Climate Change - Assessment Report - Australia's difficult future unless increased action is taken

Is this Australia’s climate wake-up call? Official report reveals a hotter, harder future if we don’t act now

Andrew B. Watkins, Monash University; Lucas Walsh, Monash University, and Tas van Ommen, University of Tasmania

Climate shocks threaten to devastate communities, overwhelm emergency services and strain health, housing, food and energy systems according to a federal government assessment released today.

The report, Australia’s first National Climate Risk Assessment, confirms the devastating consequences of climate change have arrived. It also reveals the worsening effects of extreme heat, fires, floods, droughts, marine heatwaves and coastal inundation in coming decades.

The sobering assessment is a major step forward in Australia’s understanding of who and what is in harm’s way from climate change. It is also a national call to action. The sooner Australia mitigates and adapts, the safer and more resilient we will be.

Australia’s climate risk revealed

The assessment involved more than 250 climate experts, including the authors of this article, and contributions from more than 2,000 specialists. It was also informed by data and modelling from the Australian Climate Service, CSIRO, Bureau of Meteorology, the Australia Bureau of Statistics and Geoscience Australia, among other major institutions.

The report provides the vital evidence base to inform Australia’s first National Adaptation Plan, also released today.

Earth has already warmed by 1.2°C since pre-industrial times, and remains on track for 2.7°C by the end of the century if no action is taken. The assessment considers the impacts on Australia at 1.5°C, 2°C and 3°C of global warming.

The risks to Australia are assessed under eight key systems, as we outline below.

Graphic showing climate risks to Australia’s key systems. National Climate Risk Assessment

1. Health and social support

Climate hazards will severely impact physical and mental health. The most vulnerable communities include Aboriginal and Torres Strait Islander people, the elderly, the very young and those with pre-existing health conditions, as well as outdoor workers.

At 3°C global warming, heat-related deaths increase by 444% for Sydney and 423% for Darwin, compared to current conditions.

Deaths from increased disease transmission are expected to rise. Vector borne diseases such as malaria and dengue fever may spread in the tropics.

Attracting health care workers to remote areas will be increasingly hard, and services will be strained by rising demand and disrupted supply chains.

2. Communities

Coastal, regional and remote communities face very high to severe risk.

More than 1.5 million people in coastal communities could be exposed to sea level rise by 2050, increasing to more than 3 million people by 2090.

Communities within 10km of soft shorelines will be especially vulnerable to erosion, inundation and infrastructure damage.

Extreme weather events – including heatwaves, bushfires, flooding and tropical cyclones – will intensify safety and security risks, especially in Northern Australia.

Compounding hazards are expected to erode community resilience and social cohesion. Water supplies in many areas will be threatened. Economic costs will escalate and people may be forced to migrate away from some areas.

3. Defence and national security

Climate risk to defence and national security is expected to be very high to severe by 2050. This system includes emergency management and volunteers.

Defence, emergency and security services will be increasingly stretched when hazards occur concurrently or consecutively.

If the Australian Defence Force continues to be asked to respond to domestic disasters, it will detract from its primary objective of defending Australia. At the same time, climate impacts will cause instability in our region and beyond.

Repeated disasters and social disruptions are likely to erode volunteer capacity. Increasing demands on emergency management personnel and volunteers will intensify and may affect their physical and mental wellbeing.

4. Economy and finance

Risks to the economy, trade and finance is expected to be very high by 2050. Projected disaster costs could total A$40.3 billion every year by 2050, even at 1.5°C.

Losses in labour productivity due to climate and weather extremes could reduce economic output by up to $423 billion by 2063. Between 700,000 and 2.7 million working days would be lost to heatwaves each year by 2061.

Extreme weather will lead to property damage and loss of homes, particularly in coastal areas. Loss on property values are estimated to reach A$611 billion by 2050. Insurance may become unaffordable in exposed areas, putting many financially vulnerable people at further risk.

Coupled with increased prices for essential goods, living costs will rise, straining household budgets.

The economy could experience financial shocks, leading to broader economic impacts which especially affect disadvantaged communities.

5. Natural environment

Risk to the natural environment is expected to be severe by 2050.

Important ecosystems and species will be lost by the middle of the century. At 3°C warming, species will be forced to move, adapt to the new conditions or die out. Some 40% to 70% of native plant species are at risk.

Ocean heatwaves and rising acidity, as well as changes to ocean currents, will massively alter the marine ecosystems around Australia and Antarctica. Coral bleaching in the east and west will occur more frequently and recovery will take longer.

Ocean warming and acidification also degrades macroalgae forests (such as kelp) and seagrasses. Freshwater ecosystems will be further strained by rainfall changes and more frequent droughts.

Loss of biodiversity will threaten food security, cultural values and public health. The changes will disrupt the cultural practices of Aboriginal and Torres Strait Islander peoples and their connection to Country.

