Light rail could be beneficial environmentally by reducing fossil fuel emissions from cars, and radically by replacing electricity generation from fossil fuel combustion by anhydrous ammonia. There are precedents, such as ammonia-driven rail cars in New Orleans from the 1890s, and buses in wartime Brussels when diesel was reserved for military purposes.

There is a well-established industry of ammonia manufacture for fertilisers, and now it can be synthesised from atmospheric nitrogen and water, using clean renewable energy from solar thermal and wind power. Traditional petroleum and diesel engines can be modified at modest cost for ammonia combustion, which causes less engine wear and tear, its combustion emissions being nitrogen and water. Ammonia can be safely stored in cylinders at 150 psi, is less expensive than fossil fuels, and can also be used to drive turbines for electricity generation (www.greenNH3.com).

The ACT government is committed to reducing Canberra's carbon footprint and given imagination and determination, could provide more employment in the manufacturing and transport sector and make it the green mobility capital of Australia.

Bryan Furnass, Hughes

Don't get me wrong. I like the idea of a light rail service between Gungahlin and Civic almost as much as Kevin Cox. His slightly ragged economic justification may have a touch of the voodoos about it but his funding idea for fat controller Shane Rattenbury's toy train set was not a bad idea: tax property owners along the route, tax them hard, and presumably often.

I'll offer another for Andrew Barr's consideration: start a subscription service a la the ill-fated Immigration Bridge for people to have a ''station'' named after them, get to drive Thomas (or will it be Shane?) on his first trip and choose his colour for a cool mill; $100K to get their moniker on a carriage; $10K for a plaque embedded between the rails; and for $1K, a wooden commemorative medallion with the fat controller's visage on one side and an image of the Titanic on the other. Naturally, all subscribers would receive an inscribed, environmentally sustainable millstone for their mantelpieces.

Jon Stirzaker, Latham

Fact and opinion

I note that The Canberra Times, along with other Fairfax papers, calls the former government's scheme the ''failed home insulation program'' in its reporting of the royal commission into it. As The Canberra Times fails to use quotations, this appears to mean that the failed nature of the program is accepted as a fact.

However, I have never seen the paper confirm this fact based on evidence. In terms of the stimulus provided to the economy through this program, there is evidence that the measures announced by the former government did help the Australian economy to survive through the global financial crisis.

If the measure of failure is the number of house fires, then there is evidence that the rate of fires was certainly no greater than the normal rate. If the measure of failure is the number of deaths of installers, then there is evidence that this was certainly no greater than in the construction industry in general. While fires and deaths are always tragic, the fact that they occur cannot be used as the sole evidence in assessing the impact of public policy.

In the end, the failed nature of the program is a purely political position and it's unfortunate that the opinions of journalists and editors have moved from the comments section to the main reporting pages.

Anura Samara, Switzerland

Problem identified

Bravo, Julian Cribb, for telling it like it is (''The cost of the scientific illiteracy of our political class'', canberratimes.com.au, May 14).

Widespread scientific illiteracy among our politicians has driven the plethora of bad decisions in the budget, decisions that are both economically and environmentally damaging.

This paragraph of Cribb's was particularly telling: ''A good many politicians clearly do not understand climate science, probably because they are too lazy to read any and instead rely for their opinions on vested interests and ignoramuses who donate big political funds. It is a form of national lobotomy by greed.''

Hear, hear!

Jenny Goldie, Michelago, NSW

Vote for wind turbines

It is OK that the sight of wind turbines scattered across our countryside is unpleasant for individuals like Dr Judy Ryan (Letters, May 5), but a very senior federal politician should keep his scathing comments to himself.

I like the appearance of wind turbines. I have admired the vista of the far Bungendore hills across Lake George while driving south on the Federal Highway, the 90-odd tall masts and twirling blades of wind turbines lit by the setting sun. They sure beat suburban streets lined with ugly multiple-wire poles.

I like birds, but Ryan's dead bird count due to the ''killing efficiency'' of wind turbines is hardly an issue. Aircraft claim a higher toll, and there are far more of them. Further, cats and dogs take a larger toll on birds and indeed on our native fauna in general. At a much more serious level, cars, trucks and buses kill people. Have we eliminated or banned these?

