What Causes Climate Change?

With all the massive publicity given to the issue of climate change, in particular global warming, over the last decade, it's an important exercise to look at the possible causes of this, particularly as it now has assumed major international political dimensions.

We can talk about “temperature change” in close parallel with “climate change” as temperature is the main driver of our climate system. Changes in temperature patterns produce a large variety of “knock on” effects such as variations in rainfall, humidity, snow, cloud cover and wind regimes around the world.

We know from so called proxy data that global temperatures have varied considerably across the known history of the Earth, over periods of millions of years. Climatologists studying such data as ice cores, rock structure, lake sedimentation, glaciers, fossils and tree rings have been able to build up at least a rough picture of our past temperature patterns.

From what we understand, the temperature time line of planet Earth looks something like this – where "mya" means “million years ago”. The reference line shown in red is the present global temperature and we see there are numerous instances where this line has been exceeded (warm epochs) and others when the reverse is the case, the times of Ice Ages.

The obvious question follows – what could be producing these variations?

In fact several likely causes have been identified, all of them entirely natural except one where climate scientists say there may be a human “footprint” – the so called anthropogenic effect.

This is a summary:

Milankovitch cycles: A sequence of “wobbles” of the Earths rotational axis and irregularities in its orbit around the Sun that occur over long periods and were first identified by the Serbian astronomer Milutin Milankovitch early in the 20th century. These cycles produce periods of warming and cooling in the Earth’s climate over time scales of several thousand years.

Serbian scientist Milutin Milankovitch - discoverer of the so - called Milankovitch cycles. (Image from Wikipedia commons)

Impact from extra terrestrial bodies: Large meteors and possibly even comets have collided with the Earth over past millions of years and these have strongly affected the climate. With a collision of this type a vast amount of debris is injected into the atmosphere and this can shield the surface of the Earth from solar radiation for extended periods, resulting in substantial cooling. It is suspected that one such collision around 65 mya produced a much cooler global climate for several thousand years, resulting in the demise of the dinosaurs.

A NASA impression of the giant collision of 65 mya that led to the extinction of the dinosaurs. (Image form Wikipedia Commons)

Continental drift: The world’s great continents actually move relative to each other at very slow rates of only a few millimetres a year. But over millions of years this movement becomes significant with different distributions of land and ocean resulting and changed patterns in ocean currents. These currents flowing around the world play a major role in transferring surface heat from tropical latitudes towards the polar regions and these have a major impact on climate patterns. The Gulf Stream, for example, produces much warmer weather for the United Kingdom and western areas of Scandinavia than areas of similar latitude in Canada. Disruption of these ocean currents, caused by continental drift, would certainly produce significant climate change.

Volcanoes: In a similar fashion to meteor impact, volcanic eruptions can inject massive amounts of dust into the atmosphere that result in solar shielding and global cooling. The 1815 eruption of Mount Tambora in Indonesia was a major cause of the so-called “Year without a summer” in 1816, when abnormally cold temperatures spreading across England and Europe produced widespread crop failures and famine.

The Mt. Pinatubo eruption in the Philippines, 1991. (Image from Wikipedia Commons)

Cosmic rays: These are high-energy particles that constantly bombard the Earth’s atmosphere. They are thought to originate from outside our solar system and could be produced by massive supernovae, or stellar explosions, from far distant stars. It has been speculated that the “gusts” and “lulls” in cosmic ray activity could produce climate change but this remains an area of controversy.

Variation in solar power: Observations in the power output of the Sun shows it to be variable with several known cycles. These include those of 11 years, 88 years, 208 years and 1000 years. There are probably more and these would have some type of impact on our temperature and climate system, although the specifics are far from clear

The Sun - power emitted varies over several different time scales (image from Wikipedia Commons)

Changing gas concentrations within the atmosphere: Our atmosphere contains a mixture of gases, with the so called “greenhouse gases “, including water vapour, carbon dioxide and methane, playing a major role. These gases prevent a total escape of solar energy back out into space and keep our global temperature warmer than it otherwise would be. Climatologists are worried that by the constant burning of fossil fuels we increase the concentration of carbon dioxide and thereby raise global temperatures. This mechanism for climate change, if real, is notably different to others in that it is produced by human activity rather than the natural processes already noted. This is known as the anthropogenic effect.

For information on how past climates have been measured go to:

http://passingparade-2009.blogspot.com.au/2009/08/measuring-past-climates.html

Bring Back National Service?

National Service has always been a highly contentious matter in Australia, particularly during the Vietnam War era when 20-year old conscripts were required to become combat soldiers in a real “shooting war”.

Ultimately some 63,000 young men were called up between 1965 and 1972 and 15,380 served in Vietnam. 184 National Servicemen died there and 880 were wounded in action.

Australian troops arrive at Saigon Airport 

during the Vietnam War - Wikipedia image

Towards the end of the war the opposition to sending conscripts to Vietnam had become very strong, with several large public demonstrations taking place in capital cities and organisations such as the “Save our Sons” group gaining considerable support.