6. Infrastructure and the built environment

By 2050, the climate risk to infrastructure and built environment is expected to be high or very high.

Climate risks will push some infrastructure beyond its engineering limits, causing disruption, damage and in some cases, destruction. This will interrupt businesses and households across multiple states.

Extreme heat and fires, as well as storms and winds, will increasingly threaten energy infrastructure, potentially causing severe and prolonged disruptions.

Transport and supply chains will be hit. Water infrastructure will be threatened by both drought and extreme rainfall. Telecommunications infrastructure will remain at high risk, particularly in coastal areas.

The number of houses at high risk may double by 2100. Modelling of extreme wind shows increasing housing stock loss in coastal and hinterland regions, particularly in Queensland, Western Australia and the Northern Territory.

7. Primary industries and food systems

By 2050, risks to the primary industries and food systems will be high to very high. This increases food security risks nationwide.

Variable rainfall and extreme heat will challenge agriculture, reducing soil moisture and crop yields. Farming communities will face water security threats.

Hotter climates and increased fire-weather risks threaten forestry operations. Fisheries and aquaculture are likely to decline in productivity due to increased marine temperatures, ocean acidity and storm activity.

The livestock sector will face increased heat stress across a greater area. At 3ºC warming, more than 61% of Australia will experience at least 150 days a year above the heat-stress threshold for European beef cattle.

Biosecurity pressures will increase. Rainfall changes and hotter temperatures are expected to help spread of pests and diseases.

8. Aboriginal and Torres Strait Islander Peoples

As part of the assessment, Aboriginal and Torres Strait Islander peoples identified seven additional nationally significant climate risks:

• self-determination
• land, sea and Country
• cultural knowledges
• health, wellbeing and identity
• economic participation and social and cultural economic development
• water and food security
• remote and rural communities.

As the report notes, climate change is likely to disproportionately impact Aboriginal and Torres Strait Islander peoples in terms of ways of life, culture, health and wellbeing as well as food and water security and livelihoods. It also notes Aboriginal and Torres Strait Islander peoples “have experience, knowledge and practices that can support adaptation to climate change”.

Doing more. Doing better.

The assessment poses hard questions about how climate change will affect every system vital to Australia.

Ideally, such an assessment would be carried out every five years and be mandated by legislation.

Future assessments should comprehensively examine global impacts and their flow-ons to Australia. As the COVID pandemic showed, Australia is part of a global system when it comes to human health and supply chains. Defence, trade and finance all are international by nature. And climate change refugees from the South Pacific are already arriving.

The assessment makes clear that current efforts to curb and adapt to climate change will not prevent significant harm to Australia and our way of life. We must do better – and do it quickly.

Young people, and unborn generations, can and will hold us all to account on our progress from today.

Andrew B. Watkins, Associate Research Scientist in Climate Science, Monash University; Lucas Walsh, Professor of Education Policy and Practice, Youth Studies, Monash University, and Tas van Ommen, Adjunct Professor in Climate Science, University of Tasmania

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Climate Change - Heatwaves lead to faster ageing

                                                                                             Shutterstock

The invisible effects of climate change via the increasing number of heat waves are more profound than many people may have imagined from trends over the past couple of decades. Heat waves in general are a well known health risk through the effects of dehydration, loss of body mass and organ stress. The evidence is now building that heat waves increase the ageing process itself.

A long-term study of 24,922 people in Taiwan, published in Nature Climate Change in August this year, has found that a moderate increase in cumulative heatwave exposure increases a person's biological age "...to an extent comparable to regular smoking or alcohol consumption. The more extreme-heat events that people were exposed to, the more their organs aged".

To reach this conclusion, the researchers analysed data from medical examinations between the years 2008 to 2022 during which time Taiwan experienced around 30 heatwaves. The definition of 'heatwave' applied was a period of elevated temperature over several days.  The results from several medical tests including assessments of liver, lung, kidney function, blood pressure and inflammation was used to calculate biological age. 

The results from the study found that the more extreme-heat events that people experienced the faster the ageing process that occured. For every extra 1.3°C exposure for a participant, around 0.023 to 0.031 years on average was added to their biological clock.  While the initial numbers may appear small, over time with accumulated effects and across populations, the impact on public health would be meaningful and costly. As increasing heat is a key effect from climate change, this latest research demonstrates the wide range of implications for life on this planet.

Environment - Climate Change - Extreme weather and declining tropical birdlife

70 years of data show extreme heat is already wiping out tropical bird populations

DeAgostini/Getty Images

James Watson, The University of Queensland; Maximilian Kotz, Barcelona Supercomputing Center-Centro Nacional de Supercomputación (BSC-CNS), and Tatsuya Amano, The University of Queensland

Human-driven climate change threatens many species, including birds. Most studies on this topic focus on long-term climate trends, such as gradual rises in average temperatures or shifts in rainfall patterns. But extreme weather events are becoming more common and intense, so they warrant further attention.

