In a study published last week in the scientific journal Nature, scientists say Australia must keep 95 per cent of its coal in the ground if we are to have any hope of stopping the planet warming beyond the crucial limit of 1.5 degrees.

Yes, in the three months to July Australian coal exports had grown in value by 26 per cent to $12.5 billion, but it does not mean coal has a future beyond 2030 as Resource Minister Keith Pitt claims. Professor John Quiggin from the University of Queensland explains that this "recent increase in prices was caused by a combination of the rapid recovery from the pandemic recession, rising gas prices, weather-related disruptions to coal supply from Indonesia, and drought in China. It's worth noting that despite high prices, the volume of seaborne thermal coal has actually declined".

Quiggin argues that it is easy to phase out at least thermal coal within the decade, largely through replacing coal-fired generators with roof-top solar. The transition for workers will be less easy but solutions lie in "a mixture of measures including early retirement, retraining, and investments in renewable energy targeted at coal-dependent regions".

The AIS has announced that it is closing the fitness centre after the lockdown is over. This means that classes such as pilates, tai chi, and other land-based fitness classes will no longer be held.

I understand they will open the pool for swimming and swimming classes, but not for aqua aerobics. These water-based classes provide immense support to many in the community who have mobility issues such as arthritis or after knee or hip replacement surgeries.

I have been attending these classes for more than 20 years and have found that exercising in water has incredible benefits, especially as I age.

I am in my late-70s and have found the aqua classes to be the centrepiece of my fitness regime. Apart from the dedicated instructors losing their jobs, many of us "oldies" will now have to try to find other venues to continue to exercise.

How disappointing to receive an email on R U OKAY day saying the AIS fitness centre is closing permanently because it is no longer "commercially viable".

I attend aqua fitness group classes three times a week. The sessions are always very well-attended. Given that the pools will remain open for public swimming and learn to swim program why not keep the aqua group classes?

Seniors are the main participants. It is extremely important for this group of people to have exercise and interaction. Many friendships have been formed over a long period of time.

I am a relative newcomer having only joined in 2008. Many people have been active members for almost 30 years. Let's hope the AIS Aquatic and Fitness Centre reconsiders this decision.

Clive Williams ("September 11 attacks caught Australia unprepared, too", canberratimes.com.au, September 9) wrote that the attacks caused a recalibration of the Australian government's efforts to that of combating terrorism.

This was also the case for many other countries. Unfortunately this has been at the cost of a 20-year diversion of resources and attention from tackling the real international issues of climate change, catastrophic biodiversity loss, pandemics, extreme stresses on food, soil and water resources, and global inequality.

In 1992 all countries signed on to Agenda 21 at the UN Rio Earth Summit. On September 11, 2001, I was living in New York, working at the UN headquarters on preparations for the 2002 UN Summit on Sustainable Development, at which all countries signed onto a global plan for sustainability.

I suggest the Western invasions of Afghanistan and Iraq, upheaval in the Middle East and the focus on terrorism has cost humanity at least 20 years of lost focus on the far more deadly threats of climate change and other threats mentioned above.

Let us hope that after the West's withdrawal from Afghanistan Australia and the rest of the world "recalibrates" to deal with the threats that really will effect the future of our children and grandchildren.

I've been curious about what the COVID-19 case numbers are like in places that have high vaccination rates because I look forward to getting out of lockdown.

I took a quick look at the vaccine uptake in the well-educated and relatively wealthy county of Marin, in California USA. I found that 89 per cent of the population are fully vaccinated and 96 per cent have had at least one jab.

Marin County has a population of 257,000 - just over half the size of Canberra's. They have been having, over the last month, between 10 and 35 new cases a day. Very interesting.

I am concerned about the vulnerability of many of our mid-teens to COVID-19. Our supermarkets and fast food outlets employ many of them from 14 and up.

Many of these supermarkets and fast food outlets have featured as hot spots recently. Fast food outlets in particular depend on teens for their financial survival.

Vaccinations for this working cohort of 14- and 15-year-olds should be expedited along with those from the special schools already mentioned by the government.

With ACT residents presently under lockdown and stuck at home 22 hours a day, seven days a week, it is extremely mean of the ACT government and its agencies to be subjecting many thousands of residents across numerous Gungahlin suburbs to excessive noise from hundreds of heavy truck movements on a daily basis.

