Australian Blog

  • Why coal fired power stations don’t work so well when they are old

    By on October 18, 2017

    The ageing of coal fired power stations is currently in the news with the likely shutdown on Liddell Power Station in 2022. But industrial plants and utilities shutting due to old age is actually a bit unusual, as CCL Cunningham’s Peter Todd explains.


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  • Why is the concentration of carbon dioxide in the atmosphere increasing?

    By on September 16, 2017

    To get a feel for this there is a need to set a temporal context. Homo sapiens appeared from about 200,000 years ago and it really does not matter about what the climate was prior to this time since it is highly unlikely that Homo sapiens had any impact on the climate whatsoever.   However, since ice core gas studies have been taken back to about 800,000 years before present (BP), it is useful to use this data to set a temporal context equal to this period since it reveals the natural cycles that perturb the Earth’s orbit prior to and during Homo sapiens history.

    Whilst ice core studies have been proceeding for some time, a collaborative paper by Lüthi et al. published in Nature in 2008 will be used to establish the temporal context used in this blog. This ice core study pushed the temporal limit back to 800,000 years.  Other studies have been done more recently that are trying to get back to 1 million years ago.  However, for the purposes of this blog, the duration period used in the 2008 Nature paper is adequate.

    The paper clearly shows that the carbon dioxide concentration has been cycling between about 180 and 280 ppm (parts-per-million) every ~40,000 years. This behaviour is caused by a cyclic wobble of the Earth’s orbit and is called the Milankovitch Cycle. So in a trough of the cycle the Earth is colder than at the peak of the cycle.  As the Earth wobbles away from the trough towards the peak it exposes a different part of its surface to the Sun which causes a shift in the energy balance. This change in the energy balance initiates a heating cycle, the increase in temperature takes a little time (a lag) to work but it eventually perturbs the carbon cycle, which causes more carbon dioxide to be released from oceans and Arctic and Antarctic regions and mountains etc., which in turn enhances the natural greenhouse effect by the carbon dioxide released which causes positive feedback, which further increases the carbon dioxide concentration and so on, until the wobble has finished. At this time things settle down and a new, carbon cycle equilibrium is established (~280 ppm) at the peak of the cycle until the wobble starts to head back to the trough (~180 ppm).  As described by NASA, the carbon cycle, via the greenhouse effect, is essentially the thermostat that controls the Earth’s average global tempertaure.

    The Earth is currently at or near the peak of a Milankovitch cycle which means if natural processes had continued as per normal over the last 800,000 years we should be measuring carbon dioxide in the atmosphere at very close to 280 ppm.  This is not the case since it is now over 400 ppm.  Why is this so?

    The first hint is to look a at historical measurements and it can be readily seen that the carbon dioxide concentration started to increase above 280 ppm near the start of the 19th century somewhere between 1770 and 1800.  A period which is historically associated with the start of the industrial revolution. Since carbon dioxide is a greenhouse gas (GHG), its natural attribute is to absorb infrared radiation and many people have used the positive correlation of the average global temperature increase with the increase in carbon dioxide to conclude that it is the increase in carbon dioxide that it is causing the average global temperature to increase.  This is a logical argument but it is supportive evidence and is not conclusive.

    To understand that the increase in carbon dioxide is caused by fossil fuel combustion we need to consider other possible sources.  The most popular candidate is emissions from volcanoes. Volcanoes do produce carbon dioxide but according to the BGS (2005) and the USGS (2011) they only represent about 1% of the total emissions produced by humans. Also, if volcanoes were playing a role then the graph of the observed increase in carbon dioxide would be very spikey just after a large eruption, especially if a volcano produced more carbon dioxide than produced by humans in their entire history, and this is certainly not the case. Volcanic eruptions can produce small cooling effects which lasts no more than a few years. Remember we are now considering the last 200 years or so of the peak of a Milankovitch Cycle which should have carbon dioxide at 280 ppm, which was the case just prior to the start of the industrial revolution.

    So, the next step is to examine the nature of carbon dioxide. It is made up of 1 atom of carbon and 2 atoms of oxygen.  Carbon occurs naturally as the isotopes carbon-12 (99%), carbon-13 (~1%) and as a trace of carbon-14.  The latter is made in the atmosphere by the action of external radiation (Cosmic Rays etc.) on nitrogen in the atmosphere.  Carbon-14 is radioactive and has a half life of 5730 years, in other words it decays. So, if you burn fresh carbon you get carbon dioxide which is composed of a mixture of carbon-12 dioxide, carbon-13 dioxide and carbon-14 dioxide.  If you put the latter in an isolated, closed jar for 5730 years you would only have half of it left.  This is why one can use carbon-14 for historical dating but it is limited since after 50,000 years or so it cannot be measured since there is not enough left to detect.