Our new research shows extreme heat is having a particularly severe effect on tropical birds. We found increased exposure to extreme heat has reduced bird populations in tropical regions by 25–38% since 1950.

This is not just a temporary dip – it’s a long-term, cumulative effect that continues to build as the planet warms.

Our research helps explain why bird numbers are falling even in wild places relatively untouched by humans, such as some very remote protected tropical forests. It underscores the urgent need to reduce greenhouse gas emissions, to conserve the remaining biodiversity.

Digging into huge global datasets

We analysed data from long-term monitoring of more than 3,000 bird populations worldwide between 1950 and 2020. This dataset captures more than 90,000 scientific observations.

Although there are some gaps, the dataset offers an unmatched view of how bird populations have changed over time. Some parts of the world such as western Europe and North America were better represented than others, but all continents were covered.

We matched this bird data with detailed daily weather records from a global climate database that stretches back to 1940. This allowed us to track how bird populations responded to specific changes in daily temperatures and rainfall, including extreme heat.

We also looked at average yearly temperatures, total annual rainfall, and episodes of unusually heavy rainfall.

Using another dataset that reflects human industrial activity over time, we accounted for human pressures such as land development and human population density.

By combining all these sources of data, we created computer models to evaluate how climate factors and human impacts influence bird population growth.

Our research confirmed the work of other climate scientists showing extreme heat events have increased dramatically over the past 70 years, especially near the equator.

Birds in tropical regions are now experiencing dangerously hot days about ten times more often than they did in the past.

Tropical birds have experienced a 10-fold increase in exposure to extreme heat over the past 60 years. Kotz, M. et al. (2025) Nature Ecology & Evolution

What we found: extreme heat is the biggest climate threat to birds

While changes in average temperature and rainfall do affect birds, we found the increasing number of dangerously hot days had the greatest effect – especially in tropical regions.

This is a major concern because tropical birds often have small home ranges and are highly specialised in terms of the habitats and climates they persist in. In many cases tropical birds exist within a small range of heat tolerance.

At temperatures beyond a bird’s limit of endurance, they go into hyperthermia, where their body temperature rises uncontrollably. In this state, birds may adopt a drooped-wing posture to expose more skin for heat loss, hold their beaks open and pant rapidly, spread their feathers, and become lethargic or disoriented. In severe cases, they lose coordination, fall from perches, or even collapse unconscious.

A black-collared barbet (Lybius torquatus) from Botswana. Sergey Dereliev

If they survive the experience, they can suffer long-term damage such as heat-induced organ failure and reduced reproductive capacity. Heat exposure reduces breeding success by lowering adult body condition and reducing time spent foraging – because the birds must rest or seek shade during the hottest hours.

It also causes heat stress in eggs and nestlings. In extreme events, nestlings may die from hyperthermia, or parents may abandon nests to save themselves.

Heat also increases a bird’s demand for water — not because they sweat (birds lack sweat glands) but because they lose water rapidly through evaporative cooling. This happens mainly via panting (respiratory evaporation) and, in some species, gular fluttering (rapid vibration of throat skin to increase airflow), as well as evaporation through the skin. As temperatures climb, these processes accelerate, causing significant dehydration unless birds can drink more frequently or access moister food.

Our study found that across tropical areas, the impact of climate change on birds is perhaps even greater now than the impact of direct human activities such as logging, mining or farming. This is not to say habitat destruction due to these activities is not a serious issue – it clearly is a major concern to tropical biodiversity. But our study highlights the challenges climate change is already bringing to birds in tropical regions.

Extreme heat is bad for birds in more than one way. James Watson, Maximilian Kotz and Tatsuya Amano with icons from Flaticon, design by Canva.

A clear warning

Our research highlights the importance of focusing not just on average climate trends, but also on extreme events. Heatwaves are no longer rare, isolated incidents – they are becoming a regular part of life in many parts of the world.

If climate change continues unchecked, tropical birds – and likely many other animals and plants – will face increasing threats to their survival. Change may be too fast and too extreme for many species to adapt.

And as tropical regions host a huge share of the world’s biodiversity, including nearly half of all bird species, the ripple effects could be far-reaching.

Conservation strategies must take this into account. Protecting habitats from human industrial development remains important, but it’s no longer enough on its own. Proactive action to help species adapt to climate change needs to be part of wildlife protection plans – especially in the tropics.

Ultimately if we are to preserve global biodiversity, slowing down and eventually reversing climate change is essential. That means cutting greenhouse gas emissions, investing in ways to draw down existing carbon dioxide levels, and supporting policies that reduce our impact on the planet. The fate of tropical birds – and countless other species – depends on it.

