CLIMATE CHANGE STATE OF PLAY 2024: we have entered a grim millennia of climate consequences

 

According to the Bureau of Meteorology and CSIRO biennial report, State of the Climate 2024.......

Australia, on average, has warmed by 1.51°C ± 0.23°C since national air temperature records over the land mass of the continent began in 1910. While sea surface temperatures have increased by an average of 1.08°C since 1900.

Australia is not so slowly and very noticeably cooking.

There has been an increase in extreme heat events associated with the warming over land and in the oceans.

Australia’s warmest year on record was 2019, and 8 of the 9 warmest years on record have occurred since 2013.

This is what Australia's collective experience looks like expressed as a graph

State of the Climate 2024, 22 October 2024, p.2

Every decade since 1950 has been warmer than preceding decades. The warming in Australia is consistent with global trends, with the degree of warming similar to the overall average across the world’s land areas.

There has been an increase in extreme fire weather, and a longer fire season, across large parts of Australia since the 1950s. This has resulted in catastrophic bushfires in 1967, 1974-75, 1983, 2006-07, 2009 and 2019-20. Wildfires burning across millions of hectares, changing landscapes and communities, driving many native plant and animal species closer to extinction.

The track record with regard to rainfall has shown that:

Sustained heavy rainfall and associated flooding in much of Australia, particularly the east, is most common during La Niña, as illustrated by the multiple floods that occurred in eastern Australia in 2022. The 11 wettest years on record in eastern Australia were all influenced by La Niña, and many of eastern Australia’s most significant flood years, such as 1974, 2010−2011 and 2021–2022, have occurred during strong La Niña events, although significant flooding can sometimes occur in non-La Niña years.

Global concentrations of all major long-lived greenhouse gases in the atmosphere continue to increase. Global annual mean carbon dioxide (CO₂) concentrations reached 419.2 parts per million (ppm) in 2023 and the CO₂ equivalent (CO₂-e) of all greenhouse gases reached 524 ppm. These are the highest levels on Earth in at least 2 million years.

While global fossil fuel CO₂ emissions, the principal driver of the growth in CO₂ 

concentrations, are continuing to increase.

In Australia the latest Quarterly Update of Australia’s NationalGreenhouse Gas Inventory: March 2024 shows emissions were 440.2 million tonnes of carbon dioxide equivalent (Mt CO₂-e) in the year to March 2024. On a quarterly basis, this means that national emission levels for the March quarter 2024 increased 0.6% (0.6 Mt CO₂-e) in trend terms.

National emissions are preliminarily estimated to be 441 Mt CO₂-e in the year to June 2024.

Actual and trend greenhouse gas emissions have not meaningfully decreased in the last four years according to data collated by the Department of Climate Change, Energy, the Environment and Water.

These inescapable global & national facts mean that Australia's future now holds these scenarios:

Future

In the coming decades, Australia will experience ongoing changes to its weather and climate. The changes are projected to include:

• Continued increase in air temperatures, with more heat extremes and fewer cold extremes.

• Continued decrease, on average, in cool season rainfall across many regions of southern and eastern Australia, which will likely lead to more time in drought.

• More intense short-duration heavy rainfall events even in regions where the average rainfall decreases or stays the same.

• Continued increase in the number of dangerous fire weather days and a longer fire season for much of southern and eastern Australia.

• Further sea level rise and continued warming and acidification of the oceans around Australia.

• Increased and longer-lasting marine heatwaves that will affect marine environments such as kelp forests and increase the likelihood of more frequent and severe bleaching events in coral reefs around Australia, including the Great Barrier Reef and Ningaloo Reef.

• Fewer tropical cyclones, but with higher intensity on average, and greater impacts when they occur

through higher rain rates and higher sea level.

• Reduced average snow depth in alpine regions, but with variations from year to year.

Here in coastal north-east New South Wales the response to our changing climate by successive federal and state governments is: (i) to crowd more urban development onto land that is projected to be amongst the first dry land to experience tidal and/or permanent sea water inundation due to rising sea levels; and (ii) to coat building materials in heat reflecting paint while ignoring the fact that building design is now inadequate due to the fact that the north-east can now expect tropical hurricanes to form offshore on a 1 in 10 year basis.