She adds that in high winds the turbines have to be shut down. This is a furphy. The twist angle of the blades is adjustable, like prop aircraft, to widely alter the rotational speed, and the assembly can be rotated in the horizontal plane to maximise (or reduce) the impact of wind speed. Only gale-force winds, which are rare, might necessitate a switch-off.

Greg Jackson, Kambah

The right decision

The public's right to know what the government is doing (or has done) in its name has been taken to a historic level with the royal commission on the Labor government's bungled home insulation scheme setting aside cabinet confidentiality to allow former prime minister Kevin Rudd to give a full and frank account of what transpired.

This is democratic accountability, transparency and public scrutiny being given its true meaning.

Governments must be accountable to the people and not hide behind spurious cabinet confidentiality rules.

Rajend Naidu, Glenfield, NSW

I dutifully endured the unedifying budget speech and subsequent analysis and interviews on the ABC before resuming, in some dismay, reading Paul Verhaeghe's What about Me? the struggle for identity in a market-based society. Within minutes, I came upon a short passage that perfectly summarised the situation: ''The economy must serve society, not the other way round. That sacrifices will have to be made is clear; we are living far beyond our means in the West. But those sacrifices should benefit society, not the economy. Anyone who finds this statement surprising should be more surprised at themselves.'' (p220)

Ignoring the bellowing elephant already beginning to wreck the room - this government's reckless negligence in dealing with renewable energy and climate change (a problem that renders the old shibboleth that the best way to benefit society is to grow the economy not merely threadbare but now dangerously simplistic) - were there any initiatives in the budget designed to benefit society? Possibly the new health research facility and building infrastructure; not much else.

Both are essentially robbing Peter to pay Paul via hypothecated funding from user charges. In the first instance, this risks sacrificing immediate health in the hope of securing wonderful new cures sometime in the future. The second is simply a classic case of ''putting out a fire with gasoline''. The evidence is clear: attempting to solve congestion by building bigger roads simply leads, in a very few years, to bigger congestion.

Is this really the best we can imagine?

Felix MacNeill, Dickson

The budget has penalised ordinary Joe but not big business. All unsurprising, coming from a Coalition government.

Joe Hockey talks of future objectives but is there evidence of that? Take a single item, infrastructure, reasonably defined by Wikipedia and others as ''the technical structures that support a society, such as roads, bridges, water supply, sewerage, energy supply (electricity and renewables), telecommunications, etc''. The Coalition seems to have limited the definition to roads only, and committed billions to them, much of it to urban roads. No mention of the other elements.

So are the urban roads objectives futuristic vision? Absolutely not. For many years Sydneysiders and their other Australian urban cousins have witnessed never-ending roadworks attempting to meet ever-growing traffic congestion. Where are they today ? Despite urban sprawl to the north, south, and west, Sydney is described at weekends as a moving car park. While urban populations continue to grow at current rates, more roads will provide at best temporary relief from congestion and increase the infrastructure stock requiring future maintenance for which no money is put aside. And afterwards the congestion problem will have simply grown bigger and our pollies will again talk about more roads.

Obviously the long-term answer is not more roads but either fewer cars (forget that) or limitation of urban populations, a question involving our immigration numbers and public support for high natural birth rates. But while big business continues to dictate to both the ALP and Coalition that economic growth based on population growth be fundamental to both their policies, there'll be no relevant debate and we'll not be offered an alternative.

Vince Patulny, Kambah

State governments could better handle the cuts to their budgets if the federal government were to take measures to significantly reduce the annual increase in their populations. One controls the numbers, the other has to provide the schools, hospitals and other infrastructure.

Steve Thomas, Yarralumla

Round one to Hockey

The conversation on Australia's finances has now changed and there is no turning back. Joe Hockey has delivered the first salvo in the new era. Labor and the Greens have yet to engage in the conversation. The Greens are activists with no chance of ever being in power and will never really join the conversation that Australia must have. Labor must join the conversation, and after squandering most of his credibility on populist sniping, Bill Shorten will eventually be dragged kicking and screaming into reality. Not a perfect budget by any means, but an excellent start. Well done, Joe.

H. Ronald, Jerrabomberra, NSW

Back to the Dark Ages

Surely the prosperity of a country means running the economy efficiently and with intelligence.

Yes, we need to live within our means, but we also need to invest in initiatives, research and development on all levels. Cuts to education, grants and innovation related departments will only hurt Australia.

