climate chief Rajendra Pachauri’s acknowledgment of 17 years with no warming and none predicted to come is welcome progress, but it leaves much of the climate story untold.

Most importantly, this steady temperature has occurred despite constantly rising CO2 levels and a complete lack of correlation between CO2 levels and temperature change throughout the 150 years to which Pachauri refers.

This and other evidence tells us that CO2 is but a small part of a big, complex climate picture including solar variations, ocean heat transfer, cloud density, volcanic action, etc., and, quite possibly, some unknowns. It also means that any changes humanity makes to CO2 levels have little or no effect on climate. Hundreds of billions of dollars have been wasted at the behest of alarmists such as Pachauri trying to stop something that was not happening.

Acknowledgment is not enough – he owes the world an apology.

Doug Hurst, Chapman

This was followed by this, on the following day:

A number of well-informed climate change sceptics have been saying for some time in The Canberra Times letters pages that, despite huge increases in carbon dioxide emissions, the world has not warmed for the past 16 years. These statements have been met with abuse and ridicule. Now that Rajendra Pachauri, head of the Intergovernmental Panel on Climate Change, has acknowledged a 17-year pause in global warming, perhaps these critics will pause and reflect on what is really happening to our climate.

While this revelation does not mean the planet is no longer in danger from global warming, it does show that statements claiming the science is settled should be treated with great caution. We sceptics have been disparaged as deniers, but it seems to me that the real deniers are the climate change zealots who, despite changes in observed data, refuse to believe anything that does not support their apocalyptic view of the future.

H. Ronald, Jerrabomberra, NSW

On the same day (26 Feb), this appeared:

Those who prefer to get their science from scientists, rather than Andrew Bolt, will already be well aware that it is Doug Hurst (Letters, February 25) who owes us all an apology, not Rajendra Pachauri.

For those who are genuinely confused, but still prefer evidence and reason to prejudice and patronage, there is a very useful temperature chart that can be viewed at

This chart show that the long-term temperature trend is rather like an escalator: a series of plateaus, such as we are currently experiencing, but each one higher than the last, so that the overall trend is consistently and increasingly upward.

For those wondering where all the heat energy from higher carbon dioxide concentrations has gone over the past 17 years, it’s worth noting the top 700 metres of the ocean had increased heat content from 3×1022 joules in 1997 to 10×1022 joules in 2010. As it has before, the global system will soon enough ”rebalance” that excess and average atmospheric temperatures will again rise. All that extra energy has to go somewhere.

Felix MacNeill, Dickson

These responses appeared on February 28:

I am disappointed to see comments from IPCC chief Dr Rajendra Pachauri misrepresented by Doug Hurst (Letters, February 25). Dr Pachauri’s recent comments highlighted a prolonged pause in global temperature increases, which is certainly different to saying that there has been no global warming in recent years, as claimed by Mr Hurst. While the upward trend in global temperatures has slowed since 1998, temperatures have remained at more than 0.5 degrees above the long-term average. The trend has slowed, but the warming signal is still well and truly there.

Dr Pachauri also continues to echo that there is strong evidence the global warming trend will continue into the future. During his recent address to the UN Climate Talks held in Doha, Qatar, in December 2012, Dr Pachauri confirmed: “Models project substantial warming in temperature extremes by the end of the 21st century. It is virtually certain that increases in the frequency and magnitude of warm daily temperature extremes and decreases in cold extremes will occur in the 21st century at the global scale.”

Comments on climate change are welcomed and constructive to the debate about the best approach to solving the issue. However, the misrepresentation of facts and science is irresponsible, and prevents the wider public from engaging properly in the conversation.

Michael Mazengarb, Monash

Doug Hurst (Letters, February 25) says there is “a complete lack of correlation between CO2 levels and temperature change over the last 150 years”. In fact, over the past hundred years, CO2 levels have risen steadily from near-natural levels while average global surface temperature has risen by about 0.8 degrees Celsius, making nonsense of Hurst’s assertion. Moreover, deviations over that century from a constant linear relationship have been shown to be due to temporary phenomena such as aerosol pollution, solar cycles and volcanoes, with the underlying relationship of increased anthropogenic greenhouse gases and temperature being clear.

Hurst’s assertion, that any changes humanity makes to CO2 levels have little or no effect on climate, is not a scientific statement unless he backs it up by reference to research proving it so; at present it stands as a faith-based statement. While climate is complex, the overwhelming evidence so far is that there is a significant risk for humans (though not a certainty) from increased greenhouse gas levels in the atmosphere. We would be crazy to ignore this risk just because there’s more to learn.