The world's 8.2 billion people are now ‘Teetering on a planetary tight rope’. Why? Because at successive UN COPs since 2015 the majority of nation participants, political advisors & industry lobbyists have turned the process into a crude, state-sponsored shell game

 

UNITED NATIONS, UN News

24 October 2024 | Climate and Environment

‘Climate crunch time is here,’ new UN report warns

Fossil fuel power plants are one of the largest emitters of the greenhouse gases that cause climate change.

24 October 2024 Climate and Environment

Annual greenhouse gas emissions are at an all-time high, and urgent action must be taken to prevent catastrophic spikes in temperature and avoid the worst impact of climate change, according to a new report released on Thursday by the UN Environment Programme (UNEP).

In short, countries must start curbing emissions immediately, according to the UN Emissions Gap Report 2024.

“Climate crunch time is here,” said UNEP Executive Director Inger Andersen.

“We need global mobilisation on a scale and pace never seen before, starting right now before the next round of climate pledges.”

If not, she warned, the 1.5°C goal to cap rising temperatures set in the Paris Agreement on climate change “will soon be dead, and well below two degrees Celsius will take its place in the intensive care unit”.

Climate goals could evaporate

Launched at the COP16 global biodiversity conference in Cali, Colombia, the report tracks the gap between where global emissions are heading with current country commitments and where they ought to be to limit warming to well below 2°C and pursuing 1.5°C in line with the temperature goals set out in the 2015 Paris Agreement on climate change.

According to the report, the 1.5°C goal will be gone within a few years unless nations collectively commit to cut 42 per cent of annual greenhouse gas emissions by 2030 and 57 per cent by 2035 in the next round of nationally determined contributions and back this up with rapid action.

These self-defined contributions outline steps to reduce emissions and adapt to climate impacts – from drought, flooding and extreme weather events – securing necessary funds and updating plans every five years, the next time being in early 2025 ahead of the COP30 climate talks in Brazil.

‘Teetering on planetary tight rope’

Without dramatic cuts to greenhouse gas emissions, the world could face an inevitable and catastrophic 3.1°C temperature rise, according to the report, which comes at a time when governments are failing to fully deliver on their promises.

UN Secretary-General António Guterres said the emissions gap is not an abstract notion. Indeed, there is a direct link between increasing emissions and increasingly frequent and intense climate disasters.

“We are teetering on a planetary tight rope,” he warned in a video message. “Either leaders bridge the emissions gap or we plunge headlong into climate disaster, with the poorest and most vulnerable suffering the most.

Affordable technologies can help

The COP29 UN Climate Change Conference commencing in Baku, Azerbaijan, in November should serve as a launchpad for a detailed discussion of such new ambitious national plans, he said, saying that the event “starts the clock for countries to deliver new national climate action plans by next year”.

“Governments have agreed to align these plans with 1.5 degrees,” he said.

That means they must drive down all greenhouse gas emissions and cover the whole economy, pushing progress in every sector, he said, urging the largest economies – the G20 members responsible for around 80 per cent of all emissions – to lead in this process.

There is hope, the UN chief stressed.

“Today’s report shows affordable, existing technologies can achieve the emissions reductions we need to 2030 and 2035 to meet the 1.5°C limit, but only with a surge in ambition and support,” he said.

Clean energy can change trajectory

The report shows significant potential to reduce emissions by up to 31 gigatons of CO₂ by 2030, which translates to about 52 per cent of emissions reported in 2023, and by 41 gigatons by 2035, helping to meet the 1.5°C target for both years.

Boosting solar photovoltaic and wind energy usage could contribute 27 per cent of the total reduction in 2030 and 38 per cent by 2035. Additionally, forest conservation could provide around 20 per cent of the necessary reductions in both years.

Other effective strategies include enhancing energy efficiency, electrifying various sectors and transitioning from fossil fuels in buildings, transport and industry, according to the report.

However, the report stated that realising even a fraction of this potential will demand unprecedented international cooperation and a comprehensive approach from governments, focusing on maximising socioeconomic and environmental benefits while minimising trade-offs.

The Emissions Gap Report 2004 titled "No more hot air … please! With a massive gap between rhetoric and reality, countries draft new climate commitments" can be downloaded at

https://wedocs.unep.org/bitstream/handle/20.500.11822/46404/EGR2024.pdf?sequence=3&isAllowed=y

Warning contained on Page 12 of the 2024 report:

Executive summary

All eyes on the next nationally determined contributions

The deadline for countries to submit their next nationally determined contributions (NDCs) with mitigation targets for 2035 is only a few months away, at the time of writing.