Tropical bird population declined by one-third since 1980 due to climate change, featuring the study’s lead author Maximilian Kotz (Potsdam Institute for Climate Impact Research)

James Watson, Professor in Conservation Science, School of the Environment, The University of Queensland; Maximilian Kotz, Marie Curie Postdoctoral Research Fellow, Barcelona Supercomputing Center-Centro Nacional de Supercomputación (BSC-CNS), and Tatsuya Amano, Associate Professor, School of the Environment, The University of Queensland

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Climate Change and the Monsoon - impacts

Melting ice will strengthen the monsoon in northern Australia – but cause drier conditions north of the Equator

Sebnem Coskun/Anadolu via Getty Images

Corey J. A. Bradshaw, Flinders University; Cassandra Rowe, James Cook University, and Michael Bird, James Cook University

Almost two-thirds of the world’s population is affected by the monsoon – the annual arrival of intense rains in areas north and south of the Equator. These drenching rains tend to arrive during each hemisphere’s summer.

The East Asian monsoon north of the equator is the best known and best studied, because it affects the largest land area and the most people. But the southern Indo-Australian monsoon is vitally important to northern Australia, Indonesia and Papua New Guinea. To date, it has been studied much less.

To help fill this gap in knowledge, we analysed deep sediment from an unusual lagoon near Darwin in northern Australia. We looked at ancient pollen and chemical isotopes (different versions of the same chemical element) to look about 150,000 years back in time and glimpse changes to the monsoon. When types of pollen change, it tells us the monsoon has changed. Drier conditions favour the emergence of grasslands, while wetter climates favour forests.

Our new research suggests as the world gets hotter, the Indo-Australian monsoon will intensify and northern Australia will get wetter. This finding is consistent with research suggesting the East Asian monsoon could weaken, threatening agriculture and nature in heavily populated countries.

Location of Girraween Lagoon in monsoonal north Australia. Insert shows approximate dominant flows of the East Asian and Indo-Australian summer monsoons. Corey Bradshaw/Flinders University, CC BY-NC

The past held in a single lagoon

To examine how monsoons change over time, researchers drill sediment cores to track changes in pollen and chemical isotopes. For example, changes in hydrogen isotopes indicate changes in the intensity of the monsoon rain.

The problem is, these cores have to come from long-undisturbed lake sediments, because such places provide a continuous record of change.

To reconstruct past changes in monsoon patterns, undisturbed sediments have to be sampled carefully by extracting a thin “core” from the bottom sediments. Once researchers have this precious core, they can examine the changing proportions of pollen, chemical isotopes and other properties. The deeper you drill the core, the farther back in time you can look.

These exacting requirements are one reason the Indo-Australian monsoon is not as well understood as its northern cousin.

Fortunately, we have found one place which has kept a detailed environmental record over a long period: Girraween Lagoon on the outskirts of Darwin in the Northern Territory.

This lagoon was created after a sinkhole formed more than 200,000 years ago. It has contained permanent water ever since, and is slowly filling with sediment and pollen blown in from the surrounding landscape.

The 18-metre core from Girraween’s sediments gave us a 150,000-year record of environmental change in Australia’s northern savannahs.

It took hard work to extract the core from Girraween Lagoon.

Dipping into the past

If you walk around Girraween Lagoon today, you’ll see a tall and dense tree canopy with a thick grass understory in the wet season. But it hasn’t always been that way.

During the last ice age 20,000–30,000 years ago, the sea level was much lower and the polar ice caps much larger. As a result, the lagoon was more than 300 kilometres from the coast. At that time, the lagoon was surrounded by an open, grassy savannah with fewer, shorter trees.

A schematic showing the depth of the Girraween core and the associated time periods. Emma Rehn/Centre of Excellence for Australian Biodiversity and Heritage, CC BY-NC

About 115,000 years ago (and again 90,000 years ago), Australia was dotted with gigantic inland “megalakes”. At those times, the lagoon expanded into a large, shallow lake surrounded by lush monsoon forest, with almost no grass.

At times, tree cover changed radically. In fact, over one 3,000-year period, the percentage of tree pollen soared from 15% to 95%. That suggests a sweeping change from grassland to dense forest – meaning a switch from drier to wetter climate at a rate too fast to be explained by changes in Earth’s orbit.

Some of these changes are linked to the shifting distance between coastline and lagoon as well as predictable variation in how much solar energy reaches Earth.

A connection to the North Atlantic

Huge ice sheets covered large areas of the Northern Hemisphere during previous ice ages.

Remarkably, the evidence of their melting at the end of previous ice age was there in the sediment core from Girraween Lagoon.

When glacial ice melts rapidly, huge volumes of fresh water flood into the North Atlantic. These rapid pulses are known as Heinrich events. These pulses can shut down the warm Gulf Stream current up the east coast of North America. As a result, the Northern Hemisphere cools and the Southern Hemisphere warms.

