For the information of Mr Wilson and other like-minded people, gaseous emissions from Anak Krakatau consist largely of water vapour (because much of the volcano is submerged), plus some sulfur dioxide.

Sulfur dioxide is a much less potent greenhouse gas than carbon dioxide, methane, nitrous oxide and water vapour because it reacts with the water vapour to form minute droplets of sulfuric acid, which reflect sunlight back into space.

This reaction will be quite rapid in the case of Anak Krakatau because the water vapour is abundant and hot.

The water vapour does not remain in the atmosphere in the longer term, as do carbon dioxide and methane, and soon falls as rain, removing the last of Anak Krakatau's greenhouse gas emissions.

Mr Wilson's argument does not hold water.

Dr Douglas Mackenzie, Deakin

I was one of the lucky teachers who worked a double load in 1975, teaching full-time in a six-year high school while writing the curriculum for the new Secondary College system, opening in 1976.

I have met people in Canberra recently who do not know that we made our determined bid to have our schools run by us, long before self-government, instead of being outsourced to the Sydney-centric NSW Department.

I very much appreciate the article by Roberta McRae — "ACT's school system can handle Gonski 2.0" (December 19, p17) because she shows how far ahead of the rest of Australia we were then, and still are. In setting up the ACT Schools Authority, staffed by seconded teachers, under the imaginative and intellectually rigorous direction of Hedley Beare, we were able to search the world for best practice.

As McRae has written: "Policy and practices underpinning our system are future-focused and prize flexibility, adaptability, collaboration and [to use a Malcolm Turnbull-exciting motto] agility."

I feel proud to have spent the last two-thirds of my teaching career in the ACT school system and look forward to "Gonski 2.0's discussion on educational directions [which] affirms the vision" we pioneers had.

Frank McKone, Holt

The report "Green light for Anzac Park East building demolition" (canberratimes.com.au, December 26) contained one predictable announcement, "The developer has also been granted permission to rip up the site's trees and car park".

We can expect that what remains of the oak plantation between APE and the spooks' haunted house is doomed.

There was a good giggle in the closing words, "The developer is required to lodge separate plans for its proposed housing and commercial complex, which will be subject to further round of public consultation."

Public consultation? That's a standard punchline in the ACT. In this case the cynical snorts of derision are enhanced by the fact that the developer bought it last year "from the federal government for $34.3 million."

The site, being in the parliamentary triangle falls under the purview of the National Capital Authority. That makes any involvement by our town council in the exercise no more than a moot point as the pseudo-democracy foisted upon us by the federal government once again rubber-stamps another theft from ACT residents of their standards of living, yet another sale of their treasured environs.

G. Wilson, Macgregor

The Canberra Times editorial of December 4 is entitled 'Going green comes at a cost' .

Of course saving the planet from the impacts of climate change and other human interventions comes at a cost. But if people are happy enough to pay for eating out, travel, shopping for the latest gadget etc surely they will pay for saving the planet for their children and grandchildren?

Or are they? — I sometimes wonder with the media and politicians' fixation on energy costs that it is the only thing they think people care about — some hip pocket thing to the detriment of the obvious benefits of keeping temperature rise below 1.5degrees.

Sure, as the editorial points out, Canberrans are discriminated against because of the lack of co-ordinated national energy policy.

One solution — change the national government.

Also, as noted in the editorial, poorer people are impacted more by rising energy costs.

The solution – give these people financial support. The previous Labor government's carbon-trading scheme did this, but Tony Abbott abolished this program.

The Times editorial should have been entitled 'Going green comes at a cost but with long-term benefit'.

Rod Holesgrove, O'Connor

It should come as no surprise to anyone (other than to the gullible and the suborned) that agents of the Chinese Communist Party have long been brazenly – and criminally – stealing the most critical and sensitive of the intellectual, commercial and technological sweat and enterprise of others globally.

I have heard worthy commentators say this criminality does not constitute espionage.

