Immediate transfer to intensive care on suicide watch is indicated. Nothing less than a radical transformation of human thought and behaviour at the global level is required to combat the four deadly P's - Population, Poverty, Pollution and Preparation for War - and replace them by the four friendly E's - Enlightenment, Ecology, Education and Ethics.

The present unsustainable Anthropocene era must be supplanted by a sustainable epoch, converting our carbon economy to a photon economy, according to NASA physicist James Hansen. The planetary therapeutic team should be led by a re-invented United Nations, preferably with a female Secretary-General, well financed and empowered to keep order.

Climbing Mount Improbable was the title of Richard Dawkins' populist book on evolution. Unless humanity can collectively climb the improbable mountain of achieving sustainability, in harmony with each other and with the natural world, Cribb's worst prognosis may come to pass, and humans will have experienced the shortest civilisation in history.

Bryan Furnass, Hughes

There is one important observation not present in your assessment (''Adelaide Labor to hold on, for now'', March 24, p2) of yet another South Australian instance where the Liberal Party has a clear statewide, two-party-preferred majority but has failed to achieve government.

Although the winner-take-all nature of single-member electorates means that the House of Assembly's composition never resembles the underlying support bases of the major parties, the risk of an extra-constitutional outcome are heightened whenever, as in 1985 and 2006, the Liberals are virtually wiped out in the metropolitan area. In those circumstances, with nothing to win in regional and rural areas, a Labor government can concentrate on maximising the day-to-day advantages of incumbency in marginal metropolitan electorates in which their opponents have limited presence, none of it full-time.

The structural imbalances and minority-support outcomes will continue until electors' influence is increased and representative Assemblies are guaranteed through effective voting in multi-member electorates under the Hare-Clark system.

Bogey Musidlak, convener, Proportional Representation Society of Australia, (ACT Branch)

Can anything be done about the pathetic Canberra news service provided by ABC television at 7pm? For the second night in a row not one item about Canberra, weather excluded.

Every day, when I move around our city, I see stories. Yet none appear on ABC TV. If there does happen to be a local story it's usually pinched from The Canberra Times that morning or is a goody-goody item, such as those presented regularly on Friday's 7.30 segment, which is close to being unwatchable.

I don't think the ABC has any Canberra reporters. If it does, I suggest they get out on the streets away from the desk and look and ask. It's not that hard. Who knows, they might even break a story, making us sit up and take notice.

Graeme Barrow, Hackett

Professor Jenny Stewart (''Who's the greenest of us all?'', March 31st) admits that she does understand the case for Capital Metro, especially after reading the 2012 ACT submission to Infrastructure Australia. That submission was overtaken by the 2013 submission, which asked for funding for the light rail system. Between the 2012 and 2013 submissions, an ACT election was held, which resulted in an 8-8 tie between Labor and Liberals, with Green candidate Shane Rattenbury being elected to the 17th seat. A major sine qua non for Mr Rattenbury's support of the ALP to form government was the construction of a Gungahlin-to-City light rail system by 2016

Thus the ''case'' for light rail (as opposed to bus rapid transport) in the 2013 submission had to be written to support a decision, which had already been taken - imposed by now Minister Rattenbury - and the logical and economic fallacies contained in that ''case'' are easily spotted by us all! However, it is very unlikely that any of the $600-900 million funding required for the construction of the project will be provided by the current federal government and certainly not by 2016! Northbourne Avenue is safe from Green and White Elephants!

Paul E Bowler, Holder

Ralph Rowsby (Letters, April 4) wants to invest in Canberra's future. Why not go underground? Light rail would only add to the clutter on our roads. A subway with stations around Canberra at appropriate points would serve us better into the future.

Peter Hartley, Monash

I would like to suggest that the Archdiocese of Canberra and Goulburn consider establishing a cathedral place or plaza in the area between St Christopher's Cathedral and the cathedral presbytery. This would add an urban amenity and a breathing space to an urban centre - Manuka - that is already full of buildings and businesses.

I would imagine that there are architects, town planners and landscape designers in Canberra who would welcome the opportunity to be involved in such a project and I am sure there are people who would be willing to contribute to its realisation.

Frank Mines, Nicholls

Andrew Blakers (Letters, April 4) asserts that a wind turbine only occupies about one hectare of land, and that 200 wind turbines will be sufficient to give Canberra half its power.