Over the last 150,000 years, there have been 14 of these events. We could see evidence of them in the sediment cores. Every gush of fresh water in the Atlantic triggered higher rainfall over northern Australia because of the buildup of heat in the Southern Hemisphere as the Gulf Stream slowed.

What does this mean for the monsoon?

All this suggests the Indo-Australian monsoon will get more intense as the world gets hotter and more ice melts.

That would mean a wetter northern Australia. It could also bring more rainfall to other Australian regions, and neighbouring countries. At this stage, it’s too uncertain to predict what an intensifying monsoon would do to the southern parts of Australia.

We might already be seeing this shift. Weather records since the 1960s show northern Australia getting steadily wetter, and less rain in Australia’s southeast and southwest.

Trends in total annual rainfall in Australia from 1960 to 2020. Commonwealth of Australia Bureau of Meteorology, CC BY

What would this mean for people? Australia’s tropical north is not densely populated, which would reduce the human impact of an intensifying monsoon.

But while our research suggests the Indo-Australian monsoon strengthens during Heinrich events, earlier research has shown the East Asian and other Northern Hemisphere monsoons will weaken. Without reliable monsoonal rains, food and water supplies for billions of people could be at risk.

Corey J. A. Bradshaw, Matthew Flinders Professor of Global Ecology and Node Leader in the ARC Centre of Excellence for Indigenous and Environmental Histories and Futures, Flinders University; Cassandra Rowe, Senior Research Fellow, ARC Centre of Excellence for Indigenous and Environmental Histories and Futures, and College of Science and Engineering, James Cook University, and Michael Bird, JCU Distinguished Professor, ARC Centre of Excellence for Indigenous and Environmental Histories and Futures, James Cook University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Heat is being trapped on Earth in greater levels than modelled

Earth is trapping much more heat than climate models forecast – and the rate has doubled in 20 years

NASA, CC BY-NC-ND

Steven Sherwood, UNSW Sydney; Benoit Meyssignac, Université de Toulouse, and Thorsten Mauritsen, Stockholm University

How do you measure climate change? One way is by recording temperatures in different places over a long period of time. While this works well, natural variation can make it harder to see longer-term trends.

But another approach can give us a very clear sense of what’s going on: track how much heat enters Earth’s atmosphere and how much heat leaves. This is Earth’s energy budget, and it’s now well and truly out of balance.

Our recent research found this imbalance has more than doubled over the last 20 years. Other researchers have come to the same conclusions. This imbalance is now substantially more than climate models have suggested.

In the mid-2000s, the energy imbalance was about 0.6 watts per square metre (W/m2) on average. In recent years, the average was about 1.3 W/m2. This means the rate at which energy is accumulating near the planet’s surface has doubled.

These findings suggest climate change might well accelerate in the coming years. Worse still, this worrying imbalance is emerging even as funding uncertainty in the United States threatens our ability to track the flows of heat.

Energy in, energy out

Earth’s energy budget functions a bit like your bank account, where money comes in and money goes out. If you reduce your spending, you’ll build up cash in your account. Here, energy is the currency.

Life on Earth depends on a balance between heat coming in from the Sun and heat leaving. This balance is tipping to one side.

Solar energy hits Earth and warms it. The atmosphere’s heat-trapping greenhouse gases keep some of this energy.

But the burning of coal, oil and gas has now added more than two trillion tonnes of carbon dioxide and other greenhouse gases to the atmosphere. These trap more and more heat, preventing it from leaving.

Some of this extra heat is warming the land or melting sea ice, glaciers and ice sheets. But this is a tiny fraction. Fully 90% has gone into the oceans due to their huge heat capacity.

Earth naturally sheds heat in several ways. One way is by reflecting incoming heat off of clouds, snow and ice and back out to space. Infrared radiation is also emitted back to space.

From the beginning of human civilisation up until just a century ago, the average surface temperature was about 14°C. The accumulating energy imbalance has now pushed average temperatures 1.3-1.5°C higher.

Ice and reflective clouds reflect heat back to space. As the Earth heats up, most trapped heat goes into the oceans but some melts ice and heats the land and air. Pictured: Icebergs from the Jacobshavn glacier in Greenland, the largest outside Antarctica. Ashley Cooper/Getty

Tracking faster than the models

Scientists keep track of the energy budget in two ways.

First, we can directly measure the heat coming from the Sun and going back out to space, using the sensitive radiometers on monitoring satellites. This dataset and its predecessors date back to the late 1980s.

Second, we can accurately track the build-up of heat in the oceans and atmosphere by taking temperature readings. Thousands of robotic floats have monitored temperatures in the world’s oceans since the 1990s.

Both methods show the energy imbalance has grown rapidly.

The doubling of the energy imbalance has come as a shock, because the sophisticated climate models we use largely didn’t predict such a large and rapid change.

Typically, the models forecast less than half of the change we’re seeing in the real world.

Why has it changed so fast?