Paul Pollard, O’Connor

I wrote this, which appeared in The Canberra Times on Tuesday 5 March 2013:

Self-labelled climate “sceptics” such as H. Ronald (Letters, 26 Feb) and Doug Hurst (Letters, 25 Feb) are quick to trumpet a recent report in The Australian by Graham Lloyd which claimed that UN climate head Rajenda Pachauri had said that there had been a pause in global warming for the last 17 years.

They should know better than to trust The Australian’s reporting on climate science. An investigation by the Skeptical Science website ( has revealed that Lloyd’s article misrepresents Pachauri’s views.

Hardly surprising, given News Limited’s long track record of supporting climate denial and inaction on global warming. In fact, Graeme Lloyd was caught out just last month misrepresenting a scientific paper on sea level rise (

A little more genuine scepticism would go a long way.

Matt Andrews, Aranda

This letter appeared on 7 March:

I watched the Leigh Sales interview of Professor Tim Flannery on the ABC last night, which presumably was meant to tease out Flannery’s recent claims that the extreme weather we have been experiencing is the result of climate change. It’s telling how soft Sales is with fellow travellers compared with for example, her somewhat excitable demolition of Tony Abbott last year.

Flannery has a well-known propensity to exaggerate, and his form in making dud predictions is legend, which qualifies him to be grilled mercilessly by Sales. Instead the interview was remarkable in what it left out.

While Sales did lamely mention the IPCC’s acknowledgement that the Earth has not warmed for some time, surely a first for the ABC, the obvious question she failed to ask Flannery was “You have made predictions that failed to materialise, most notable that a number of Australian cities would by now have run out of water, why should we believe you now?”

H. Ronald, Jerrabomberra, NSW

This then appeared in The Canberra Times on Friday 8 March 2013:

In his attack on climate change sceptics, including me, Matt Andrews (Letters, March 5) implies that sceptics are somehow misbehaving by using facts-based arguments. How silly of me. All along I thought the climate issue was about facts. And that the UN IPCC chief’s recent statement that we have not warmed for 17 years, with no warming forecast, is a most important fact – especially as it confirms very similar data from the UK Met Office (national weather service) just before Christmas. So too is the fact that this “pause”, as the alarmists call it, has happened despite constantly rising CO2 levels.

The basic alarmist case is that we face “dangerous and unprecedented warming”. Obviously, nothing dangerous is happening – other than in alarmist computer models, that is. As for the unprecedented claim, that too is wrong.

A report on March 4, 2013 from the Harvard-Smithsonian Centre of Astrophysics has concluded that “the 20th century is neither the warmest century nor the most extreme century in the last 1000 years” – that occurred during the Medieval Warm Period (800AD-1300 AD).

The alarmists’ forecasts have not been within a bull’s roar of reality, and I hereby declare victory for the sceptics. We have won on the strength of irrefutable facts. I don’t expect any apologies from the alarmists for their constant stream of abuse; a simple acknowledgment that the sceptics have been right all along will do.

Doug Hurst, Chapman

This appeared on Saturday 9 March. Peter Doherty is a Nobel Prize winner in the field of medicine.

Perhaps I’m missing something and Douglas Hurst (Letters, March 8) can enlighten me, but my understanding is that the medieval warm period was essentially a North Atlantic phenomenon. Even then, it was not as warm as what we’ve been experiencing recently and the general consensus among active climate scientists is that global mean temperatures were much cooler. On the other hand, both the United States and Australia have just endured their hottest summers since accurate record keeping began. Useful information on the climate, the extent of sea ice at the poles and so forth is available on the US National Oceanographic and Atmospheric Administration website. And maybe he could give us a better reference to the March 4, 2013 report from the Harvard-Smithsonian Center of Astrophysics that he cites. I would like to read it, but can’t find it, or any reference to it, online.

Peter C. Doherty
Microbiology and Immunology Department, University of Melbourne Medical School, Vic

This short comment appeared on 11 March:

Tim Flannery is 95 per cent correct. H. Ronald (Letters, March 7) is 95 per cent incorrect. It is therefore unsurprising that he should focus obsessively on the 5 per cent.

Felix MacNeill, Dickson

This letter also appeared on 11 March, from Professor Tony Eggleton, author of A Short Introduction to Climate Change:

Doug Hurst (Letters, February 25) and Felix MacNeill (Letters, February 26) both comment on the plateau in the trend of global warming. Hurst correctly points out that the global temperature is not simply controlled by carbon dioxide, but by many factors including the sun, ocean and volcanoes. MacNeill correctly points out that temperatures over the last 100 years have risen and plateaued and risen and plateaued. Neither explains why.