The fifteenth Emissions Gap Report has a special focus on what is required from these NDCs to maintain the possibility of achieving the long-term temperature goal of the Paris Agreement of limiting global warming to well below 2°C, while pursuing 1.5°C relative to pre-industrial levels. Its core message is that ambition means nothing without action – unless global emissions in 2030 are brought below the levels implied by existing policies and current NDCs, it will become impossible to reach a pathway that would limit global warming to 1.5°C with no or limited overshoot (>50 per cent chance), and strongly increase the challenge of limiting warming to 2°C (>66 per cent chance). The next NDCs must deliver a quantum leap in ambition in tandem with accelerated mitigation action in this decade.

The magnitude of the challenge is indisputable. At the same time, there are abundant opportunities for accelerating mitigation action alongside achieving pressing development needs and Sustainable Development Goals. Technology developments, particularly in wind and solar energy, continue to exceed expectations, lowering deployment costs and driving their market expansion. The updated assessment of sectoral emission reduction potentials included in this year’s report shows that the techno-economic emission reduction potential based on existing technologies and at costs below US$200 per ton of carbon dioxide equivalent (tCO2e) remains sufficient to bridge the emissions gap in 2030 and 2035. But this will require overcoming formidable policy, governance, institutional and technical barriers as well as an unprecedented increase in the support provided to developing countries along with a redesigning of the international financial architecture. [my yellow highlighting]

From Page 14 of the 2024 report:

Figure ES.2 The landscape of current NDC targets and implementation gaps for the G20 members collectively and individually by 2030, relative to 2019 emissions

Implied emissions trajectories of the G20 members towards net zero show reasons for concern

As at 1 June 2024, 101 parties representing 107 countries and covering approximately 82 per cent of global GHG emissions had adopted net-zero pledges either in law (28 parties), in a policy document such as an NDC or a long-term strategy (56 parties), or in an announcement by a high-level government official (17 parties). All G20 members except Mexico and the African Union (collectively) have set net-zero targets.

Overall, however, limited progress has been made since last year’s assessment on the key indicators of confidence in net-zero implementation, including legal status, the existence and quality of implementation plans and the alignment of near-term emissions trajectories with net-zero targets.

[my yellow highlighting]

On 16 June 2022 Australia submitted an updated version of its 2015 Nationally Determined Contribution (NDC) to the UNFCCC. The update committed Australia to reducing its emissions to 43% below 2005 levels by 2030 and, reaffirmed its commitment to achieve net zero emissions by 2050. NOTE: This is not a commitment to reach absolute zero emissions.

Australia along with other UN member states will be obliged to lodge a new version of its 2022 NDC following COP29 negotiations in November 2024.

BACKGROUND

AUSTRALIA'S ENVIRONMENT 2003 REPORT,

released March 2024, excerpts:

Overview

The year 2023 was one of opposites, with environmental conditions swinging from wet to dry and back.

Globally, climate change accelerated with greenhouse gas emissions accelerating and global warming shattering new records in sea level rise, sea ice loss and temperatures in the oceans and atmosphere.

For Australia, 2023 was the eighth hottest year on record. The year began wet with average temperatures, continuing the La Niña conditions of the previous three years. Northern Australia experienced a wet monsoon season, providing relief after the previous dry years.

Wet conditions gave way to dry and unseasonably warm weather from May to October. River flows, wetlands and water reservoirs all declined from the very high 2022 levels but were still well above average.

Growing conditions were generally very good because of high soil water reserves at the start of the year and the warm and sunny cool season.

The warm and dry winter months did cause an early start of the fire season, as early as August in NSW. An intense fire season was expected but averted when wet conditions returned in November, despite a switch to El Niño climate circulation.

In December, very warm ocean temperatures east of Australia contributed to a cyclone and several storm systems that caused flooding across Queensland and Victoria.

The recovering Great Barrier Reef remained stable, but the impact of the high temperatures, a cyclone and river-borne sediments later in the year is not known yet.

The number of threatened species increased sharply, mostly as a delayed effect of the 2019/20 Black Summer bushfires.

An update to the Threatened Species Index in 2023 revealed continuous and compounding declines for threatened bird populations across Australia.

The greatest threats to Australia’s biodiversity continue to be climate change, invasive species and habitat destruction. Among invasive species, the further spread of cane toads is of significant concern.

Averaged of the year, most environmental indicators declined somewhat from very high values in 2022 but remained well above average, contributing to an overall Environmental Condition Score of 7.5......

