Showing posts with label climate change. Show all posts
Showing posts with label climate change. Show all posts

Sunday 10 March 2024

El Niño persists and although it is likely to disappear by May 2024 it may become harder to reliably predict what will follow in the future

 

Australian Bureau of Meteorology (BOM), 5 March 2024


Neutral ENSO likely during autumn



El Niño persists, although a steady weakening trend is evident in its oceanic indicators. Climate models indicate sea surface temperatures in the central tropical Pacific are expected to continue declining and are forecast to return to ENSO-neutral in the southern hemisphere autumn 2024.


Atmospheric indicators are mixed but are consistent with a steadily weakening El Niño. Cloudiness near the equatorial Date Line has decreased over the last fortnight, returning to the climatological average. The 30-day Southern Oscillation Index (SOI) is currently less than -7.0, characteristic of an El Niño state, but indicative of ENSO-neutral conditions over the 60- and 90-day periods. Temporary fluctuations of ENSO atmospheric indicators are common during summer and are not an indication of El Niño strength.


International climate models suggest the central tropical Pacific Ocean will continue to cool in the coming months, with four out of seven climate models indicating the central Pacific is likely to return to neutral El Niño–Southern Oscillation (ENSO) levels by the end of April (i.e., neither El Niño nor La Niña), and all models indicating neutral in May. ENSO predictions made in autumn tend to have lower accuracy than predictions made at other times of the year. This means that current forecasts of the ENSO state beyond May should be used with caution.


Based on the historical record from 1900, around 50% of El Niño events have been followed by an ENSO-neutral year, and 40 to 50% have been followed by La Niña. However, global oceans have warmed significantly over the past 50 years. The oceans have been the warmest on record globally between April 2023 and January 2024. These changes may impact future predictions of ENSO events, if based solely on historical climate variability.


The Indian Ocean Dipole (IOD) is neutral. IOD events are typically unable to form between December and April. This is because the monsoon trough shifts south over the tropical Indian Ocean changing wind patterns and preventing the IOD pattern from forming.


The Southern Annular Mode (SAM) is currently neutral, as of 3 March. Forecasts indicate SAM will remain neutral over the coming fortnight.


The Madden–Julian Oscillation (MJO) is currently in the eastern Indian Ocean. The MJO is forecast to move into the Maritime Continent in the coming days and progress eastwards towards the Western Pacific over the coming fortnight. When the MJO is in the eastern Indian Ocean, increased cloudiness tends to occur over the eastern Indian Ocean and western parts of South East Asia. As the MJO shifts into the Maritime Continent, increased cloudiness tends to occur over parts of the far north of Australia and the islands of South East Asia, Indonesia and Papua New Guinea.


The annual global mean temperature for the 12 months from February 2023 to January 2024 was the highest on record, with Copernicus reporting that it was 1.52 °C above the 1850–1900 pre-industrial average. However, this does not mean that the 1.5 °C target referred to in the Paris Agreement has been exceeded as the magnitude of global warming is assessed using multi-year averages, and this is only one 12-month period.


Australia's climate has warmed by 1.50 ± 0.23 °C between 1910 and 2023, leading to an increase in the frequency of extreme heat events. In recent decades, there has also been a trend towards a greater proportion of rainfall from high intensity, short duration rainfall events, especially across northern Australia during the wet season. April to October rainfall has declined across southern Australia in recent decades, due to a combination of long-term natural variability and changes in atmospheric circulation caused by an increase in greenhouse gas concentrations.


[my yellow highlighting]


Thursday 7 March 2024

Climate Council sounding the alarm on a severe bleaching event unfolding across more than 1,100kms of the Great Barrier Reef from Lizard Island to the Keppel Islands

 

Coral Bleaching, Heron Island
Great Barrier Reef
IMAGE: Divers for Climate, February 2024
Climate Council













Climate pollution is “cooking” the Reef with law reform needed


Climate Council

MEDIA RELEASE TUESDAY 5 MARCH 2024


THE CLIMATE COUNCIL is sounding the alarm on a severe bleaching event unfolding across the Great Barrier Reef, with new vision showing the damage that stretches more than 1100 kilometres from Lizard Island to the Keppel Islands.


Marine heatwaves are bleaching swathes of the Southern Great Barrier reef white, which have brought direct observers to tears. With an ominous marine forecast for the coming weeks, authorities could declare another mass bleaching event.