After World War II, resurgent industry fed all the products of burning fuel into the atmosphere, including carbon dioxide and sulfur dioxide. The latter converts to sulfuric acid droplets in the upper atmosphere which reflect the sun and cool the Earth. Greenhouse warming from the increased carbon dioxide was largely balanced by that cooling. After the Geneva Convention of 1979, industry cleaned up the sulfur dioxide in its smoke and the global temperature rose again – more quickly than it had pre-war.

Over the last 10 years, China has massively increased its consumption of coat, with little cleaning of the pollutants. Upper atmosphere sulfuric acid is back, the human induced sunshade is in operation, and this has partly balanced greenhouse warming from rising carbon dioxide (Kaufmann et al 2012, Proceedings of the National Academy of Sciences, China is committed to cleaning its coal smoke. The temperature plateau will end and there is a mountain ahead.

Tony Eggleton, Aranda

This appeared on 13 March:

Peter Doherty (Letters, March 9) is unlikely to get a response from Doug Hurst concerning the need for “a better reference to the March 4, 2013, report from the Harvard-Smithsonian Centre of Astrophysics”, so allow me to observe that Mr Hurst may have mistyped (or misread) “2013” when it should have been “2003”. The only relevant reference that I could find was to a paper by Drs Willie Soon and Sallie Baliunas, Proxy climatic and environmental changes of the past 1000 years in the journal Climate Research, vol. 23: 89-110, published in January 2003 ( A longer version was published in the journal Energy and Environment, Vol. 14, No. 2-3/ May 2003. The history of the controversy that this engendered is to be found at

The concluding sentence of the paper’s abstract reads: “Across the world, many records reveal that the 20th century is probably not the warmest nor a uniquely extreme climatic period of the last millenium” – which matches Mr Hurst’s claim fairly closely. Where he got the March 4 date from, I’ve no idea.

The Soon-Baliunas research was funded, directly and indirectly, by the American coal and petroleum industries (see the Wikipedia article for a summary).

Michael Saclier, Curtin

This appeared on 14 March:

Peter Doherty (Letters, March 9) wrongly dismisses the Medieval Warm Period as a North Atlantic phenomenon not as warm as today.

In reality, it was much more widespread and obviously a good deal warmer in places like Greenland, which really was green and supported farming of crops and cattle for generations until the Little Ice Age struck (for reasons unknown). Crops failed, cattle died, sea ice prevented fishing and the people perished. This and other evidence tells us that temperatures and change rates were both greater than at present.

As for the recent hot summers in Australia and North America, they are irrelevant.

It is the worldwide averages that count, and they have been stable for 17 years – helped, perhaps, by unusually cold northern winters.

Earth has been at least 10 degrees hotter and 5 degrees colder in the past and the tiny change of 0.74 degrees (International Planet Protection Convention figure) this past 150 years is quite unremarkable – unlike the total lack of correlation of rising CO2 and stable temperatures for 17 years, which is indeed something to remark on and ponder. CO2 is merely a bit player in a multi-faceted climate picture too complex to fully understand or control – unless, of course, you are Mother Nature and have been continually changing the climate without our help since the dawn of time.

Doug Hurst, Chapman

This short piece also appeared on 14 March:

Doug Hurst (Letters, March 8) quotes from a report said to be dated March 4, that “the 20th century is neither the warmest century nor the most extreme century in the last 1000 years”.

This quotation was actually from a paper published in March 2003 which has been thoroughly repudiated during the intervening 10 years.

The Medieval Warm Period was warmish in the lands around the north Atlantic, coolish in the southern hemisphere. Current global warming exceeds the (local) warming of the Medieval Warm Period both in magnitude and in rate of warming.

Tony Eggleton, Aranda

I responded with this (not yet published):

Doug Hurst (Letters, 8 March) calls for a fact-based discussion of climate, but then wheels out three laughably weak sources to support the notion that global warming has stopped.

He cites a News Limited report that IPCC chief Rajenda Pachauri had said that there had been a pause in warming for the past 17 years. This report has been disputed by the IPCC because it does not reflect Pachauri’s views. All the primary atmospheric temperature records – GISS (NASA), Hadley, the satellites, etc – show clear warming over this period. Even so, short-term peturbations in the atmospheric temperature are an almost trivial part of the big picture: the atmosphere receives only 2.3% of the heat accumulation due to global warming, whereas the oceans are absorbing 93.4% of the extra heat. The rest of the warming is of land and ice masses. Ocean heating, down to a depth of 2000 metres, is unequivocal – the data show very clear warming.