Global Change

Globally, CO2 emissions and climate change are accelerating. 2023 saw the highest temperatures in the atmosphere and in the oceans ever recorded, the least sea ice ever observed, and a rapid increase in sea level. Atmospheric CO concentration increased by 2.6 ppm, which is 41% faster than the previous year and 16% faster than the average 2000–2022 growth rate. The rapid increase was due to a combination of ever-increasing fossil fuel emissions and a change to El Niño conditions during 2023. The average CO2 concentration reached 421 ppm, a 33% increase from 1960.

Global average air temperature was the highest on record by a considerable margin. It was 0.32 °C higher than the previous year and 1.18 °C above the 20th century average. The last ten years (2014–2023) all rank as the ten warmest on record.

The maximum ozone hole extent was 2% smaller than the previous year. It was 5% larger than the 2000–2022 average but 13% below the maximum extent observed in 2000. The ozone hole has not shrunk over the last two decades but may have stabilised.

Oceans absorb 93% of excess heat from climate change. Global ocean heat content increased by 4.8% compared to the previous year. Globally, sea surface temperatures were the highest on record in 2023.

The global mean sea level rose by 11.7 mm in 2023; the most rapid rise since 2015. Sea level has increased by 85 mm since 2000 and 101 mm since 1993.

Global Ocean Warming

+4.8% HEAT INCREASED FROM 2022

Sea ice extent was 2% less than the previous year in the Arctic and 8% less around Antarctica, where it broke the record set the previous year. Ice extent on both hemispheres combined was 5.0% less than the previous year, the lowest on record and 9.5% lower than the 2000–2022 average....

The full Australia's Environment 2023 Report can be read and downloaded at

https://www.wenfo.org/aer/wp-content/uploads/2024/03/2023_Australias_Environment_Report_March2024_spreads.pdf

Seven weeks out from the beginning of the Australian Summer meteorologists were predicting "unusually high temperatures from December through to February

 

This is an ABC News article extract on 11 October 2024:

Australia is facing one of the hottest summers on record according to the Bureau of Meteorology's (BOM) weather modelling, which tips well-above-average temperatures across the country.

The forecast for a scorching summer is largely due to ongoing high ocean temperatures surrounding Australia, a persistent feature that has plagued most of the globe since early last year.

The warm seas will not only raise air temperatures but also boost atmospheric moisture levels, swinging the odds to favour frequent storm outbreaks and above-average rain.

Our simmering oceans could also lead to the most active cyclone season in years, with the BOM expecting around 11 named storms in the Australian region, including an increased risk of severe (category three or above) systems.

Of the past six years, the three that were not La Niña periods took the top three spots as Australia's hottest summers on record, all with mean temperatures more than 1.6 degrees Celsius above the long-term average.

This trend suggests this summer will also produce well-above-average temperatures — a prediction supported by seasonal modelling.

The BOM's initial summer forecast, released this week, shows a greater than 80 per cent chance of minimum temperatures in the top 20 per cent of years — which the BOM label "unusually high temperatures"....

So how do conditions look now in Spring 2024?

Australian Bureau of Meteorology (BOM):

Weekly sea surface temperatures

PACIFC OCEAN SEA SURFACE HEAT MAP

Weekly temperature anomalies in the tropical Pacific

For the week ending 13 October 2024, sea surface temperatures (SSTs) were:

• 0.8–2 °C warmer than the 1991–2020 average in the far western and parts of the far eastern equatorial Pacific

• 0.8–2 °C cooler than average in the central equatorial Pacific

• warmer than average across much of the north Pacific, with much of the region surrounding and to the east of Japan more than 3–4 °C warmer than average

• 0.8–2 °C warmer than average around the north-west of Australia's coastline and parts of the Tasman and Coral seas

• 0.4–1.2 °C warmer than average across most of the Maritime Continent.

The Niño indices for the week ending 13 October 2024 are:

Niño3, −0.1 °C; Niño3.4, −0.5 °C; and Niño4, +0.04 °C. The Niño3.4 index reflects historically neutral ENSO conditions.

5-day sub-surface temperatures

For the 5 days ending 13 October 2024, the analysis shows:

• sub-surface temperatures around 1 °C cooler than average in the central equatorial Pacific (between 125 m and 200 m depth) and in the eastern equatorial Pacific (between 50 m and 100 m depth).