The Reef, a cherished global icon and home to diverse marine life and a cornerstone of Australian natural heritage, faces repeated and escalating threats from climate pollution, caused by the burning of coal, oil, and gas, including more frequent and severe marine heatwaves.


Climate Council CEO Amanda McKenzie said: “Relentless pollution from coal, oil and gas is Australia’s number one environmental problem and it’s literally cooking the Reef. Our environmental protection laws are outdated and in desperate need of an overhaul to prevent new reef-destroying gas and coal projects.


At least five coal and gas projects have been waved through under our outdated law by the Federal Government since it was elected, and more than 20 other highly polluting proposals are sitting on the Environment Minister's desk right now. These projects will keep being waved through without stronger laws, endangering our Reef, all marine life and the livelihoods of Queenslanders who depend on a healthy, vibrant reef.


Australians expect our national environment law will protect the precious natural environments like the Great Barrier Reef, and the numerous communities that depend upon it - not destroy them. Unless this law is fixed to make climate pollution a core consideration, the Great Barrier Reef will continue to deteriorate before our children’s eyes.”


Climate Councillor Professor Lesley Hughes said: "As ocean temperatures continue to increase, our precious Great Barrier Reef is in grave danger. The composition and diversity of our once mighty Reef has already been changed after repeated marine heatwaves and mass bleaching events driven by the relentless burning of coal, oil and gas. Our focus must be on limiting further harm as much as possible.


Australians understand the Reef is irreplaceable. Many Queensland workers and communities rely directly on it for their livelihoods, and every one of us depends on a healthy ocean. Scientists and tour operators are being brought to tears by what they’re observing.


The Reef can be restored, but it needs at least a decade to recover from a severe bleaching event, and the only way to ensure that can happen is to rapidly reduce climate pollution from coal, oil and gas. The only way to safeguard the Great Barrier Reef as well as everyone and everything that depends on it is to cut climate pollution at the source."


Dr Dean Miller, Climate Council Fellow and reef expert said: "We're seeing the most vulnerable corals to heat stress start bleaching along the length of the Great Barrier Reef, which is alarming.


It's not just about how many corals are bleaching, but that the ones most at risk are suffering. This stress is affecting corals of all sizes, from the largest ones that have survived past bleaching events to the smallest, youngest corals.


If the heat stress continues, we'll see more widespread bleaching affecting a higher diversity of coral species, which is a major concern for the reef's health and ultimately its resilience."


For a closer look at the impacts of climate change on the Great Barrier Reef, explore our collection of recently recorded footage.


The Climate Council is Australia’s leading community-funded climate change communications organisation. We provide authoritative, expert and evidence-based advice on climate change to journalists, policymakers, and the wider Australian community.


For further information, go to: climatecouncil.org.au

Or follow us on social media: facebook.com/climatecouncil and twitter.com/climatecouncil



What is happening on the Great Barrier Reef is not something concerned people on the NSW far north coast can ignore. In addition to the rich marine biodiversity along its est. 2,300km length, the southern section of the Great Barrier Reef as a feeding and breeding ground for edible fish forms part of the sustainability cycle for our regional wild caught fisheries. Keppel Island is less than 700kms from the Clarence Coast fishery, perhaps the largest estuary-ocean fishery in New South Wales. 




Wednesday 6 March 2024

How one e-conveyancing firm ranks NSW coastal erosion, flooding and bushfire risks from 2023-2043

 

In its own words, InfoTrack is a leading SaaS technology innovator and has been the pioneer of e-conveyancing since 2000....From the moment a title search is performed on a property to be listed for sale through to settlement, InfoTrack’s platform transforms plain text into intelligent data that moves seamlessly between the real estate agent, the lawyer, the mortgagee and the seller.


Since November 2023 InfoTrack has been sending out media releases concerning current and expected climate change impacts most often mentioned in coastal zones - erosion, flooding and bushfires:


# From the Harbour to the Hunter, the Northern Beaches tots on the NSW coastal zone the Northern Rivers, the New South Wales suburbs most impacted by coastal erosion have been revealed, along with the 20 locations to be worst affected in the future;


# Rounding out the top five are Northern New South Wales’ Moree at number two, the Central West’s Forbes at number three, Walgett in the State’s North at number four, and the Riverina’s Moama at five.