    So, the other factor which is often overlooked is the ever decreasing carbon-14 to carbon-12 ratio in carbon dioxide in the atmosphere, even though the concentration of carbon dioxide is increasing. The carbon-14 content of fossil fuels has long ago been lost because fossil fuels were laid down 250+ million years ago and we know that carbon-14 only has a half-life of 5730 years which means fossil fuels contain NIL carbon-14. The only source of carbon dioxide that is large enough to produce the observed dilution or Suess Effect is the combustion of fossil fuels by humans. Recall, that volcanoes do produce carbon dioxide but their GHG emissions only represent about 1% of the total emissions produced by humans.

    The same isotope analysis can also be applied to the observed decreasing carbon-13 to carbon-12 ratio. It is not that plants are lazy but they are energy sensitive and have a preference for fixing carbon-12 over carbon-13 since the former is not as heavy as the latter.  It is not a large difference but what it means is that if you were to compare the carbon-13 to carbon-12 ratio in air immediately surrounding the plant to that carbon fixed in the plant you would find that in the plant, the ratio in the plant would be less than in the air.  So, since this also applies to fossil fuels since they are made from plants, carbon dioxide formed from burning fossil fuels is deficient in carbon-13.

    Measurements of the carbon-13 to carbon-12 ratio in air are also decreasing over time which is further evidence that the carbon dioxide in the air is being diluted by carbon dioxide formed as fossil fuels are burnt. There is no other source of carbon dioxide that can cause the observed dilution or, Suess Effect. More recent studies by the Scripps Research Institute and their international collaborators also show that the global oxygen concentration is also decreasing by a small amount equivalent to that used to form carbon dioxide by the combustion of fossil fuels. This decrease in oxygen can only occur as a result of combustion. It is not dangerous, but it is just that a small change in a large background it is now measurable with good precision by modern instrumentation and the findings supplement the carbon isotope studies.

    So the logical conclusion that can be made from the known mass of emissions and the carbon isotope studies is that the increase in the atmospheric concentration of carbon dioxide observed ABOVE that expected for a Milankovitch maximum of about 280 ppm after the period 1770 to1800 along with the observed decrease in global oxygen is caused by the combustion of fossil fuels.

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  • Our Response to the Finkel Review

    By on July 8, 2017

    Our response to the Finkel Review – Rod Mitchell, National Coordinator

    ‘A potentially useful first step’ is the best way to sum up our response to the Chief Scientist’s proposal for a Clean Energy Target (CET). If Labor can support it and if the benchmark (the amount of CO2 per megawatt hour) is set low enough then, investment may begin to flow again, mostly to low emissions generators.

    It could provide an element of bipartisanship, create more certainty and inject some much-needed positivity into the climate and energy debate.

    It strives to be technology-agnostic (not favouring any particular form of generation). And it may give the PM and Minister Frydenberg some respite from their critics in the Coalition.

    The CET is only a first step because the rate of emissions reduction will most likely be too slow and the unpriced external costs of fossil fuels will remain as “hidden subsidies” to coal and gas. The work of CCL remains vital for three main reasons:

    • Carbon Fee and Dividend ensures the full costs of all fossil fuels are included in their price; this makes a truly technology-agnostic solution possible.
    • The CET only applies to the electricity sector, whereas Fee and Dividend would reduce carbon emissions across the whole economy, as well as encouraging other economies to do the same, through border adjustments.
    • We will need deeper and faster emissions reductions than CET can deliver, even if the benchmark is set low. We would urge future governments to add Fee and Dividend on top of the CET.

    Our advocacy for an effective carbon price and our efforts to build bipartisanship remain as important as ever. We have much to offer and lots to do!

    Rod Mitchell
    National Coordinator, CCL Australia

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  • What? You don’t think humans are causing climate change? ~ Peter Todd

    By on May 12, 2017

    Written by Peter Todd and posted by Susie Fraser

    I get shocked when people say to me they don’t believe in global climate change or that it’s not caused by humans.

    They often start talking about hoaxes, middle ages warming, ice ages or even more complex stuff.

    You only need six basic facts to know that climate change is real and caused by humans:

    1.The greenhouse warming effect of CO2 is proven by even basic school science experiments.

    2. The only possible source of CO2 to fully explain the current increase is from human causes.

    3. Fossil fuels burnt since the industrial revolution closely matches the level of CO2 increase.

    4. Fossil fuels burned closely matches the reduction in oxygen levels.

    5. The average global temperatures are tracking the CO2 increase. The CO2 increase is steady and temperatures are less steady showing that CO2 is the cause, not the other way around.