We don’t yet have a full explanation. But new research suggests changes in clouds is a big factor.

Clouds have a cooling effect overall. But the area covered by highly reflective white clouds has shrunk, while the area of jumbled, less reflective clouds has grown.

It isn’t clear why the clouds are changing. One possible factor could be the consequences of successful efforts to reduce sulfur in shipping fuel from 2020, as burning the dirtier fuel may have had a brightening effect on clouds. However, the accelerating energy budget imbalance began before this change.

Natural fluctuations in the climate system such as the Pacific Decadal Oscillation might also be playing a role. Finally – and most worryingly – the cloud changes might be part of a trend caused by global warming itself, that is, a positive feedback on climate change.

Dense blankets of white clouds reflect the most heat. But the area covered by these clouds is shrinking. Adhivaswut/Shutterstock

What does this mean?

These findings suggest recent extremely hot years are not one-offs but may reflect a strengthening of warming over the coming decade or longer.

This will mean a higher chance of more intense climate impacts from searing heatwaves, droughts and extreme rains on land, and more intense and long lasting marine heatwaves.

This imbalance may lead to worse longer-term consequences. New research shows the only climate models coming close to simulating real world measurements are those with a higher “climate sensitivity”. That means these models predict more severe warming beyond the next few decades in scenarios where emissions are not rapidly reduced.

We don’t know yet whether other factors are at play, however. It’s still too early to definitively say we are on a high-sensitivity trajectory.

Our eyes in the sky

We’ve known the solution for a long time: stop the routine burning of fossil fuels and phase out human activities causing emissions such as deforestation.

Keeping accurate records over long periods of time is essential if we are to spot unexpected changes.

Satellites, in particular, are our advance warning system, telling us about heat storage changes roughly a decade before other methods.

But funding cuts and drastic priority shifts in the United States may threaten essential satellite climate monitoring.

Steven Sherwood, Professor of Atmospheric Sciences, Climate Change Research Centre, UNSW Sydney; Benoit Meyssignac, Associate Research Scientist in Climate Science, Université de Toulouse, and Thorsten Mauritsen, Professor of Climate Science, Stockholm University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

As Los Angeles burns the World has crossed the 1.5C threshold

The highly destructive wildfires in Los Angeles US, in January 2025 are a warning to the World at large of the threat posed by climate change and its impact. Similar fires have been seen in the Mediterranean during their Summer period with similar devastating effects particularly in Greece.

The Copernicus Institute summarised the situation thus:  

“2024 saw unprecedented global temperatures, following on from the remarkable warmth of 2023. It also became the first year with an average temperature clearly exceeding 1.5°C above the pre-industrial level – a threshold set by the Paris Agreement to significantly reduce the risks and impacts of climate change. Multiple global records were broken, for greenhouse gas levels, and for both air temperature and sea surface temperature, contributing to extreme events, including floods, heatwaves and wildfires. These data highlight the accelerating impacts of human-caused climate change”.

Key points -

• 2024 was the warmest year in a multi-dataset record of global temperature going back to 1850.
• 2024 had a global average temperature of 15.10°C; 0.12°C higher than the previous highest annual value in 2023.
• 2024 was 0.72°C warmer than the 1991–2020 average, and 1.60°C warmer than the pre-industrial level, making it the first calendar year to exceed 1.5 above that level.
• The last ten years have been the warmest ten years on record.
• Each month from January to June 2024 was warmer than the corresponding month in any previous year. August 2024 equalled the record warmth of August 2023 and the remaining months from July to December were each the second warmest for the time of year, after the corresponding months in 2023.
• On 22 July 2024, the daily global average temperature reached a new record high of 17.16°C.

The link to the report (click): Global Climate Highlights 2024 

State of the Climate 2024 Report - continuing inconvenient truths abound

The State of the Climate Report 2024 from a consortium of scientists in mulitple institutions paints a grim picture for the direction of climate change with rising temperatures and greenhouse gas emissions. To quote an opening section of the report -

 “We are on the brink of an irreversible climate disaster. This is a global emergency beyond any doubt. Much of the very fabric of life on Earth is imperiled. We are stepping into a critical and unpredictable new phase of the climate crisis. For many years, scientists, including a group of more than 15,000, have sounded the alarm about the impending dangers of climate change driven by increasing greenhouse gas emissions and ecosystem change (Ripple et al. 2020 ). For half a century, global warming has been correctly predicted even before it was observed—and not only by independent academic scientists but also by fossil fuel companies (Supran et al. 2023 ). Despite these warnings, we are still moving in the wrong direction; fossil fuel emissions have increased to an all-time high, the 3 hottest days ever occurred in July of 2024.”

The graphs below from the report (figure 2) categorically demonstrate the upwards trends across a whole range of measures such as carbon dioxide emissions, methane emissions, nitrous oxide emissions, ocean heat, ocean levels and so on.