Popular tourist locations also feature – the beautiful coastal town of Yamba, a mecca with holidaymakers, is named at number eight, Grafton in the Northern Rivers comes in at number 13, with bustling Port Macquarie, on the mid north coast, at number 15. The Central Western town of Dubbo sneaks in at number 20 on the list.....

The data and models use high-resolution topographical data, detailed land cover information, and advanced weather models to accurately simulate flood depths and extents,” Mr Montagnani said.

This comprehensive evaluation, provided by Royal HaskoningDHV’s division Twinn, encompasses various scenarios, including surface water, river, and tidal flooding, and integrates state-of-the-art climate models to provide flood risk assessments in the context of climate change.”

Interestingly, all the suburbs listed as most at risk now, remain the most at-risk decades from now.

Grafton is slightly more at risk of flooding in the future, going from 13 on the list of suburbs affected by flooding now, to 12 on the list of suburbs most impacted in 30 years, effectively swapping places with Condobolin; and


# Off the back of sweltering temperatures across New South Wales, new data has been released naming the top 20 suburbs most impacted by bushfires now, along with the locations to be most affected in the future.

Blue Mountains National Park comes in at number one currently, with Colo Vale in the Southern Highlands, and Booligal in the Riverina rounding out the top three, according to Groundsure ClimateIndex™ reports, available through InfoTrack.

Also making the Top 20 are popular Blue Mountains suburbs Kurrajong Heights (number 6), Blackheath (number 14), and Bilpin (number 13), and the Hawkesbury’s Lower Portland (number 19).


Northern NSW towns and villages feature in all three tables.

*click on all tables to enlarge*


Erosion


IMAGE: InfoTrack in Nationwide News, 14.11.23





Flooding


IMAGE: InfoTrack





Bushfires


IMAGE: InfoTrack







Prospective homebuyers can search a property address via InfoTrackGO to purchase a Groundsure ClimateIndex™ for that residence.


Tuesday 5 March 2024

Climate Change Australia State of Play 2024: will there ever be climate resilient housing for the poor and disadvantaged?

 


IMAGE: The Guardian, 9 December 2023






Australian Council of Social Service (ACOSS), "ACOSS Summer Heat Survey 2024", 1 March 2024, excerpts:


* Introduction


Summers are becoming hotter with climate change. In fact, the last nine years were the world’s hottest on record, with 2023 being the hottest year to date. Australia is experiencing more very hot days and heatwaves, and Bureau of Meteorology data forecasts more days where the national daily average is over 40 degrees. For people in remote areas and places like central and northern Australia, high temperatures are already common and daily temperatures reach 35 degrees for over half the year.


Severely hot days and heatwaves affect people experiencing financial and social disadvantage worst because they have fewer resources and choices to protect themselves from extreme heat. This is an urgent and critical public health problem. Heatwaves cause more deaths than all other extreme weather events combined. In Australia, there were an estimated 36,000 deaths associated with heat between 2006 and 2017. A lack of access to energy-efficient homes is often a primary factor in these deaths.


People experiencing financial and social disadvantage are vulnerable to high temperatures because they often live in homes that are poorly insulated, with no or limited shading; and no air conditioning or fans to help cool indoor temperatures. Even if the home has air conditioning and/or fans, rising energy costs mean that people on low incomes often cannot afford to run them. They are also less likely to have rooftop solar, which would significantly reduce their energy bills.


Further, people in rental properties are not able to make changes in their home that could make them more liveable, healthy and safe. Minimum rental standards could address this problem by placing requirements on landlords to ensure their property protects tenants against heat or cold. For example, the ACT requires landlords to have ceiling insulation and Victoria is implementing minimal rental standards.


ACOSS conducted a public, online Heat Survey over the 2023-24 summer to explore the intersection between high temperatures, energy performance of homes, energy costs and income. The data is gathered to advocate for support for people experiencing financial and social disadvantage to secure cooler, healthier and more climate-resilient homes, putting people with the least at the centre of government policy and planning.


The survey gives us valuable insight into how severely high heat affects people’s physical and mental health, their wellbeing and activity when they cannot cool their homes. The survey highlights how seriously poverty and poor energy-performing homes can reduce people’s resilience and capacity to cope with debilitating hot weather.


The ACOSS Heat Survey was open from 1 December 2023 to 28 January 2024. It was made available online via the survey tool, TypeformTM.



* Key findings


Exposure to high heat is a major threat to human health. More people die in Australia from heatwaves than all other extreme events combined. With climate change, Australia is becoming hotter. Very hot days and heatwaves are becoming more common. People experiencing financial and social disadvantage are worst impacted by these events.