    6. The start of CO2 increase coincides with the start of the industrial revolution.

    You may be able to find ways to create doubt on some of these points individually but the likelihood that all six are wrong is ridiculous. (Source Mythbusters – Global Warming & Climate Change Cluedo)

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  • Negative Health Impacts of Climate Change

    By on April 25, 2017

    While talking to parliamentarians with Citizen’s Climate Lobby in March, we were told that the negative health consequences of climate change is an area where there is bipartisan interest and concern.   The following is a summary of the points made in a discussion I led during a recent CCL Australia Zoom Conference.

    There are numerous ways health is affected by climate change.

    1.  Heatwaves

    These are increasing in intensity, frequency and duration.  There has been a doubling of record hot days since 1960.

    They have caused more deaths since 1890 than cyclones, bush fires, earthquakes, floods and severe storms combined.

    There has been a steady increase in mortality in summer compared to winter over the last four decades, suggesting that climate change is already altering health outcomes.

    In the January 2009 Victorian heatwave, there was a 46% increase in emergency call outs on the three hottest days.  Cardiac attacks tripled.  There were 374 excess deaths in the heatwave, a 62% increase compared to the previous year, whereas the fires themselves caused 173 deaths.

    Heat waves cause heat stroke and heat exhaustion as well as worsening in heart, lung and kidney disease.  They possibly cause an increase in preterm birth and underweight babies.  The most vulnerable populations include the elderly, young children, pregnant women and those in financially disadvantaged communities.

    Heatwaves are associated with power failures – lack of air conditioning then exacerbates the risk of adverse health outcomes.  The loss of refrigeration can cause wastage of medicines and vaccines, many of which require refrigeration.  Also there is an increased risk of gastrointestinal diseases due to food spoilage.

    2.  Bush fires

    The risk of bush fires has increased and is expected to continue to increase, especially in south eastern Australia.

    They cause death and illness directly through burns, injuries, dehydration, heat exhaustion and smoke inhalation – this of course includes fire fighters.

    The more indirect effects include damage to hospitals and medical centres.

    The mental health effects are yet another cost – these can be devastating and long standing.  Following the 2003 Canberra bush fires, the was a significant increase in emotional and behavioural problems in children involved.  About 50% displayed some post traumatic stress symptoms.

    3.  Floods and Storm Surges

    There is the direct effect of drowning and injuries.

    Contaminated water caused directly by floods or by damage to sewage treatment infrastructure pose a significant risk of gastrointestinal infectious diseases.

    There is an increase in mosquito borne disease due to an increase in breeding grounds for the mosquitoes.

    Again there is a significant effect on mental health.  The 2011 Queensland floods affected more than 78% of Queensland.  People affected were twice as likely to display mental health symptoms, including  those suggesting PTSD, than individuals who were not affected.

    4.  Infectious Diseases

    The changes in temperature and rainfall mean an increased risk of mosquito borne disease, such and Ross River Fever and Dengue Fever, much further south than was seen in the past.

    5.  Allergies

    Increasing levels and carbon dioxide and higher temperatures result in an increase in production, potency and release of pollen and fungal spores.  Damp conditions following storm surges and floods promote the growth of mould.  These are all triggers for asthma and other allergic conditions.

    Air pollutants such as nitrogen oxides, ground level ozone, particulate matter and sulphur dioxide can aggravate asthma and contribute to the development of asthma in children.

    6.  Air Pollution

    Across Australia, air pollution contributes to about 3000 deaths per year (compared to a road toll of 1209 in 2015).  It is estimated that it causes 6.5 million deaths a year worldwide.

    Burning coal to generate electricity releases many pollutants,including particulate matter, sulphur dioxide, nitrogen oxides, mercury, cadmium and arsenic.  these pollutants contribute to lung cancer, other lung disease such as asthma, heart disease and stroke.

    Urban smog contains a number of pollutants.  One of them is ground level ozone, the levels of which increase on hot, sunny days.  Ozone is a potent airway irritant, triggering asthma.  Just in Sydney, by 2050, the number of hospital admissions caused by ozone pollution is expected to double.

    In conclusion,  as shown in this summary, the effects of climate change on health is myriad and deeply concerning.  As a general practioner, it is my role to try to tackle the root causes of illness.  My efforts with Citizen’s Climate Lobby allow me to attempt to achieve this, with respect to climate change, in the most effective way I can.

    Darshini Heaney

    Member of Citizen’s Climate Lobby
    Member of Doctors for the Environment

    Further Reading:
    Climate and Health in Australia Factsheets, from Doctors for the Environment (DEA), Australia
    DEA Climate and Health in Australia Factsheet – downloadable and very well referenced


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    Citizens' Climate Lobby Australia