We know the current river gums (Eucalyptus elata) will go, loveable but thirsty trees. We also know the initially proposed scribbly gum was felled in favour of the brittle gum, which my sixth edition of Australian Native Plants states: "... tends to lose branches even on warm still days …"

In my view we need to not just reconsider the suitability of eucalypts, we should completely dismiss all eucalypt species from further consideration.

Despite their many beauties, they are a toxic, thirsty suppressive, invasive and incendiary genus. We need to ask ourselves whether we want an avenue of explosively flammable, limb-dropping, widow makers lining a major transportation network?

If we must go native, why not something like the impressive Grevillea robusta, described by Stirling Macoboy as "Australian flora's most outstanding and successful street and specimen tree".

And why must we have Australian natives? The majestic beauty of Canberra in autumn is a celebration of botanical splendour drawn from all corners of the globe.

I would like to see planted down Northbourne Avenue the Corylus colurna (aka the Turkish filbert). It is widely cultivated as an ornamental tree, very tolerant of difficult growing conditions in urban situations, and able to withstand air pollution.

Rohan Anderson, Turner

As for Northbourne Avenue becoming like a war zone for years during construction of the planned tramline, yes, exactly, only I believe Penleigh Boyd is partly mistaken in thinking the trees may eventually grow back in the median strip (Letters, January 25).

As has been pointed out, after the vegetation exclusion zone for new infrastructure is factored in, there would remain a 10 metre wide strip down either side that's suitable for trees. Recent artist's impressions of what the tramline may look like are more realistic.

The surrounds would probably consist largely of cement, and trees would have to be limited to middle sized, carefully tamed shapes (maximum 10 metre spreads).

Trees absorb and lock away carbon dioxide in the wood, and produce oxygen. A single large mature leafy tree produces enough oxygen to support two to 10 people a year. All leafy plants have also been shown to absorb the air pollutants found in cities (particulate matter, aerosols, volatile organic compounds).

A light rail corridor down the Northbourne Avenue median strip would certainly mean goodbye forever to the peaceful, wide, shade-giving (up to 10 degrees cooler), CO2 absorbing, O2 producing, air pollutant removing, leafy green oasis complete with forest giants, that it is at present.

A. Curtis, Florey

On Tuesday, Prime Minister Turnbull spoke meaningfully and well as usual about changing attitudes to violence and discrimination against women. However he failed badly when asked one last question by a journalist, that being, "What will your government do about the pay and superannuation gap women face"? He awkwardly spent about two minutes reiterating what he just said about violence and discrimination generally, but offered nothing in reply to the pay and super question. An answer would be nice.

Richard Roberts, Farrer

Please provide a list in your newspaper of all the supposed occupations in which a woman, undertaking the same work and doing the same hours, is paid less than a man. Too hard? How about just one? No? The truth is that this whole notion of women earning less than men is a statistical pea-and-thimble trick by the misandrists and politically correct. Does the public service have separate pay rates? Was Julia paid less than Kevin?

I'm sure any decent statistician (of either gender) could produce numbers that would show that women earn twice as much as men, or that gerbils are paid more than ferrets. Anything you like. I suspect that most of those doing the complaining are being paid far more than I am, and probably won't be happy until men are forced to work unpaid.

T. Leslie, Curtin

The story "World economic disorder needs new thinking" (Times2, January 26, p5) is timely, however politicians aren't listening and expect they can wait until the economy picks up and the deficits will be offset by surpluses.

This isn't going to happen because the world has changed. We have to update our mindset and be willing to pay for the services we expect the government to provide for us. We have a treasurer talking about lowering personal income tax rates and other ministers also peddling advice they think taxpayers want to hear and multi-national companies thinking that Australia is the Promised Land because they can operate in a very stable environment and pay no, or very little tax.

Many Australians receive transfer payments from the government and have earned them and other recipients have been let down by the system but someone has to bite the bullet and somehow balance the ledger. I don't believe Mr Turnbull would be game to do this because of the reaction by some of the dead-wood on his backbench and some easily-identified frontbenchers he has been lumbered with.

Mr Turnbull should "crash through or crash" Whitlam-like, and who knows, it could make him.

Les Brennan, Sunshine Bay, NSW

Slavery means slave owners have total power to mistreat their captives. Mandatory detention of asylum seekers (by the Australian government) means the government has total power but asylum seekers have none.