Those worst affected experience a combination of:


homes with poor energy performance;

high energy prices;

low incomes; and

health conditions.


To track the intersection between housing, energy costs, heat, and people experiencing financial and social disadvantage, ACOSS conducted a public, online Heat Survey over the summer months, from December 2023 to January 2024. We received 1007 responses from people across the country, including: 66.1% receiving income support; 19.2% in social housing; 36.1% in private rental; 6.4% First Nations respondents. Additionally, 62.7% reported they or someone in their household has a disability or chronic health condition.


The survey found the majority of 1007 people surveyed (80.4%) said their homes get too hot. This was often to do with being in homes with low energy efficiency (e.g., no insulation or shading, dark roofing, no eaves).


More than half (56.7%) could not cool their home because:


they do not have air conditioners or fans, or have them but they are broken, or have them only in part of the home or they are ineffective in cooling the home; or

if they had functioning air conditioners and or fans, they could not afford to run them.


People most likely to struggle to cool their homes were:


people in social housing (78.3%) or private rental (65.7%) with limited control to modify their home or access working efficient air conditioners to better deal with extreme temperatures;

people receiving income support (60.8%) with limited resources to modify their homes, afford air-conditioning or fans, or afford the running costs to cool their home;

and

First Nations people (71.9%), two thirds of whom were in social or private rental, and more than three-quarters of whom were receiving income support.


Exposure to high temperatures in the home has a range of serious negative impacts on household members. Respondents to the survey reported:


Negative physical and mental health impacts, making them unwell (80.5% of all 1007 respondents; 94% of First Nations respondents). For many, the heat seriously aggravated existing chronic health conditions or disabilities.

Having to seek medical attention for heat stress (14% of all respondents; 25% of First Nations respondents).

Difficulty sleeping (94% of all respondents; 98% of First Nations respondents), reduced productivity for work and study, and raised tensions in the home.

Avoiding everyday household activities due to the heat (like housework and cooking).


While medical and government advice often is to leave home to go to a cooler place during very hot weather, this is not always easy. Most people (90.5%) reported that they face mobility, cost and other barriers to doing so.


Many people reported challenges affording their energy bills which meant they couldn’t cool their home and/or afford other essentials:


59.8% reported finding it increasingly difficult to pay their energy bills, which affected their capacity to cool their homes.

Many reported that high energy bills made it difficult to pay for essentials like food (46.7%), medicine (41.4%) or housing (34%).


First Nations respondents were even more likely to be struggling to pay for essentials such as energy and other bills (86%), food (75%), medicine (63%) and housing (58%).


A quarter of all 1007 people surveyed (25.8%) were currently in energy debt with their retailer or believed they would go into energy debt because they could not afford their next energy bill. People receiving income support (69.4%) and First Nations people (55%) were more likely to say they had an energy debt or that they considered it to be imminent.


We note that while the people surveyed are currently housed, extremes of temperature present more severe health risks from exposure and threats to life itself to people living on the streets or sleeping rough.


Findings from the ACOSS 2024 Heat Survey raise similar concerns to the previous ACOSS 2023 Heat Survey Report and Sweltering Cities’ 2021 and 2022 Summer Survey Reports.


However, a hotter summer in 2023/24, coupled with rising costs for energy, housing, food and other essentials were reflected in people’s comments. There was a clear level of distress amongst people surveyed about the growing challenge to reduce the impacts of

heat while affording energy bills and avoiding – or compounding existing - energy debt.


For people experiencing financial and social disadvantage, especially those living with disability or a health condition, the situation of hot homes that cannot be cooled remains untenable, putting lives at risk. The situation facing First Nations people surveyed is much worse on almost every measure. Therefore, prioritising this report’s recommendations for First Nations communities is essential.


Almost all 1007 people who completed the 2024 Heat Survey (96.5%) called on governments to do more to improve homes to be more resilient to extreme heat (and cold) and to support people to be able to afford energy bills and other essentials....


Read the full 30 page report and recommendations at:

https://www.acoss.org.au/wp-content/uploads/2024/03/ACOSSHeatSurveyReport2024.pdf



Friday 1 March 2024

Only two of the seven local government councils in the NSW Northern Rivers regions have made a genuine effort to divest themselves of fossil fuel industry investments

 

ECHO, 28 February 2024:



Byron Shire Council investments in fossil fuel projects as of Jan 2024 PIC Byron Shire Council


Byron Shire Council investments in projects linked to fossil fuel production decreased significantly after the NSW Treasury Corporation (TCorp) relaxed rules last year.


