Like most, you enjoy all the benefits of what you refer to as the British invasion yet somehow pretend that it should never have happened. Do you seriously think any Australian, including our Indigenous people, would ever want to return to a pre-colonial life given the chance? If those hankering for some mythical nirvana packed up and lived in bark huts without any of the trappings of the modern world, I would respect this view, otherwise it is just nonsense.

It would be far more productive if we all accept reality and move forward together.

H. Ronald, Jerrabomberra

The report of mysterious "sonic harassment attacks" on the USA's diplomats in Cuba are reminiscent of the microwave attacks by the USA's embassy in Moscow during the 50s through to the 70s ("US anger at brain injuries", September 3, p12).

At the time it was claimed that the microwaves were designed to reduce cognitive capability.

The USSR neither confirmed nor denied the accusations. Rather, it commented that the exposures cited were lower than the USA's industrial safety standards.

Gary J. Wilson, Macgregor

Tony Auhi ("A Burning Issue", September 3, p15) says "There are smarter ways to deal with waste than burning."

Absolutely; if it were legislated that all materials were durable by design, repairable and ultimately recyclable then there would be no waste requiring disposal.

For now, we accumulate non-recyclable wastes which are only disposed in land fill or escape to pollute the landscape and oceans. If not eliminated, they should be combusted in a thermal waste treatment plant (not an incinerator) thus disposing the waste and recovering the embodied energy while ensuring zero emissions.

Dick Varley, Braidwood

Maria Pellegrino asks: "Why is it OK for Dr Kerryn Phelps to be part of the 'yes' campaign while not OK for Dr Pansy Lai to be part of the 'no' campaign?"

Maria then says: "Those demanding Dr Lai be struck off by the AMA are doing the 'yes' campaign a great disservice" (Letters, September 8).

While this is not a petition I would have initiated, and GetUp! has removed it as contrary to its standards, I do think there is a misinformation campaign from the "no" side that distorts every action of those of us wanting equality for fellow Australians.

The petition asked the AMA to review her registration. It did not demand she be struck off.

The cause for concern is Dr Lai's now sotto voce support for gay conversion therapy, a totally discredited approach which starts with the false assumption that homosexuality is a disease.

The difference between Dr Lai and Dr Phelps is that Dr Phelps does not support harmful "treatments" for a "disease" that is not a disease.

The "no" campaign is based on red herrings and non sequiturs. Its focus cannot be on the real issue of equality so it throws up a range of furphies to "bolster" its case.

John Passant, Kambah

For environmental reasons, Cheryl Smyth (Letters, September 7) quite rightly condemned the Cambridges for bringing a third child into the world. All humans produce bodily wastes, CO2 and other nasties. And even if we drastically change our behaviour, our local and global population still needs to be reduced significantly if we wish to live in an ecologically sustainable manner.

Mark Sproat (Letters, September 9) did not understand Ms Smyth's message, as he suggested her ire should be directed towards those who have three or more children but cannot afford to raise them rather than those who can.

It's about the environment, Mark, not money! I don't know if you have children or grandchildren, but if you do, and if you love them, surely you don't want to leave them an overpopulated, polluted sewer?

Rod Campbell, Ainslie

We now have the almost-delicious picture of the neo-liberals and laissez-faire disciples in the Coalition contemplating the nationalisation of power stations. That's socialism, folks!

That this call should emanate first from the Nationals will actually come as no surprise as the erstwhile "agrarian socialists" have always been fond of taking good tax money to fund lost causes and subsidise their better-off constituents, preferably while no one was looking.

It highlights the absurd lengths that the climate change deniers within the Coalition will go to prevent the imposition of carbon pricing and, in turn, prevent electricity providers from making reasoned investments in infrastructure, the very thing they want to happen.

But then again, reason and science "don't come into it" for these irrational ideologues.

David Jenkins, Casey

While Malcolm Turnbull and Bill Shorten fight like tomcats over gay marriage, the US military sees the biggest threat to global security as global warming.

In America, hurricane scientists say they've never seen anything like this in the modern record. Satellite images show multi-hurricanes currently lined up. What hope has America got of reducing carbon emissions when President Donald Trump's first foreign trip was to Saudi Arabia to sell guns and buy crude oil?

What happened to Prime Minister Malcolm Turnbull's big increase in Snowy electricity? Not yet.

Climate scientists warn us that 7billion people burning fossil fuels will make extreme weather events (cyclones, tornadoes, floods, blizzards, droughts, heatwaves, rising seas, monsoons, bushfires) even more extreme.

What impedes cutting carbon emissions is huge profits from coal and oil.

To protect their interests, coal and oil companies give huge bribes (sorry, donations) to help the Coalition win the next election. In Canberra, money comes first.

That will require replacing carbon energy with renewables. Especially as old coal-fired power stations shut down one by one as the Coalition does nothing except to blame Labor and labour unions.

The Coalition consists of sick people with no cure except an election.

Graham Macafee, Latham