Hurst also mentions a report by the UK Met Office late last year as if it supported the idea that warming had stopped. This was a decadal prediction of global temperature over the coming years. It was widely trumpeted on climate denial websites as announcing a pause in warming, but in fact it predicted that warming would continue, and said that “we will see near-record levels of global temperatures in the next few years”.

Finally, Hurst appears to refer to a 2003 paper by Willie Soon and Sallie Baliunas, astrophysicists (not climate scientists), which purported to show that globally the Medieval Warm Period was warmer than the 20th century. The publication of this infamous paper, partly funded by an oil lobby group, led to overwhelming criticism of its dubious methods and data selection. Three of the journal’s editors resigned in protest at the paper’s publication. One of the scientists cited in the paper said that it was “so fundamentally misconceived and contains so many egregious errors that it would take weeks to list and explain them all.” It has well and truly been dismissed by mainstream science. There has since been a lot of comprehensive and soundly based work in the field, such as the publication in Science on 7 March this year of a temperature reconstruction by Marcott et al going back 11,000 years. It shows that the rate of warming over the last hundred years is utterly unprecedented over the entire period.

If this shambles of misattribution, misinterpretation and poor research is what passes for evidence in climate denial circles, it explains a lot.

Matt Andrews, Aranda.

Downplaying the climate issue

This letter appeared in the 1 Jan 2013 print edition of The Canberra Times:

The Coalition seems preoccupied with the government’s level of debt while dismissing climate change as a plot to destroy capitalism. I wonder if it would help to pen a call to arms in terms that would be understood by fiscal conservatives?

Earth has a greenhouse gas loan. Normally, if we repay any additional borrowings from the loan quickly, the bank won’t get upset. In the past, the bank has also not been troubled by our lack of repayments and the interest bill has looked manageable. However, we are now receiving nasty notices telling us that at our current rate of borrowing, we are on track to exceed a balance that will induce much higher interest rates (positive climate feedbacks). This will make paying down the debt that much harder, and perhaps impossible.

Instead of reducing this debt in earnest, Australia has agreed to slightly slow the rate at which it accrues debt. Meanwhile, we are getting off our heads on coal-seam gas, popping the tops off the new shale oil, and opening some of the world’s largest new coalmines, all supported by public subsidies to the fossil fuel industry. Party on!

We have a serious hydrocarbon spending problem and are creating a carbon debt that will take much more than the next generation to pay off.

It may well bankrupt us. Climate change is not a left-wing conspiracy. It is the bank calling.

Ben Elliston, Hawker.

This reply then appeared in the 2 Jan edition:

We all like to start the new year with a chuckle and the silly season obliged with the letters from Marian Saines and Ben Elliston (January 1).

[irrelevant para deleted]

Elliston tries vainly to resurrect the tired old subject of climate change – a debate being played out solely in The Canberra Times when the rest of the country, and the world, have long since moved on and are more interested in actual issues that affect our standard of living, such as the economic crisis and the fiscal cliff.

John Moulis, Pearce.

I replied with this, which appeared in the 5 Jan issue:

So John Moulis (Letters, 2 Jan) would have us believe that climate change is a dead issue that doesn’t affect our standard of living, claiming that the rest of the world has “moved on”.

While News Limited has continued its extraordinary campaign of climate denial (search online for “10 dumbest things Fox said about climate change in 2012” or “The Australian’s war on science“), and Alan Jones has been forced to take a fact-checking course after making a string of blatantly untrue claims on climate, the reality has become more and more clear and urgent.

Eighty per cent of Americans polled in December believe climate change will be a serious problem for the US unless action is taken. The science itself, on the basic questions of whether warming is happening and whether it is mainly caused by human activity, is now incontrovertible: there are mountains of evidence in support and literally zero credible lines of evidence against.

The recent Climate Vulnerability Monitor report, commissioned by 20 governments, found that climate change is already contributing to the deaths of nearly 400,000 people a year and costing the world more than $1.2 trillion, wiping 1.6 per cent annually from global GDP. And this just a very early stage of the impacts – things are projected to get much, much worse in the coming decades unless we stop fiddling around the edges and start taking this thing seriously.

Matt Andrews, Aranda.