• sub-surface temperature anomalies more than 3 °C warmer than average in the shallow eastern equatorial sub-surface (above 50 m depth).

Long-range forecast overview

Issued: 10 October 2024

The long-range forecast for November to January shows:

• Above average rainfall is likely across much of southern and eastern Australia.

• Warmer than average days and nights are likely to very likely across most of Australia.

• Unusually high minimum temperatures are very likely for much of northern and eastern Australia.

Our forecasts have greater accuracy closer to the forecast period. Refer to our weekly updates to follow the evolution of rainfall and temperature patterns as the November to January season approaches.

New South Wales forecast air temperature over land

Max temperature - The chance of above median max temperature for 20 Oct – 2 Nov

The NSW Northern Rivers region is facing an intractable problem - property insurance in the global climate crisis

 

The Climate Risk Group published a report in June 2024 - Going Under: The imperative to act in Australia's high flood risk suburbs

The report looked looked at risk of damage from riverine flooding to residential homes across Australia in 2030 under RCP 8.5 scenario and its analysis covered over 14,739,901 individual addresses and 14,995 suburbs, focussing on homes identified as High Risk Properties (HRP) by 2030 - properties where insurance may become unaffordable or withdrawn completely.

The Climate Group's investigations found:

• By 2030, 588,857 Australian homes are considered to be High Risk Properties: they carry a high risk of flood cover becoming prohibitively expensive or withdrawn, i.e risk becoming uninsurable.

• NSW is by far the most impacted state, with 206,622 individual homes identified as being at high risk of becoming uninsurable by 2030.

• This compares with 382,235 homes in all other states put together.

This report identified nine urban settlement areas in the Northern Rivers region of New South Wales as being at risk in this scenario.

Tweed Heads South, Chinderah, Ballina, West Ballina and Grafton are identified as Black Zone localities. Black Zone Suburbs are suburbs where over 80% of residential properties are at high risk of becoming uninsurable. In these zones, property buy-back and community relocation will have to be considered.

Tweed Heads, Tweed Heads West, Lismore, South Lismore and Yamba are identified as being Red Zone localities. Red Zone Suburbs are suburbs where 50-80% of residential properties are at high risk of becoming uninsurable. With investment in adaptation these zones could still be viable.

On 16 May 2024, the Australian Senate created the Select Committee on the Impact of Climate Risk on Insurance Premiums and Availability. The committee is currently conducting an inquiry into the Impact of Climate Risk on Insurance Premiums and Availability and is to present a final report to parliament by 19 November 2024.

The Insurance Council of Australia has informed this inquiry of the industry's assessment of the national situation:

> Worsening extreme weather events, expansion of development in high-risk areas, growing asset values and higher inflation, particularly in the construction sector, are putting upward pressure on the affordability of insurance in Australia and across markets globally. This is widening the gap between those who can afford insurance and those who can’t, particularly in areas most vulnerable to extreme weather risk.

> To address insurance affordability over the short- to medium-term, it will be critical to continue to strengthen the resilience of communities and businesses so that they can better withstand the disasters Australia is already experiencing. This includes bolstering investment in resilience enhancing infrastructure, strengthening our building stock, and reforming land use planning to improve community safety and affordability when building new homes. After peril risk, the second biggest component of the cost of insurance premiums is taxation; the removal of state insurance taxes will also be an essential reform to provide immediate cost of living relief.

> Over the longer-term, in addition to consistent resilience investment, industry and governments need to continue to tackle the underlying driver of worsening extreme weather, climate change, by maintaining a focus on achieving net zero emissions by 2050.

> The insurance industry, in partnership with governments and regulators, is at the forefront of working to close the protection gap. For example, the Australian Government’s Hazards Insurance Partnership (HIP), focuses on bringing industry and government together to identify the high-risk areas around the country where insurance affordability challenges are growing, and tests and targets the appropriate policy solutions. Insurers are also working with the Australian Prudential Regulation Authority (APRA) to undertake a Climate Vulnerability Assessment focused on the impacts of a warming climate on the availability of general insurance. The ICA and its members have also led key industry initiatives, including releasing an industry-wide climate change roadmap and producing new economic and actuarial analysis focused on the costs of extreme weather, uplifting Australia’s building codes and standards and strengthening state and federal resilience investment.

Northern Rivers newspaper The Echo in an article titled Climate change pushes up insurance, families going uninsured on 8 October 2024:

Financial Rights Legal Centre Senior Policy and Communications Officer Julia Davis told the enquiry, ‘The problem of insurance in a changing climate has reached a point where the market is not going to solve these problems. It is time for government intervention.