The war had become generally unpopular by 1972, to such an extent that the then leader of the Opposition, Gough Whitlam, made the ending of conscription one of his key election issues. It certainly did play a significant part in producing a change of Government, and primarily for this reason successive political parties have steadfastly avoided any plans for the reintroduction of National Service.

The Hon. Gough Whitlam, 21st Prime Minister of Australia

(Wikipedia image)

But perhaps it was not National Service, as such, that was the basic problem, but more the way it was implemented. The selection system, involving the drawing of a marble from a Tattersall’s lottery barrel, provided a date and all 20 year old men whose birthday fell on that date were called up. The Leader of the Opposition in 1965, Arthur Calwell, described this system as the ‘lottery of death’.

Then there was the fact that conscripts were sent into a war zone. It’s bad enough when an Australian soldier is killed in an overseas war, but when a National Serviceman is killed in action, the situation becomes political dynamite.

But National Service does not have to be like this. There are ways of instituting a system that avoids these highly contentious issues and is still of considerable benefit to both the individual and to the nation.

Various schemes have been suggested over the years and here is one of these.

A call up for all twenty year olds is instituted – men and women – with the requirement for a three - month period of service. The inductee would have a choice of various electives and these could be chosen from the following areas:

The Army – a basic training course

Community work – Meals on Wheels, shopping and gardening for the elderly, work in nursing homes, Salvation Army, Vincent de Paul.

Council work – bushland regeneration

State Emergency Services (SES)

Rural Fire Services (RFS)

If Australia is involved in armed conflict at the time there would be no requirement for the conscript to become involved unless he or she volunteered and this would require leaving the National Service scheme and joining the regular Army.

“Points” could be attached to these activities depending on Government priorities, and

after a certain number was amassed, the conscript would be entitled to a subsidised home loan.

The SES in Victoria attend a vehicle accident

(Wikipedia image)

Such a scheme would be of considerable benefit to the nation. We would develop a large number of young people with basic military training that could be of great assistance in the event of mobilisation. Work in the SES and Rural Fire Services would improve our responses in emergency civil situations.

A considerable amount of useful community work would be undertaken – work which is presently in “on hold” because of the lack of people power.

And finally, such work would be of great benefit to the individual. Apart from the character building and discipline that comes from involvement in work of this type, unique networking opportunities arise from the mix of people that comes with National Service.

Would it work?

Ask not what your country can do for you – ask what you can do for your country - President John F. Kennedy, January 20^th 1961.

Drunk in Parliament - Disorder in the House

In recent times allegations have flown regarding Members of the NSW Parliament being drunk in the House, and this has led to speculation about declining standards of behaviour amongst our leaders.

But we needn’t worry too much – the Parliamentarians of today are mostly model citizens compared to many of their 19^th century counterparts.

Cyril Pearl in his “Wild Men of Sydney” described the NSW Parliamentary scene of the 1880’s as anything but an edifying spectacle.

NSW Parliament House, Macquarie Street, Sydney c 1895. (Charles Kerry Photograph)

“Violent behaviour and violent language were condoned or scarcely rebuked; fights between members were not uncommon and the sight of a drunken statesman falling off his bench during a debate excited amusement rather than indignation”.

The association between alcohol and legislation was a strong one and regarded as entirely normal. Pearl recounted that “…..a timid proposal that grog should be banned in the Parliamentary refreshment room was easily defeated”.

Sir John Robertson, Premier of NSW on five different occasions during the 19^th Century, remarked that “None of the men who in this colony have left footprints behind them have been cold water men”. Sir John restored the financial affairs of the Reform Club, when as President, he advised the members that “We must drink the bloody club out of debt”.

Sir John Robertson, Premier of NSW, c 1880. (Image from Wikipedia Commons)

The newly elected Adolphus Taylor told his supporters in 1882 that “Mudgee is represented by three good drinking men – myself, Sir John Robertson and David Buchanan”.

But perhaps the most notorious drunkard in the House was John Norton, editor and owner of the “Truth” newspaper and Member for Sydney-Fitzroy in 1898. On one occasion, during Parliamentary debate, he was removed from the House for “shouting drunkenly, to Mr. J. C. Watson, “Damn and f..  you” , and on the last night of the session he was so drunk that he urinated on the floor of the Chamber. Pearl recorded that he was then “dragged out by two constables to the accompaniment of salvos of ripe oaths and the crash of broken glass…”

John Norton, Member for Fitzroy, c 1898.

(City of Sydney Archives, NSCA CRS 54/315

Such lamentable scenes now belong in the past and the average politician of today is a hard working and effective contributor to Australian society. Any lapses that may have occurred over the last few months would barely have raised an eyebrow in the Parliament of the late 19^th Century. The election of women Members to the House has undoubtedly helped raise the standards of behaviour in this respect.