Investment reports included in last week’s agenda for the council’s ordinary monthly meeting showed the council had 56% of its investment funds lodged with fossil fuel aligned projects by the end of January 2024.


The figure was a decrease compared to 71% at the end of December 2023 and 85% at the end of the 2022-2023 financial year.


Staff credited the removal of a state covenant requiring local governments to invest TCorp loans mostly in institutions with A+ credit ratings or stronger.


Institutions offering investments in the ‘ethical’ area still mainly had lower credit ratings of BBB, or weren’t rated at all, staff said, citing credit unions as an example.


Staff noted the council’s diversified approach to investment was aimed at achieving short, medium, and long-term results.


Investment was regulated by TCorp, which until late last year effectively forced NSW local governments to bank at least a quarter of their low interest TCorp loans in A rated institutions or higher.


The council wasn’t allowed at the time to invest any more than 40% of the loans in A- rated institutions, 30% in BBB+ rated institutions and 5% in institutions rated BBB- and below.


Credit ratings allowed ranged from BBB- and below, or not rated, to AAA, with councils also encouraged to invest in TCorp itself.


End of financial year 2022-2023 figures from the council showed of nearly $65 million invested at the time, 85% was helping support fossil fuel aligned projects via various bonds, term deposits and other accounts..... [my yellow highlighting]


Read the full article here.


At the end of the 2022-23 financial year Richmond Valley Council had a cash held in banks & investment portfolio of $90.668 million. Of which $48.087 million or 53 per cent of the total was invested with financial institutions which do not invest in or finance the fossil fuel industry.


As of 30 June 2023 Clarence Valley Council investment portfolio stood at $156.357 million. 

Of which only $12 million is invested with financial institutions which do not invest in or finance the fossil fuel industry. Representing a paltry 7.67 per cent of council's investments. 

At the ordinary monthly meeting of 25 July 2023 all nine councillors voted to simply note Clarence Valley Council's investment position. Which appears to indicate that this local government is not overly interested in living up to rhetoric expressed in the past.


On 30 June 2023 Ballina Shire Council's investment portfolio stood at $104.300 million, of which only $8 million or 7.67 per cent was invested with financial institutions which do not invest in or finance the fossil fuel industry. As councillors there also voted to note the report without comment, there is no indication that council will be increasing its green investments anytime soon.


Tweed Shire Council valued its investment portfolio at $431.958 as at 30 June 2023. None of the investments listed were identified as being invested with financial institutions which do not invest in or finance the fossil fuel industry.


Lismore City Council listed the face value of its investment portfolio as $133.719 million. Council also had approximately $1.9 million held in various bank accounts which were deemed as transactional accounts and are not included in the investment portfolio. Council takes care to note that it holds no funds in fossil free investments or 0 per cent.


Finally, Kyogle Council published its 2022-23 financial statement in December 2023 and did not identify investments as a single line item, so nothing was to be gleaned as to what if any money it had invested with financial institutions which do not invest in or finance the fossil fuel industry.


Tuesday 20 February 2024

Australian Bureau of Meteorology partners with European Centre to ensure more eyes on Earth

 



Copernicus Sentinel Satellites providing all weather, day & night Earth-observation data to feed into a range of services for monitoring weather, land & ocean environments and supporting civil security activities. IMAGE: The European Space Agency



Australian Bureau of Meteorology, media release, 16 February 2024:


The Bureau of Meteorology (the Bureau) has signed an agreement with the European Centre for Medium-Range Weather Forecasts (ECMWF) on collaboration, data and knowledge sharing and capability exchange programs.


A five-year strategic relationship agreement was signed this week by the Bureau's CEO and Director, Dr Andrew Johnson, and the Centre's Director-General, Dr Florence Rabier.


The Bureau has been invited to work with ECMWF as part of the Copernicus Climate Change Service. Copernicus is the Earth observation component of the European Union’s space programme and includes satellite and in situ observations combined with expert modelling to provide services such as the Climate Change Service implemented by ECMWF.