There are now about 260 wind turbines installed in the Capital and Southern Tablelands regions. They cover hundreds of square kilometres and extend from Lake George to Tarago, and from the Hume Highway near Gunning to Bannister, and from Bannister back east towards Goulburn. If 200 wind turbines truly could have occupied only 200 hectares, well Mt Stromlo would have been a very convenient place to fit them, with plenty of room left to build houses.

George Papadopoulos, Yass, NSW

Elizabeth Farrelly (''Exit Pell, not with a whimper but a bombshell'', April 3, p5) is rightly astonished by Cardinal George Pell's proposal to insure priests against being sued for child sexual abuse.

In earlier statements, Pell had advanced the remarkable argument that his church has no legal existence and is therefore not responsible before the law for the actions of its priests.

Pell's views sit oddly alongside the words of Jesus as recorded in Matthew's gospel, chapter 18: ''Whoever causes one of these little ones who believe in me to sin, it would be better for him to have a great millstone fastened around his neck and to be drowned in the depths of the sea.''

In this, as in other areas of life, the founder of Christianity tended to call a spade a spade and cut through legal sophistry. In addressing moral issues he didn't show much interest in statistical risk management, either.

Although there has been little evidence of it in media reporting to date, one profoundly hopes that witnesses from all church organisations at the royal commission recognise their accountability to a higher court as well as to Australian law, and do not pretend there is a legal escape clause for moral failure.

Those who have suffered from their sins of commission and omission deserve apology and restitution, but nothing can restore what was taken away from them as children.

No insurance company on earth can provide a remedy for that.

Ray Edmondson, Kambah

The diatribe against Cardinal George Pell by Elizabeth Farrelly is libel that plumbs the depth of irrationality.

Not only does she totally ignore the strenuous efforts by Cardinal Pell to address the perfidy of child abuse by a minority of clergy but she goes even further than the Dawkinses, Hitchenses and Frys of the commentariat. Senator [George] Brandis' extraordinary statement that people have a right to be bigoted has been taken to heart by Elizabeth Farrelly with obvious delight.

The Canberra Times missed a great opportunity by printing this comment on April 3 rather than April 1. It would have set it and its author in proper context.

Fr Kevin Brannelly, Parish Priest, St Jude & St John Vianney Parish, Weston Creek

We should be concerned that the current and a previous treasury secretary along with the Reserve Bank governor are urging an increase in the rate and/or base of the GST.

It should be observed that these people are concerned solely with economic matters, not their social effects. John Howard's GST was a huge redistribution of wealth to the wealthy. Like most indirect taxes, it is not progressive, it is regressive.

Prior to the GST, the Australian Taxation Office had a motto: ''Taxation according to ability to pay''.

It no longer does or should voice this maxim. A further move towards regressive taxes would be a blow to the more needy.

T.J. Marks, Holt

Martin Parkinson has thrown the gage down. He wants to raise the rate of GST and spread the liability. I would go along with that provided that he would accept the following items to expand the tax.

1. Introduce a Commonwealth land tax throughout Australia at a rate not less than the average for the year of the Reserve Bank interest rate.

2. Abolish the deductibility of interest from the income of any and all taxable entities.

3. Abolish all items of ''taxation expenditure'' known to the Treasury.

4. Introduce a tax on each and every movement of funds to and from any foreign account.

5. Introduce into the Income Tax (Assessment) Act a definition of ''income'' in the following terms: ''The income of an individual or entity in a given financial year is the accretion of power to satisfy material needs.

''It embraces all receipts increasing command over society's scarce resources, that is to say, the net accretion of economic power in the entity or individual during the financial year, irrespective of how much or how little of that command is actually exercised in consumption.

''It is the change in the value of property which matters, and not the process by which that change has been brought about.''

6. Abolish the privileges from taxation now extended in the case of the taxation of capital gains.

Jim Staples, Bywong, NSW

Perhaps Canberra Times readers will relate to my experiences over recent years with the ''cash economy''.

Many sole trader contractors - from mechanics to plumbers and gardeners - have no reticence at all about asking for cash payment and will often skip the receipt unless specifically asked.

This practice has always seemed unbecoming to me - and even risky in its transparent evasion of income tax. Evidently, however, the Aussie larrikin culture and blokey code of not ''dobbing'' provides almost universal protection from being pulled up on the rort.

As a salutary observation to others who have tolerated this manoeuvre, I offer the advice that the cost of not getting that receipt can be much more immediate than just the vaguely uncomfortable knowledge that our avuncular new mate in overalls is offloading the tax burden on to others.