The trucks are hauling excavated material from the government's major developments across Canberra, and milled road surface materials from ACT roadworks across Canberra, via Horse Park Drive, Gundaroo Drive and Mulligans Flat to various properties in Sutton where the materials are dumped, much to the chagrin of local residents and Yass Valley Council.

The practice has been going on for approximately six months, and for a few weeks in April and May was even undertaken throughout the night. In recent times truck movements have increased dramatically.

The engine noise, the rumble of compression brakes, the vibration and the diesel fumes from 6.30 every morning is maddening and unbearable. And there is no escape.

How is such a practice at all sustainable on environmental, economic or social grounds?

On Friday, September 3, the Australian Technical Advisory Group on Immunisation (ATAGI) stated that students aged 12 to 15 are "of a lower priority than older adults" when it comes to vaccination.

Its advice stated: "ATAGI therefore recommends that all strategies are considered including provision of choice of vaccine to ensure that older adults are vaccinated."

ATAGI further stated that the direct benefits of vaccination in preventing severe COVID-19 are greatest in the over-60 group. In NSW to September 3 there were 18 deaths from COVID-19 in the 10- to 59-year age group. There were 163 deaths in the 60- to 90-plus age group.

Since the ACT is surrounded by NSW and the COVID-19 case load is increasing rapidly it would seem a "no-brainer" to allow access to the Pfizer vaccine for the over 60 cohort to ensure our limited hospital and ICU resources are not overwhelmed.

Many seniors are already doubly vaccinated with Astra Zeneca so granting Pfizer vaccine to the small number who are still waiting would not have a huge impact on the rest of the vaccine rollout.

Why are we not adopting ATAGI's recommendation on this one area when we have followed every other recommendation? Could it be, as suggested by Karyn Flynn (Letters, September 7) that our politicians think seniors are expendable?

The former Melbourne home of prime minister Robert Menzies and his wife Pattie in suburban Malvern has just been demolished.

This for a man who served as PM from 1939 to 1941 and 1949 to 1966 and founded the Liberal Party. It suggests we don't care much about our history. Most other nations would have preserved the home.

Thank you for the weekday comics. What a laugh, a pleasant boost to counter endless doom and gloom. What inoffensive pleasure they are while still being rather clever. Unlike letters that attack people these comics make fun of vague policies.

Aren't we missing the point about the PM's home jaunt? Shouldn't he and his family be living in Canberra in the home built for the Prime Minister, the Lodge?

I wish COVID-19 had started in Las Vegas. That's because what happens in Vegas, stays in Vegas.

Claiming "millions are unable to visit loved ones" strikes me as mischievous ("Deja vu: PM scrambles over Hawaii 2.0"). Why not write: "Millions are unable to return home to their wife and school-age children at their normal Sydney residence?" Because it's more obviously false than comparing an apple with a case of oranges, that's why.

If Scott Morrison had chosen to live in the Lodge he would not have had to make endless trips to Sydney; the family would be with him in Canberra.

Why do our prime ministers no longer live in Canberra? There would have been no need for Mr Morrison to go to Sydney for Father's Day if his family was in Canberra.

While Victorian, most NSW and ACT residents remain locked down the Prime Minister roams the country because he likes to remind us common folk he is the Prime Minister. Given that display of arrogance you might ask "for how much longer".

On behalf of Bronwyn Bishop, Sussan Ley and other rorters I believe Scott Morrison must now do two things. First, tell taxpayers how much his Canberra-Sydney-Canberra flight for Father's Day actually cost. Second, pay that amount back.

The simple solution to cut through vaccine hesitancy in older adults is to follow the latest ATAGI advice and give all adults a vaccine choice. Given we have been told the vaccine drought is over it's about time ScoMo moved on from his boast of "following the medical advice".

If the government says that the information released under FOI does not tell the full story of the Pfizer debacle then maybe it should release all the relevant papers to support that claim. I'll wait.

Someone should remind Peter Dutton that the job of the Defence Department is to fight wars, not start them ("Dutton compares China to 1930s Nazis", canberratimes.com.au, September 9).