In my view, it does. You simply cannot disentangle nowadays the commercial and technical from the political and the military.

Simply, the CCP is manoeuvring to be, sooner rather than later, the dominant hegemon. It is in a hurry, so all ethical gloves are off.

We grass eaters will be punished for our sloth.

To those former politicians and senior bureaucrats who have, in lucrative retirement, taken the 30 pieces of yuan, I say weigh carefully the value of the coin against whatever stock you put in your legacy.

A. Whiddett, Forrest

We read almost daily about the declining value of Australian and overseas equities. Superannuation is compulsory for workers in Australia – but how many realise their superannuation savings could be being eroded?

Many workers may be able to take remedial action to preserve superannuation savings by opting for less risky investment options.

When stormy weather approaches, the Bureau of Meteorology issues weather warnings.

The federal government gave us compulsory superannuation. Why not draw workers' attention to possible actions?

Richard Hogg, Curtin

Re: "Healing Farm's future in doubt", December 22, p8.

A review is being undertaken into the operation of the Bush Healing Farm just 12 months after it began operations.

The Bush Healing Farm, which cost more than $12 million to construct, is effectively unused, with the eight residences within the centre having been mothballed.

ACT Health is reported by The Canberra Times as claiming that it was never the intention that the Bush Healing Farm would operate as an Indigenous residential drug and alcohol rehabilitation facility.

That claim is incorrect. The Bush Healing Farm was agreed to and funded in 2007 when I was chief minister and minister for Indigenous affairs.

I was responsible for that decision. The Bush Healing Farm was intended, at the time it was agreed to fund its construction and operation, to be an Indigenous-specific residential drug and alcohol rehabilitation facility.

Jon Stanhope, Bruce

Beauty lies in the eye of the beholder, but it is hard to see anything magnificent in the London plane tree in Manuka to which Derek Wrigley (Letters, December 26) refers.

The tree is stuck down an alleyway with its trunk barely visible from the street and its crown draped over adjacent rooftops.

It presents a sad spectacle, out of scale with the other 28 trees that form a beautiful streetscape along this stretch. London planes are falling out of favour in other cities as their link with bronchial problems becomes more widely reported.

The hybrid imported species does not form part of the local ecosystem, and already exists in abundance around Canberra.

The case for deregistration of the tree is sound.

Karin Fisher, Griffith

M. Silex's defence of the refund of excess dividend imputation credits (Letters, December 23) fails to identify the main beneficiaries of current government policy.

They are wealthier households, and wealthier superannuants who pay no tax on their post-retirement super fund earnings.

Recent analysis by the Parliamentary Budget Office showed that in 2014-2015 more than 80 per cent of excess franking credits claimed by self-managed super funds went to funds with balances above $1million, and more than 50 per cent to funds with balances above $2.44 million.

Although 49 per cent of the individuals who claim excess franking credits have a taxable income under $19,000 a year, a fair proportion of these are likely to be wealthier than their low taxable income suggests. Australian Bureau of Statistics figures show that 85 per cent of shares are owned by households worth more than $1.3 million.

The Labor Party proposes to exempt certain categories of shareholders from its policy to cease the refund of excess imputation credits. Among these, M. Silex singles out trade unions, but in fact the exemptions extend to pensioners and part-pensioners.

These possibly represent most of the genuinely needy low-income individuals currently getting refunds.

Valid criticisms of the Labor Party's policy might well emerge, but they are not to be found in the partisan analysis offered by M. Silex.

Paul Feldman, Macquarie

When Julie Bishop was the (only) woman on the federal government frontbench she never uttered a word for women's causes. In fact, there was a noticeable silence. Nor did she work for the environment or take on the men in her party who shouted the cause for coal.

When she was unceremoniously dumped from the frontbench her reaction was to wear a pair of what she claimed were symbolic red shoes and then donate them to the Museum of Democracy, as if anyone could afford the shoes or care that she donated them. She was also seen greeting women MPs and making an ostentatious display of sitting next to them on the backbench.