This means that Australia is a totalitarian state that employs thugs who can bash, even murder, captives in prison camps and get away with it.

We're on the same path (into the heart of darkness) as Hitler and Stalin.

On refugee policy, Malcolm Turnbull is Tony Abbott with a vocabulary.

Graham Macafee, Latham

I strongly support the Liberals' plan to make Canberra a trial site for self-driving cars ("Self-driving cars could navigate city's streets", January 25, p3). However, this will need a dramatic change to the current policy on repainting the white lines on our roads. Currently they are not repainted until after they disappear. This won't work for self-driving cars because they rely on seeing these lines, even in wet weather. More frequent repainting will be a welcome road safety improvement and a good use for the billions the Liberals will save by abandoning the light rail fiasco.

Chris Emery, Reid

A denizen of the Mesozoic Era, where climate change was "crap" and "coal was good for humanity", and essential to move millions out of "energy poverty", Abbott will be comforted by fellow troglodytes Alan Sears and Rupert Murdoch, who will emerge briefly from their caves to support their regressive crusade ("Abbott goes in to bat for US religious right," January 26, p4).

It does appear that Australian of the year, David Morrision, will be facing an impregnable wall of resistance – much more formidable than ever encountered in battle – to his gender equity efforts with Abbott remaining in public life. With Abbott on the loose, Islamic State has competition for the headlines. The Prime Minister must surely be quietly muttering: "Who will rid me of this troublesome [nearly was] priest".

Albert M. White, Queanbeyan

We are continually being reminded about yet another "warmest year on record", yet expansion of aviation, in this case Canberra Airport's international venture, is once more presented by "very frequent flyer" Ross Goddard as an unmitigated good (Letters, January 26). While he may be excited about "a massive market of holidaymakers and business people", the "growth forever" model of aviation has serious implications for climate change in terms of the continuing growth in greenhouse gas emissions from this industry.

Having studied the issue in depth, it seems even those who are environmentally well informed are reluctant or unwilling to forgo international air travel for tourism purposes. An important litmus test for climate change action will be when people actually change their behaviour, with the avoidance of international air travel being one of the best single steps an individual can take to curb further global warming.

Murray May, Cook

Two letters in The Canberra Times (January 27), one from H. Ronald and the other from Father Robert Willson, show there has been no real advancement in our treatment of the Aboriginal people.

Why must we dwell on the past? I know of no one who has argued that our past treatment of the Aboriginal people was not abysmal.

But all I hear is the need for an apology from one group, and from the other, the amount of money we have exhausted in endeavouring to improve Aboriginal life-styles. If an apology would make them happy, why not give them one?

Regarding the money spent, I still see photographs of Aboriginal women, with their children, sitting in the dirt under the shade of a tree. Perhaps we should move into the present and really improve the lifestyle of our most deprived citizens.

C. J. Johnston, Duffy

LEADER OF REPUBLIC

Australians are, of course, entitled to argue for a republic but they are in error when they claim this will give us an Australian head of state. We already have an Australian head of state in the governor-general.

David Smith, Mawson

THE HONEST TRUTH

I watched the gambling advertisements that preceded the tennis broadcasts recently and had to smile when at the end of each advertisement the advice to gamble responsibly was delivered. I would have thought that if one was being completely honest, the two concepts are mutually exclusive?

D. Perry, Amaroo

PLAY IT SAFE

Why don't they just keep footballers in rehab between games?

Charles Hirst, Latham

COST OF LABOUR

T.J. Farquahar (Letters, January 28) tells how much a railway line between Vientiane and the Chinese border will cost compared to the cost of the light rail line in Canberra. I wonder if the writer could give us a quick estimate of the cost of labour on each?

Roger Terry, Kingston

RETURN JOURNEY

Tony Abbott: a Comeback Kid?

Annie Lang, Kambah

CLIMATE OF INTOLERANCE

Rosemary Walters suggests the suspension of government services until politicians undergo climate re-education (Letters, January 27.) She might feel more comfortable if she moved to Cuba or North Korea. It's just a suggestion, Rosemary,

since it appears you're intolerant of scientific opinions that deviate from your views.

Gerry Murphy, Braddon

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