The report can be accessed at this link: State of the Climate Report 2024

No improvement in climate change measurements

Unprecedented peril: disaster lies ahead as we track towards 2.7°C of warming this century

Thomas Newsome, University of Sydney and William Ripple, Oregon State University

You don’t have to look far to see what climate change is doing to the planet. The word “unprecedented” is everywhere this year.

We are seeing unprecedented rapidly intensifying tropical storms such as Hurricane Helene in the eastern United States and Super Typhoon Yagi in Vietnam. Unprecedented fires in Canada have destroyed towns. Unprecedented drought in Brazil has dried out enormous rivers and left swathes of empty river beds. At least 1,300 pilgrims died during this year’s Hajj in Mecca as temperatures passed 50°C.

Unfortunately, we are headed for far worse. The new 2024 State of the Climate report, produced by our team of international scientists, is yet another stark warning about the intensifying climate crisis. Even if governments meet their emissions goals, the world may hit 2.7°C of warming – nearly double the Paris Agreement goal of holding climate change to 1.5°C. Each year, we track 35 of the Earth’s vital signs, from sea ice extent to forests. This year, 25 are now at record levels, all trending in the wrong directions.

Humans are not used to these conditions. Human civilisation emerged over the last 10,000 years under benign conditions – not too hot, not too cold. But this liveable climate is now at risk. In your grandchild’s lifetime, climatic conditions will be more threatening than anything our prehistoric relatives would have faced.

Our report shows a continued rise in fossil fuel emissions, which remain at an all-time high. Despite years of warnings from scientists, fossil fuel consumption has actually increased, pushing the planet toward dangerous levels of warming. While wind and solar have grown rapidly, fossil fuel use is 14 times greater.

This year is also tracking for the hottest year on record, with global daily mean temperatures at record levels for nearly half of 2023 and much of 2024.

Next month, world leaders and diplomats will gather in Azerbaijan for the annual United Nations climate talks, COP 29. Leaders will have to redouble their efforts. Without much stronger policies, climate change will keep worsening, bringing with it more frequent and more extreme weather.

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Bad news after bad news

We have still not solved the central problem: the routine burning of fossil fuels. Atmospheric concentrations of greenhouse gases – particularly methane and carbon dioxide – are still rising. Last September, carbon dioxide levels in the atmosphere hit 418 parts per million (ppm). This September, they crossed 422 ppm. Methane, a highly potent greenhouse gas, has been increasing at an alarming rate despite global pledges to tackle it.

Compounding the problem is the recent decline in atmospheric aerosols from efforts to cut pollution. These small particles suspended in the air come from both natural and human processes, and have helped cool the planet. Without this cooling effect, the pace of global warming may accelerate. We don’t know for sure because aerosol properties are not yet measured well enough.

Other environmental issues are now feeding into climate change. Deforestation in critical areas such as the Amazon is reducing the planet’s capacity to absorb carbon naturally, driving additional warming. This creates a feedback loop, where warming causes trees to die which in turn amplifies global temperatures.

Loss of sea ice is another. As sea ice melts or fails to form, dark seawater is exposed. Ice reflects sunlight but seawater absorbs it. Scaled up, this changes the Earth’s albedo (how reflective the surface is) and accelerates warming further.

In coming decades, sea level rise will pose a growing threat to coastal communities, putting millions of people at risk of displacement.

Accelerate the solutions

Our report stresses the need for an immediate and comprehensive end to the routine use of fossil fuels.

It calls for a global carbon price, set high enough to drive down emissions, particularly from high-emitting wealthy countries.

Introducing effective policies to slash methane emissions is crucial, given methane’s high potency but short atmospheric lifetime. Rapidly cutting methane could slow the rate of warming in the short term.

Natural climate solutions such as reforestation and soil restoration should be rolled out to increase how much carbon is stored in wood and soil. These efforts must be accompanied by protective measures in wildfire and drought prone areas. There’s no point planting forests if they will burn.

Governments should introduce stricter land-use policies to slow down rates of land clearing and increase investment in forest management to cut the risk of large, devastating fires and encourage sustainable land use.

We cannot overlook climate justice. Less wealthy nations contribute least to global emissions but are often the worst affected by climate disasters.

Wealthier nations must provide financial and technical support to help these countries adapt to climate change while cutting emissions. This could include investing in renewable energy, improving infrastructure and funding disaster preparedness programs.

Internationally, our report urges stronger commitments from world leaders. Current global policies are insufficient to limit warming to 1.5°C above pre-industrial levels.

Without drastic changes, the world is on track for approximately 2.7°C of warming this century. To avoid catastrophic tipping points, nations must strengthen their climate pledges, reduce dependence on fossil fuels, and accelerate the transition to renewable energy.

Immediate, transformative policy changes are now necessary if we are to avoid the worst effects of climate change.