A gardener employed to tackle a backlog of gardening tasks in my yard also managed to cut into a mains pressure irrigation pipe, causing a slow leak that was not apparent until the bounder was long gone with his handful of cash.

The rectification was several hundred dollars and, lacking a receipt, the slippery trader knows I will have trouble proving he ever set foot on my property, and blissfully ignores my calls and correspondence.

I encourage others to demand a receipt (as I will in future), and I encourage legislators to sensibly acknowledge the rampant culture of income tax dodging by turning the GST knob up to about 15.

Ross Kelly, Monash

The ACT Auditor-General is taking a one-eyed view of water pricing (''Water price cut in doubt after audit'', April 3, p1). The main reason for the outrageously high price is obviously the decision to build the huge Cotter Dam enlargement on the lower Cotter River. It needn't have been so large. After the recent long drought, Actew clearly overreacted to the near emptying of our slow-filling, stand-by supply, Googong Reservoir. It's now full, and its drought-proofing role is operational.

Before that drought, the upgrading of the Mount Stromlo water treatment works had been irresponsibly delayed for cost reasons. The works could not therefore treat gravity-fed water from our main supply, the two fast-filling dams on the bountiful upper Cotter River. Bushfire pollution didn't help. So Googong was excessively drawn upon, causing that near emptying.

I guess we can't sue those responsible, but we certainly don't deserve to pay the huge water prices demanded, and apparently thought reasonable, by the Auditor-General. Actew must return prices to the regional norm. It could recoup its Cotter Dam enlargement by selling water (as many suspect it always intended to do) from that dam to the Murray-Darling Basin Authority.

Jack Kershaw, Kambah

Nick De Weeden (Letters, April 3) should know that ACT road rules stipulate that, when on a dual-lane road, motorists should travel in the left lane when practicable.

I have observed drivers getting into the right lane for a right-hand turn up to two kilometres early. This is not only irritating, but unlawful.

In Canberra, where one only has to put on one's indicator for traffic to slow to let you change lanes, there is no need to breach the traffic ordinance.

Howard Carew, Isaacs

YES AND NO, MINISTER

Arthur Sinodinos' appearance before ICAC last Thursday has demonstrated that he's not corrupt; just greedy, absent-minded and not financially literate. Just the qualities needed in a ministerial role with financial responsibilities.

Graeme Rankin, Holder

TACKLING THE BUDGET

The attempts by the PM and Treasurer to soften up Australians for their first budget are painful to watch. Just think about capital gains tax, superannuation, novated leases, dividend imputation. All of the Liberal Party's changes to these have been for the benefit of the well-heeled. Scrapping the carbon and mining taxes is plain dumb. It is obvious why when the PM and Treasurer played rugby they were both forwards.

Ray O'Brien, Wavell Heights, Qld

OFF THE RAILS

Canberrans are generally a canny lot and even the prospect of a ''Liberal'' majority in the Assembly may not be enough to stop them showing their disapproval of the nice but far too expensive light rail proposal come 2016. The economics are as rubbery as a boiled egg soaked in vinegar, and about as palatable.

Jon Stirzaker, Latham

CARTOON HERO

I feel sorry for Peter Baxter (Letters, April 1) having no sense of humour regarding David Pope's editorial cartoons. I wonder if he felt the same offence at cartoons with Julia Gillard and Kevin Rudd? While Tony Abbott provides such gems for the cartoonist, who could resist temptation to portray them? Long may David Pope reign as cartoonist extraordinaire at the Canberra Times.

M.E. Taylor, Page

SUMMER DAZE

Climate change is ''boring'', according to John Moulis (Letters, April 4). So boring that it stirred him into writing to tell us all that we don't ''believe'' in it any more. Given the likelihood of El Nino conditions next summer, I think the only thing Mr Moulis may find boring will be the number of very hot, dry days.

Douglas Mackenzie, Deakin

RACE AGAINST TIME

The Australian warship Ocean Shield arrived in the search zone for the missing Malaysian airliner last week. It's fitted with a ping detector for the plane's black box. The ship travels at 5km/h and the detector has a range of 4km. How many days will it take to scan the search zone, which has an area of 240,000 sq km? If additional ships join the search, how many extra ping detectors are needed to complete the search before the battery in the black box runs out in four days?

Luciano Quadraccia, Chapman

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