Under this agreement we are adding long-range global forecasts from the Bureau of Meteorology’s Australian Community Climate and Earth System Simulator – also known as ACCESS – to the Copernicus multi-model global ensemble. ACCESS will join other world-leading models, demonstrating the importance of scientific collaboration and of Australia’s contribution to the international community," Dr Rabier said.


This is an important ongoing partnership for ECMWF, the benefits of which will be felt worldwide in the ensemble forecasts produced. It will also lead to further improvements in weather and climate modelling and research conducted in Europe and Australia.”


ACCESS is the Bureau's extended and long-range forecast system. It is a state-of-the-art dynamical (physics-based) forecast modelling system, which uses ocean, atmosphere, ice and land observations to initiate forecasts for the season ahead.


There are eight contributors to the ECMWF Copernicus multi-system global ensemble and the addition of the Bureau's ACCESS forecasts brings this total to nine.


"This new agreement enables the Bureau to access more comprehensive data from some of the world’s best forecast models to support and improve its own services," Dr Johnson said.


"It also provides more opportunities for joint research projects exploring weather and climate impacts in the southern hemisphere and around the globe."


"This is a huge accomplishment for the Bureau and Australia. The benefits of this partnership will lead to future improvements in Australian weather and climate products and services for the benefit of the Australian community."


The European Centre for Medium-Range Weather Forecasts (ECMWF) is an independent intergovernmental organisation supported by 35 states. It is both a research institute and a 24/7 operational service, producing and disseminating numerical weather predictions to its Member States. The ECMWF was established in 1975 and its purpose – then as now – was to pool Europe's meteorological resources to produce accurate climate data and medium-range forecasts - ECMWF |Advancing global NWP through international collaboration. It implements the Copernicus Climate Change Service and the Copernicus Atmosphere Monitoring Service on behalf of the European Commission. Homepage | Copernicus.


The Bureau of Meteorology is Australia's national weather, climate, oceans, water and space weather agency. Its expertise and services assist Australians in dealing with the harsh realities of their natural environment, including drought, floods, fires, storms, tsunami and tropical cyclones. Through regular forecasts, warnings, monitoring and advice spanning the Australian region and Antarctic territory, the Bureau provides one of the most fundamental and widely used services of government - Australia's official weather forecasts & weather radar - Bureau of Meteorology (bom.gov.au)


Monday 19 February 2024

That Australia faces rising air, land & sea surface temperatures is a situation that can no longer be denied and yet federal, state and local governments are not fully addressing the thermal mass of subdivision & individual residential dwelling design

 

The fact that ambient air temperature, lad surface and sea surface temperatures are rising across the Australian continent can no longer be denied.


GRAPH: Australian Bureau of Meteorology






In New South Wales generally average maximum temperatures in the month of January 2024 ranged from around 24°C to 36-39°C, spiked by days on end of heatwave temperatures which often broke temperature records for individual localities.


MAPPING:  Australian Bureau of Meteorology






In the north-east coastal zone of the state the minimum air temperature was 1°C higher and maximum air temperature 1-2°C higher than they were between 1981-2010.


In January the highest Northern Rivers region minimum & maximum recorded daily temperature range was:


Evans Head 24.838°C

Grafton 24.537.6°C

Yamba 25.637.2°C

Murwillumbah 27.1—36.2°C

Casino 27.1—36.2°C

Lismore 24.5—35.6°C

Tabulam 23.0—34.9°C

Byron Bay 25.6—32.7°C

Ballina 24.934.2°C

Note: These are the nine official Bureau of Meteorology weather stations in the Northern Rivers region.



Yet despite all this new subdivision schemes and housing designs are paying little more than lip service to sustainability and mitigating the thermal load of both the internal road networks of these subdivisions or the collective & individual loads of dwelling contained there in.


Apparently, multi-dwelling structures that increasing look like a collection of boxes are skating through BASIX requirements on the presumption that each individual box within these boxes will be fully air conditioned at some point before occupation or that if ceiling fans are fitted to some of the rooms then this will mitigate heat.


An assumption which:

(i) takes no account of the increasing stress air conditioning places on a household's cost of living. Because the price per kilowatt hour & associated charges of residential electricity supply continues to rise and commonly these multiple dwelling boxes are not built with any rooftop solar power grid to mitigate cost;

(ii) completely ignores the increasing risk of destructive storms causing levels of damage to power supply infrastructure that cuts power supply to both collections of streets or entire towns for days/weeks at a time. As occurred in heatwave conditions in 2024; and

(iii) appears to leave the thermal load of closely clustered internal roads out of the equation completely.