Climate change is already here. But it could get much, much worse. By slashing emissions, boosting natural climate solutions and working towards climate justice, the global community can still fend off the worst version of our future.

Thomas Newsome, Associate Professor in Global Ecology, University of Sydney and William Ripple, Distinguished Professor and Director, Trophic Cascades Program, Oregon State University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Coral reefs in jeopardy

Devastating coral bleaching will be more common, start earlier and last longer unless we cut emissions

Sarah_lewis/Shutterstock

Camille Mellin, University of Adelaide and Damien Fordham, University of Adelaide

Coral bleaching is becoming much more common as a result of increasingly severe and frequent marine heatwaves. Four global mass bleaching events have happened since 1998. Two of these were in the past decade.

Unless greenhouse gas emissions are cut to slow global warming, our new research shows that, by 2080, coral bleaching will start in spring, rather than late summer. Some events will last into autumn. The Great Barrier Reef’s maximum annual heat stress will double by 2050 if emissions do not slow.

Marine heatwaves stress corals, which then expel the symbiotic algae living in their tissue. These corals are left white and weakened. While not all bleached corals die immediately, prolonged heat stress harms their health and reproduction.

Our research used daily data on sea surface temperatures (instead of monthly data that models typically use) and supercomputing to produce high-resolution projections of marine heatwaves. We showed the risk of coral bleaching will be greatest along the equator. That’s also where the most biodiverse coral reefs are found.

Coral reefs cover only 1% of our oceans, but host at least 25% of all marine species. More than half a billion people worldwide depend on coral reefs for food.

So coral reefs are vital for the health of the ocean and people. They are also among the ecosystems most at risk from climate change.

Longer bleaching season will hit spawning

The US National Oceanic and Atmospheric Administration monitors marine heatwaves globally. Seasonal coral bleaching alerts are based on this data. Predicting coral bleaching risk over entire decades has proved much more challenging.

Recent improvements in climate modelling now allow marine heatwaves and coral bleaching risks to be predicted with high accuracy. Using daily projections of heat stress from many global climate models, we show the severity and duration of coral bleaching will soon reach uncharted territory.

By mid-century coral bleaching is expected to start in spring for most of Earth’s reefs, rather than late summer as is typical today. In equatorial regions, corals will be at high risk of bleaching all year round by the end of the century.

In many regions, corals spawn only once a year. These spectacular mass spawning events happen in a single week following a full moon in spring.

By 2040, this spawning event could coincide with severe bleaching risk. This would greatly reduce their reproductive success, causing large-scale coral loss.

Acropora coral spawning on Magnetic Island in Queensland, Australia. Coral Brunner/Shutterstock

Equatorial regions most at risk

We show the future risk of severe coral bleaching is uneven globally.

The greatest risk is along the equator. Equatorial regions are home to the most biodiverse coral reefs, including conservation hotspots such as the Coral Triangle. To make matters worse, marine life in these regions is particularly vulnerable to accelerated climate change.

Many equatorial species are already living at temperatures near their upper tolerance. They also generally have low abilities to move to track shifting climates. This leaves them at high risk of extinction.

Future risk of coral bleaching under a high-emission scenario (top) and benefit from climate mitigation (bottom). Adapted from Mellin et al. Science Advances 2024

Our research shows equatorial regions are set to benefit least from efforts to curb emissions. We expect significant emission cuts will reduce the annual duration of severe bleaching conditions in all areas except these regions.

The projected highest climate impacts coincide with highest social reliance on coral reefs. This will challenge human populations that rely heavily on their local reefs for their livelihoods and nutrition.

Improving coral reef management

Our research identifies Earth’s reef regions that are at lowest risk of increased bleaching. This will help conservation managers and policymakers prioritise efforts to limit loss of coral reef biodiversity.

We predict much less risk of coral bleaching in regions such as the northern coasts of Venezuela and Colombia, Socotra Island (opposite the Gulf of Aden) and Alor Kecil in Indonesia. Seasonal upwellings occur here, bringing cooler water to the surface that’s likely to limit the severity of heatwaves.

Identifying these future havens for coral reefs will help maximise the success of coral conservation strategies such as assisted evolution, coral restoration or transplantation.

These strategies can help maintain healthy coral populations at local scales, particularly if used on reefs where future climate impacts will be lower. By pinpointing these havens, our research will strengthen coral conservation.

Our research includes a user-friendly web-based tool for mapping future coral bleaching. It will help pinpoint locations for effective management interventions.

Curbing greenhouse gas emissions is the main solution to reduce future climate impacts on corals. However, other strategies are also vital to maximise coral reefs’ adaptation to climate change.

Camille Mellin, Senior Lecturer and ARC Future Fellow, School of Biological Sciences, University of Adelaide and Damien Fordham, Associate Professor of Global Change Ecology, University of Adelaide

This article is republished from The Conversation under a Creative Commons license. Read the original article.