Bishop has displayed the utmost hypocrisy about just about everything and now we read how she is going to jump off the back of Wild Oats X as she is "passionate about the health of the oceans".

At the next election perhaps she should jump off the back of the sinking Liberal Party boat.

E. Moffat, Weston

R. Baczynski (Letters, December 26) asks how much longer will relevant agencies ignore the potential for disaster, before banning all drones, particularly over densely populated areas.

Another example is the aircraft water bombing of a Christmas Day bushfire on Bruny Island in Tasmania, which had to be called off because of a drone flying in the area.

There are calls from the Civil Aviation Safety Authority (CASA) for those who got drones as Christmas presents to obey the rules, which include not flying drones higher than 120 metres above the ground, not flying within 30 metres of people, not flying at night, and not flying over or above people e.g. at festivals, sporting ovals, populated beaches, parks, busy roads and footpaths.

As with smartphone use while driving a vehicle, this is doomed to fail. Who will monitor it all? Is CASA hiring extra staff?

Murray May, Cook

I have the perfect solution for Donald Trump, who felt forced to close down his government because he was not given the funds to build the Mexico/American border wall.

All he need do is let out a tender to a reputable Mexican building/engineering firm to build it for him.

Obviously there would be American supervision, but a reputable company would have no trouble with that. Trump would no doubt save thousands (or millions) of dollars because of the cheaper labour costs.

It would probably be done sooner.

The Mexicans would be proud to have contributed to border peace.

The Americans would be relieved knowing it is happening without conflict.

And the American government shutdown would cease, meaning hundreds of Americans would be on wages again instead of being out of work. Everyone would be happy.

G. Barker, Flynn

PM'S INSENSITIVITY

When did the Prime Minister last go shopping on Christmas Eve with a long list, little money and worries about having to live from pay day to pay day with only uncertain work hours on offer from his employer ('Get shopping for Christmas': PM" , canberratimes.com.au, December 23)? Let's not forget that retailers aren't the only ones who may have had a "torrid year" and would love to experience a miraculous turn-around in their circumstances.

Sue Dyer, Downer

RERUNS RANKLE

In 2019 will the ABC change its name to the GDN (the "Grand Designs Network")?

T. Puckett, Ashgrove

SIGN OF BAD TIMES AHEAD

Dr Johnson famously wrote that "patriotism is the last refuge of the scoundrel".

What a tragedy he isn't alive today, to observe politically nosediving heads of state like Scott Morrison and Donald Trump make "spontaneous surprise visits" to war zones and be filmed backslapping the chaps in uniform.

He would revise his dictum to a less snappy but even more precise "war zone troops' meeting-and-greeting is the last recourse of a failed leader".

A. Mattea, Sydney, NSW

US NEEDS NELSON

I notice the US has not yet built a national memorial in Washington to commemorate their participation in World War I. Could I respectfully suggest that we send Brendan Nelson over to sort them out?

Maggie Watts, Calwell

THANK YOU TO NURSES

The nurse is the backbone of the health system. Imagine a hospital run without nurses, it would not happen. To all the nurses out there, I want you to know we admire you, and look up to you, you are a credit to humanity. Thank you for everything that you do.

Richard Ryan, Summerland Point, NSW

G-G CRITERIA

ScoMo mistook the intent of the hyphen in Governor-General. He thought 'Governor' and 'General' were prerequisites for the job. Hurley's appointment satisfies these criteria. Simples.

Peter Snowdon, Aranda

RIGHT CALL BY SCOMO

It's unfair to criticise Scott Morrison for not moving into The Lodge. He's simply acknowledging that by the time the removalists had finished unpacking and arranging the furniture, it would be time to pack up again.

Peter Dark, Queanbeyan, NSW

HIGH-RISE WOES

Can Andrew Barr state categorically the high-rise buildings springing up all around the ACT, particularly those in Gungahlin, will not be subject to the dangers experienced by residents in the Opal building in Sydney?

N. Bailey, Nicholls

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