Obtaining income from digging holes in the ground to supply finite resources such as coal to countries which will one day find other types of fuel is shortsighted to the point of being blindfolded. We need to be much smarter.

Not every Australian needs to become a scientist, but anyone should be able to take an idea and turn it into profit for themselves and the nation and to create jobs for others in Australia, rather than taking their business to less risk-averse shores.

As a business partner in the development stage of a children's educational app, we need support. If the app becomes a success we would seek to employ local staff, as our current efforts in using overseas developers is proving to be extremely problematic. Recently we sought a grant. A likely option would have been the Screen Australia Games Production program. However, applications closed as of May 14 due to Tuesday's budget cuts.

This budget may eventually get our nation into the black but it will also take us into the Dark Ages.

Adrienne Gross, Weetangera

David Wroe's article ''Flying into the future drone zone'' (May 10, p16), written following a trip to the US courtesy of drone-manufacturer Northrop Grumman, is strong on gee whiz potential for these remote killing devices. However, some critical issues rated little more than a mention. If the RAAF is keen to overcome the ''negative public perceptions'' about these weapons, it would do well to address the concerns held in a transparent fashion. There is no sign of that happening.

Wroe states that some argue that the strikes in Pakistan, Yemen and Somalia could be illegal. Could be? What can be lawful about choosing people whom one thinks have committed a crime, or might be planning to, and bumping them off, along with bystanders? Drone killings totally undermine legal process, the very basis of our security. If there are no ethical or legal qualms against such precedent, then how would one view enemy forces using drones to attack suspicious individuals in, say, Washington, DC, or Sydney?

The problem of drones bringing a new level of terror to civilian populations and creating new enemies for us, to which Wroe briefly referred, should also be central in any discussion of their utility. The Stanford and NY Universities 2012 study Living Under Drones estimated that the number of high-level targets killed as a percentage of total casualties is just 2 per cent.

As for Pine Gap, former PM Malcolm Fraser is correct that the base has played a key role in US drone strike targeting. Australia is already culpable. Transparent discussion is overdue.

Dr Sue Wareham,

vice-president, Medical Association for Prevention of War (Australia)

VOTERS SLOW TO LEARN

Why do we so often vote in conservative governments that promise prosperity for all, but then, as soon as they gain power, break their promises and give us cuts to welfare, health and education, while rewarding companies and high-income earners? Haven't we learnt our lesson yet?

David Hicks, Holt

I did not notice any mention in the federal budget of cuts to public funding of political parties. Why not, when such a cost saving would have been universally approved? Perhaps, to paraphrase Orwell, all entitlements are equal, but some are more equal than others.

Nick Payne, Griffith

From Juliar to Joliar. How quickly times change.

Gene Schembri, Cook

With admirable restraint, the Australian political media has refrained from calling the Treasurer ''Joe-Liar'' including, notably, the acerbic Alan Jones. While it rolls nicely off the tongue, they all know who the real Pinnochio is.

D .A. Nolan, Nicholls

The biggest liars in federal politics are those in both government and opposition who claim to be Christian while planning or condoning the cruel treatment of asylum seekers or planning to build themselves a grand reputation at the expense of the most vulnerable in our society. Like John Howard before him, the most enduring ''infrastructure'' Tony Abbott will leave behind is the self-interest built into an economy that favours the wealthy and healthy at the expense of those who live with disadvantage.

Ruth McLucas, Weetangera

LABOR, WAKE UP

Peter Martin (''High price of crying poor'', Times2, May 13, p1) unintentionally makes another great case for broadening and raising the GST with his populist attack on a tiny handful of people scamming negative gearing to avoid paying much tax (I'm sure they pay plenty of GST). Don't tell us Peter, tell Bill Shorten and the ALP.

Christopher Smith, Braddon

BUS TO SYDNEY IS BEST

I have given up trying to get to Canberra Airport (Letters, May 12) and take the bus from Civic to Sydney Airport instead.

Bruce A. Peterson, Kambah

ADVICE FOR SESELJA

Instead of complaining that the Liberal leadership does not pay him attention, Zed Seselja could vote with other parties when that would benefit his electorate, the ACT. That would make people pay attention in the new senate.

Peter Campbell, Cook

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