‘The repercussions of these events extend beyond financial strain for consumers. The consequences have been deeply personal with individuals facing emotional stress, strained relationships and trauma.’

Ms Davis also said managing insurance claims was ‘nothing short of retraumatising’ for many consumers.

Financial Counsellors Australia National Coordinator for Disaster Recovery, Vicki Staff said her organisation had seen people being quoted over $60,000 per year for insurance.

‘They are now having to find an insurance product that doesn’t fully cover them for the natural perils they are the most at risk of,’ she said.

Widening gap

Insurance Council of Australia Chief Operating Officer Kylie McFarlane told the enquiry, ‘The widening gap between those who can afford insurance and those who can not, especially in areas vulnerable to extreme weather risk, is an issue that we need to address collectively.

‘Insurance prices risk, and the most effective way to reduce pressure on premiums and reduce the protection gap is to mitigate or eliminate those risks.

CLIMATE CHANGE STATE OF PLAY 2024: “Now we are finding that atmospheric CO2 levels are increasing faster than ever. We must recognize that these are clear signals of the damage carbon dioxide pollution is doing to the climate system, and take rapid action to cut fossil fuel use as quickly as we can.”

In a month where Australia is breaking the lowest seasonal temperature records in parts of Australia just weeks after setting maximum temperatures records in another seasonal extreme - while some countries in Europe are either experiencing heatwaves or wildfires at the same time others are experiencing heavy snowfalls or catastrophic flooding - it is no longer being whispered but shouted out that "global warming is now becoming so extreme and non-linear that combined with habitat destruction, pollution, and overkilling of species it threatens collapse in the natural world including human systems within years not decades" [Ben See, climate activist, September 2024].

This is happening because although for decades now global heating of the Earth system has been unequivocal, detected acceleration of Earth heating has never been so sharply evident as it has become in the last two years.

2024 is also the year when evidence suggests that the rapid increase in CO2 concentrations in the atmosphere being recorded may now be independent of the amount of greenhouse gas emissions being released into the atmosphere by human activity. In other words, global warming's effect on the Earth may have passed a tipping point from which there is no return to a pre-industrial era global climate for millennia.

16 September 2024:

"The global temperature according to NASA data. Anyone who is still wondering about #ExtremeWeather and flooding has either missed out on several decades of climate research or deliberately repressed it. #Flood" **

Click on graph to enlarge

Prof. Stefan Rahmstorf, (@rahmstorf) Head of Earth System Analysis, Potsdam Institute for Climate Impact Research & Professor of Physics of the Oceans, Potsdam University

** Text of tweet translated from German to English by Google Translate

U.S. National Oceanic and Atmospheric Administration (NOAA), News Release, 6 June 2024:

During a year of extremes, carbon dioxide levels surge faster than ever

The two-year increase in Keeling Curve peak is the largest on record

June 6, 2024 — Carbon dioxide is accumulating in the atmosphere faster than ever — accelerating on a steep rise to levels far above any experienced during human existence, scientists from NOAA and the Scripps Institution of Oceanography at the University of California San Diego announced today....

From January through April, NOAA and Scripps scientists said CO2 concentrations increased more rapidly than they have in the first four months of any other year. The surge has come even as one highly regarded international report has found that fossil fuel emissions, the main driver of climate change, have plateaued in recent years.

“Over the past year, we’ve experienced the hottest year on record, the hottest ocean temperatures on record and a seemingly endless string of heat waves, droughts, floods, wildfires and storms,” said NOAA Administrator Rick Spinrad, Ph.D. “Now we are finding that atmospheric CO2 levels are increasing faster than ever. We must recognize that these are clear signals of the damage carbon dioxide pollution is doing to the climate system, and take rapid action to cut fossil fuel use as quickly as we can.” ....

CLIMATE CHANGE 2024: Does the climate in the region where you live still feel like the regional climate as you remember it from ten, fifteen, twenty or forty years ago?

 

As seasons of the year in Australia begin to change in character there is some value in establishing what the climate zones across the country's 7.688 million km² landmass are, in order to form personal comparisons that are based on more than childhood memories when attempting to confirm our sense of what Spring, Summer, Autumn and Winter is in 2024.

According to the Australian Bureau of Meteorology (BOM); "Australia is one of only a few countries in the world to span several climate zones".