Also in the 5 Jan issue was this pertinent comment on Ben Elliston’s original letter:

Thank you, Ben Elliston (Letters, January 1) for your brilliant analogy. It will enlighten some readers who have not yet engaged with the climate change issue. However, the analogy breaks down in the seriousness of failure. The financier who fails can declare bankruptcy and, nowadays, start afresh. If we fail to respond adequately to climate change and the problem escalates (positive feedbacks) beyond our ability to influence the outcome, we and our descendants risk the equivalent of life sentences in a Dickensian debtors prison. That’s why it’s vital to reduce greenhouse gas emissions much more quickly than we are yet contemplating. We already know how to do this.

But instead, state and federal governments are moving strongly in the opposite direction. Yielding to short-term and misguided commercial interests, they are supporting a huge expansion in coalmining and coal seam gas extraction.

David Teather, Reid.

Will humans survive climate disruption?

A recent question at Quora went like this:

Why wouldn’t humanity survive global warming?

Climate change is trumpeted as one of the most dire challenges to mankind. What is to say that, even if the globe changes irrevocably, humanity will not develop ways to survive in warmer climates? Are there challenges to our survival that we will not be able to innovate our way out of?

I answered with this:

There’s very little chance that humans will actually go extinct as any kind of short-to-medium term result of climate disruption. Humans are remarkably adaptable, and short of a scenario where Earth spirals into a Venus-style hothouse, surely humans will continue in some numbers, in some places.

However, we will definitely see many, many deaths. The World Health Organisation estimates we already have 150,000 deaths a year due to climate impacts (and a recent report by the Climate Vulnerable forum, commissioned by 20 governments, puts the figure at 400,000), and we’re still in the very early days of the curve of serious disruption. Later this century is not looking pretty at this stage.

To my mind the most serious climate threat to “humanity” as we know it is not extinction as such, but the breakdown of peaceful social structures. In the past we’ve had many local and regional conflicts over resources and land in times of stress, but these have always been specific to the pressures in a particular area. When we start having serious damage to food production, with more frequent extreme weather events and water supply disruption, we’ll start seeing conflicts over food, water and arable land in a more global and more intense way than ever before – if for no other reason than that the population pressure is so much greater now.

As a result it’s difficult for me to see a future – over the next 50-200 years – which does not involve far more warfare than the last couple of centuries, and probably the rule of the gun, without any effective national order, in some parts of the world.

Unless, miraculously, we start taking really significant steps to reduce the severity of the crisis, as opposed to the fiddling around the edges we’ve done so far.

You can see other answers and comments on this question at Quora.

Picking cherries from the melting ice

This contribution to a thread on The Canberra Times’ letters page appeared on Monday 29 October 2012:

Paul Pentony (Letters, October 25) trivialises the efforts of the St Roch voyages in the early 1940s. He commented on the various craft that have traversed the North West Passage (NWP) recently without mentioning that they had the benefit of satellite navigation, which simplified determining which route to follow. Also sail craft require much more open waters than motor craft as they must tack when the wind is against them.

One must remember that the St Roch was demonstrating Canadian sovereignty, letting the Inuit know that they were not forgotten during the war years and also supplying RCMP (Royal Canadian Mounted Police) outposts and that may account for some of the delay in traversing the NWP.

One must remember that Roald Amundsen sailed through the NWP in the early 1900s, also in a sailing craft without satellite aid.

The Norse expedition to investigate the extraordinary retreat of the sea ice in 1922 demonstrates beyond doubt that the amount of sea ice waxes and wanes and that the recent reduction of the sea ice is not all that unusual.

J. McKerral, Batemans Bay, NSW

In response, I wrote this, which appeared in the 2 Nov print edition:

So J. McKerral (Letters, 29 Sept) would have us believe that the collapse of Arctic sea ice cover is “not all that unusual”, because there was an expedition to investigate sea ice retreat in 1922.

This is a classic example of a tactic much favoured by climate deniers known as “cherry picking”: ignoring a huge body of evidence to focus on one tiny fragment that supports your stance.

In fact, there are hundreds of lines of evidence to show that the current loss of Arctic ice is unmatched in records going back thousands of years. See, for instance, “History of Sea Ice in the Arctic”, Polyak et al, Quaternary Science Reviews, July 2010.

Matt Andrews

“Modest” CO2

This letter appeared in the 18 September 2012 print edition of the Canberra Times:

David Teather (Letters, September 14) made some good points. His concerns are justified and, as an example, he pointed out the 39 per cent increase of CO2 concentration using a simple ratio based arithmetic calculation to arrive at a correct answer.