I expect the latest collection of boxes being considered by Clarence Valley Council will also get the nod because I have yet to see this local government apply the full suite of climate change policies to every development application before deciding consent. The heat footprint of an application rarely rates a mention in Council-in-the-Chamber debates or elicits questions to senior staff attending. Neither are there many mentions of the heat island affect caused by new roads, pavements and driveways. Nor does the wind resistance factor of a proposed building arise - and given the entire Clarence Coast is now in a cyclone risk zone that borders on the negligent when assessing new development applications.


Artists impression of street view of 6 Yamba Road, Yamba proposed subdivision. IMAGE: BDA


Set out below are some basic facts about how the freestanding houses, town houses, duplexes, units and flats we live in attract and retain heat.


Australian Government, Your Home, retrieved 19 February 2024:


Passive Design


What is thermal mass?

In simple terms, thermal mass is the ability of a material to absorb, store and release heat. Materials such as concrete, bricks and tiles absorb and store heat. They are therefore said to have high thermal mass. Materials such as timber and cloth do not absorb and store heat and are said to have low thermal mass.


In considering thermal mass, you will also need to consider thermal lag. Thermal lag is the rate at which heat is absorbed and released by a material. Materials with long thermal lag times (for example, brick and concrete) will absorb and release heat slowly; materials with short thermal lag times (for example, steel) will absorb and release heat quickly.


Thermal mass


Thermal mass, or the ability to store heat, is also known as volumetric heat capacity (VHC). VHC is calculated by multiplying the specific heat capacity by the density of a material:


  • Specific heat capacity is the amount of energy required to raise the temperature of 1kg of a material by 1°C.

  • Density is the weight per unit volume of a material (ie how much a cubic metre the material weighs).


The higher the VHC, the higher the thermal mass.


Water has the highest VHC of any common material. The following table shows that it takes 4186 kilojoules (kJ) of energy to raise the temperature of 1 cubic metre of water by 1°C, whereas it takes only 2060kJ to raise the temperature of an equal volume of concrete by the same amount. In other words, water has around twice the heat storage capacity of concrete. The VHC of rock usually ranges between brick and concrete, depending on density. Most common building materials with high VHC also tend to be quite conductive, making them poor insulators.






Thermal lag


How fast heat is absorbed and released by uninsulated material is referred to as thermal lag. It is influenced by:


  • heat capacity of the material

  • conductivity of the material

  • difference in temperature (known as the temperature differential or ΔT) between each face of the material

  • thickness of the material

  • surface area of the material

  • texture, colour and surface coatings (for example, dark, matte or textured surfaces absorb and re-radiate more energy than light, smooth, reflective surfaces)

  • exposure of the material to air movement and air speed.


To be effective in most climates, thermal mass should be able to absorb and re-radiate close to its full heat storage capacity in a single day–night (diurnal) cycle.


In moderate climates, a 12-hour lag cycle is ideal. In colder climates subject to long cloudy periods, lags of up to 7 days can be useful, providing there is enough solar exposed glazing to ‘charge’ the thermal mass in sunny weather.


Embodied energy


Some high thermal mass materials, such as concrete, cement-stabilised rammed earth, and brick, have high embodied energy when used in the quantities required. This highlights the importance of using such construction only where it delivers a clear thermal benefit. When used appropriately, the savings in heating and cooling energy from the thermal mass can outweigh the cost of its embodied energy over the lifetime of the building. Consideration should be given to using high thermal mass materials with lower embodied energy, such as water, adobe or recycled brick.


Why is thermal mass important?


When used correctly, materials with high thermal mass can significantly increase comfort and reduce energy use in your home. Thermal mass acts as a thermal battery to moderate internal temperatures by averaging out day−night (diurnal) extremes.


In winter, thermal mass can absorb heat during the day from direct sunlight. It re-radiates this warmth back into the home throughout the night.

In summer, thermal mass can be used to keep the home cool. If the sun is blocked from reaching the mass (for example, with shading), the mass will instead absorb warmth from inside the home. You can then allow cool breezes and convection currents to pass over the thermal mass overnight to draw out the stored energy.


Conversely, poor use of thermal mass can reduce comfort and increase energy use. Inappropriate thermal mass can absorb all the heat you produce on a winter night or radiate heat to you all night as you try to sleep during a summer heatwave.....