There is a tropical zone in the north, a subtropical zone across much of our centre and, temperate zones in the south.

This simplified outline of the spatial distribution of these zones is based on meteorological opinion in 2018.

Again according to BOM these are the principal characteristics of these zones:

Tropical zone

Areas near the equator get direct sunlight all year round, meaning that at noon the sun is right overhead. This is called the tropical zone.

When the sunlight hits the surface of the earth or the ocean it warms the air, causing it to rise. The warm air cools as it rises, and the water in the air condenses and falls as rain.

It makes sense then that the tropical zone, which includes places like Cairns and Darwin, is warm and humid most of the year, with a clear wet and dry season as the tropical rain belt shifts south and then north of the equator.

Subtropical zone

If you move further away from the equator, you enter the subtropical zone. This is where the warm rising air air from the tropics falls as dry, cooler air. The sinking air makes for high pressure systems and clear skies at the Earth's surface, so the subtropical zone is fairly dry.

Places like Longreach and Brisbane are considered subtropical. Summers are hot, winters are mild and this zone is where you’ll find most of the world's deserts.

Temperate zone

The next climate zone is the temperate zone. The Earth is round, so sunlight hits these areas on more of an angle then at the equator. The same amount of energy then has to cover a larger area so it’s cooler here than in the tropics.

The Earth is also tilted, so as we move around the sun during the year, temperate zones receive less direct sunlight in winter and more in summer.

Places in the temperate zone—like Hobart and Melbourne—therefore have distinct seasons, with warm, long days in summer, and cold, short days in winter. Most regions in the temperate zone also tend to receive more rainfall in winter than in summer.

Polar zone

The coldest climate zone is the polar zone. Here, the sun is lower in the sky and its rays reach Earth at an even larger angle.

The polar zone is very cold and cold air can't hold much moisture. Some areas in the Arctic and Antarctica are as dry as the subtropical deserts!

So does the climate in the region where you live still feel like the regional climate as you remember it from ten, fifteen, twenty or forty years ago?

Given that by 2023 Australia had a national average surface temp of 1.50°C ± 0.23°C above pre-industrial levels, which has led to an increase in the frequency of extreme heat events.

That 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.

As for April to October rainfall, it 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.

Does it still seem like climate as usual, given in 2023 this country experienced its equal eighth-warmest year on record with the national mean temperature 0.98 °C warmer than the 1961–1990 average. With mean annual maximum and minimum temperatures were above average for all six states and the Northern Territory. While Winter in 2023 was Australia's warmest on record, with the national mean temperature 1.53 °C above the 1961–1990 average and Summer was peppered by frequent low-to-severe intensity heatwave conditions.

It was a year in which during the first quarter, Australia experienced multiple major flood events, mostly across inland and northern regions and then come the August to October period the country experienced its driest three month period on record since 1900.

Surface water storages declined but bounced back to 74% of available national capacity by year's end.

Come 2024 and it seemed that Australia's climate and weather patterns lurched between extremes with Nature trying to find some sort of balance despite the fact that the national land surface temperature still remains at 1.50°C ± 0.23°C above pre-industrial levels with a reasonable chance that it will end the year even higher.

BOM's Seasonal Summary for Australia in Autumn 2024 revealed that a heatwave affected most of south-eastern Australia in the first half of March, with both daytime and night-time temperatures more than 10 °C above the March average, while parts of Western Australia's far west experienced very much above average temperatures in all three autumn months. In May, Perth Metro had 13 consecutive days of at least 25.0 °C, a May record for the combined sites of Perth.

The Summary also stated that the national area-averaged mean temperature for autumn was 0.53 °C above the 1961–1990 average and 0.46 °C above the 1961–1990 autumn area-average mean maximum temperature.

Adding that Area-averaged maximum temperatures were above average for all states, while for the Northern Territory it was 0.88 °C below average and the lowest since 2012.

Mean maximum temperatures were above average to very much above average (in the highest 10% of all autumns since 1910) for Victoria, Tasmania, most of New South Wales and South Australia, a large area in the western part of Western Australia, the Top End of the Northern Territory and coastal and inland areas of central Queensland. Autumn maximum temperatures were the highest on record for parts of Western Australia's west coast, with many stations in these areas having their highest mean maximum temperatures records for autumn.

Mean maximum temperatures were below average to very much below average (in the lowest 10% of all autumns since 1910) for inland areas of the Northern Territory and Western Australia.