Another way of looking at this example is to use a simpler arithmetic calculation – subtraction. This provides us another correct answer of 110 parts per million, i.e. .011 per cent increase of CO2 concentration in our atmosphere since pre-industrial times.

Of course 39 per cent looks a more impressive headline figure than a very humble .011 per cent. Certainly it is a far more worthy number to bring grist to the alarmist climate mill.

John Morland, Curtin

… to which I replied …

So John Morland (Letters, 18 Sept) prefers to express the recent increase in CO2 as 110 parts per million, claiming that this shows it is “modest”, putting climate “alarmist” figures into perspective.

But what perspective? Morland implies that the current level of nearly 400 parts per million is safe, presumably because 0.04% just looks like a small number.

A better perspective is to relate this to the planet’s past. For at least 800,000 years, probably much more, CO2 has never been over 300ppm.

A huge amount of work has gone into projecting the possible impacts of higher CO2 levels. Many scientists suggest that 350ppm should be regarded as a safe upper limit. By the World Health Organisation’s measure, we’re seeing 150,000 deaths a year caused by the current level of climate disruption. At higher levels – 500, 700 and beyond – we face nightmare scenarios.

However, we have more than enough known coal, oil and gas reserves to take us well over 1000ppm if we continue with “business as usual”. Our current path does not just make catastrophe a possibility, it makes it the most likely result. We need to get off the fossil fuel train, and quickly.

Matt Andrews, Aranda

Reflecting on Arctic ice loss

John McKerral, one of the climate deniers who regularly adorn the Canberra Times letters page, has contributed a new dollop of facepalmworthiness. This appeared in the 5 September 2012 print edition:

Ice melt fantasy

Once again George Monbiot (“Wealth melts along with ice“, Forum, September 1, p7) has thrilled us with his fantasy scaremongering.

Monbiot wrote that as the Arctic ice melts, the sea, darker than the ice, will absorb sunlight that would have been reflected had the ice not melted. But sunlight arrives at an extreme angle to the surface that far north and is reflected back to space. Now here is some high school physics: light impinging upon water at a large enough angle (from the perpendicular to the surface) will not be absorbed, but will be reflected totally.

If the Earth was flat this would not happen as the angle of incidence, being less, would not result in it being reflected. However as most of us know, even sceptics, the Earth is a sphere and the angle that such light strikes the water that far north is such that it is reflected instead of absorbed. That whole article was based on a false premise and is therefore nonsense.

J. McKerral, Batemans Bay, NSW

… to which I replied:

According to J. McKerral (Letters, 5 Sept), “high school physics” says that sunlight shining on the Arctic ocean will be “reflected totally” because it arrives at a low angle, and so the extraordinarily rapid melting of Arctic sea ice is not a problem.

As a self-proclaimed “sceptic”, you would expect him to check this bizarre claim before proclaiming it to be true. And, of course, it’s completely false: while reflection naturally reduces the amount of radiation absorbed by water at low angles, it’s nowhere near zero in the Arctic Ocean in summer.

Fresnel equations show that with the sun 30 degrees above the horizon – typical for Arctic summer – water reflects less than 10% of incoming radiation, whereas sea ice reflects 30-70% of incoming radiation.

So the climate scientists saying that Arctic sea ice melt is a problem are right. Whoda thunk it?

It’s amazing that so-called climate sceptics – those intellectually dishonest traders in misinformation, distortion and outright falsehoods – have sunk so low in their desperate fight against reality.

What’s worse is that they continue to have sympathisers among many old white males in politics and the media. History will judge these people harshly long after they are gone.

Matt Andrews

Basically, McKerral’s foolish statements were wrong because they took a real effect (the increase in the albedo of water as the angle of the sun lowers) and utterly distorted it into falsehoods: that a low sun angle means radiation is “reflected totally”.

I used the figure of 30 degrees above the horizon as being a reasonable value for the Arctic in summer, because the Arctic Circle sees the sun at 47 degrees above the horizon in mid summer, and the North Pole at 23.5 degrees.

You might find this graph showing how the albedo of water changes with sun angle interesting; it’s referred to in the Wikipedia article on albedo (reflectivity). So when the sun is overhead the albedo is very low – only about 3%. When the sun is right on the horizon (at 90 degrees to normal) the albedo is nearly 100%. At 60 degrees from normal (30 degrees above the horizon) the average albedo is around 7%. Only when the sun drops below about 20 degrees do we see dramatic increases in albedo.