A crucial store of carbon in Australia’s tropical forests has switched from carbon sink to carbon source - The Conversation

The Conversation - Hannah Jayne Carle   Adrienne Nicotra   David Bauman 
                                 Michael N Evans   Patrick Meir

Alexander Shenkin, Author provided (no reuse)

Authors Hannah Jayne Carle Postdoctoral Researcher in Tropical Forest Ecology, Hawkesbury Institute for the Environment, WSU, Australian National University Adrienne Nicotra Professor of Ecology and Evolution, Research School of Biology, Australian National University David Bauman Research Scientist in Plant Ecology, Institut de recherche pour le développement (IRD) Michael N Evans Professor in Earth’s Systems Science, University of Maryland Patrick Meir Chair of Ecosystem Science, University of Edinburgh

One approach to help fight climate change is to protect natural forests, as they absorb some atmospheric carbon released by burning fossil fuels and store large volumes of carbon.

Our new research on Australia’s tropical rainforests challenges the assumption that they will keep absorbing more carbon than they release.

We found that as climate change has intensified over the past half-century, less and less carbon has been taken up and converted to wood in the stems and branches of the trees in these forests. 

Woody biomass is a large and relatively stable store of carbon in forests, and acts as an important indicator of overall forest health.

The effect has been so pronounced that the woody biomass of these forests has gone from being a carbon sink to a carbon source. 

This means carbon is being lost to the atmosphere due to trees dying faster than it is being replaced by tree growth.

This is the first time woody biomass in tropical forests has been shown to switch from sink to source. Our research indicates the shift likely happened about 25 years ago.

It remains to be seen whether Australian tropical forests are a harbinger for other tropical forests globally.

Above ground biomass of trees in 20 long-term Australian rainforest research sites has gone from carbon sink to source as more trees die and decay. Andrew Ford, Author provided (no reuse)

What did we find?

Since 1971, scientists have tracked around 11,000 trees in 20 tracts of tropical rainforest in Australia’s far northeast, now part of the Queensland Permanent Rainforest Plots Network. 

This 49-year research effort is one of the world’s longest and most comprehensive of its kind.

We analysed this long-term data and found a clear signal: woody biomass switched from being a carbon sink to a carbon source about 25 years ago.

Why? One reason: trees are dying twice as fast as they used to.

Tropical rainforest tree species are adapted to generally warm, wet conditions. As the climate changes, they are subjected to increasingly extreme temperatures and drier conditions.

These kinds of extreme climate events can damage wood and leaves, limiting future growth and leading to higher rates of tree death.

We also found tree deaths from cyclones reduced how much carbon these forests could absorb. 

Cyclones in far north Queensland are projected to become increasingly severe under climate change. They are also likely to push further south, potentially affecting new areas of forest.

Isn’t carbon dioxide plant food?

Burning fossil fuels and other human activities have increased carbon dioxide levels in the atmosphere. 

This should make it easier for plants to absorb CO₂ from the air, photosynthesise and grow. 

Given this, Earth system models predict higher atmospheric CO₂ levels will stimulate plant growth and increase how much carbon tropical forests can take up.

Also, remote sensing shows the canopies of tropical forests on Australia’s east coast are about 20% greener than they were in the 1980s. 

This suggests forest canopy growth has increased due to higher levels of CO₂ in the atmosphere. But this isn’t the whole picture.

Our data shows any potential increase in photosynthesis resulting in greener forest canopies has not translated to greater carbon storage in stems and branches.

The reason may be that tree growth can be limited by water, nutrients and heat. 

Our work suggest that warmer and drier conditions have limited tree growth even as CO₂ concentration has increased.

In a separate study, scientists artificially increased CO₂ and found the extra carbon taken up by leaves wasn’t being stored as extra woody growth. 

Rather, it was quickly released through roots and soil microbes. 

Australian rainforest canopies have become greener. But heat, drying and water availability are taking their toll on carbon sink capacity. Alexander Shenkin, Author provided (no reuse)

What about other forest carbon stocks?

It will be challenging to find out whether these forests as a whole (including wood, roots, leaves and soils) have declined in carbon sink capacity.

The use of a specialised research tool known as eddy covariance towers could help, as these measure overall CO₂ movement into and out of ecosystems.

As of yet, only 15 years of this kind of data from three tropical Australian sites is available, which currently limits our ability to describe the fuller impact of climate change.

In any case, we know carbon stored in forest canopies and soils is often broken down and released back to the atmosphere faster than carbon in woody biomass.

So while Australia’s tropical rainforest carbon stores remain large, they may be less secure and reliable than in decades past.

Long term datasets are vital

When people visit Australia’s tropical rainforests, they can see intact stretches of biodiverse forest and large, carbon-rich trees. 

It’s hard to directly see the changes we have detected – for now, they’re only visible in the data.

Without high-quality long-term datasets, this signal would have been almost impossible to detect. 

Unfortunately, persistent funding shortages for long-term ecological monitoring threaten the continuity of these hugely valuable datasets.

Australia has the potential to assume a globally leading role in tropical ecosystem science. 

In light of state and national biodiversity and emission reduction commitments, Australian governments should support continued monitoring of vital ecological research sites.

Tropical forests may not be saviours

The fact that woody biomass in Australia’s tropical rainforests is now a net source of carbon has major implications.

These findings challenge our future reliance on forests as natural absorbers of extra atmospheric carbon.

We don’t know yet whether all tropical forests will respond similarly. 

Evidence on carbon sink capacity is mixed. Rainforests in South America are showing a decline while African rainforests are generally not.

Overall, the world’s tropical forests remain very significant stores of carbon and biodiversity. Their protection remains essential despite the climate risks they face.

Links 

• Aboveground biomass in Australian tropical forests now a net carbon source
• Queensland Permanent Rainforest Plots
• Tropical tree mortality has increased with rising atmospheric water stress
• The risks to Australia of a 3°C warmer world
• Tropical forests are approaching critical temperature thresholds
• The response of land-falling tropical cyclone characteristics to projected climate change in northeast Australia
• Sensitivity of tropical carbon to climate change constrained by carbon dioxide variability
• Thirty-eight years of CO2 fertilization has outpaced growing aridity to drive greening of Australian woody ecosystems
• The fate of carbon in a mature forest under carbon dioxide enrichment
• What is an Eddy Covariance Flux Tower?

Battery Breakthroughs and the Path to Energy Independence - Lethal Heating Editor BDA

Key Points

Battery storage unlocks more wind solar and wave power by smoothing generation and demand.[1] New chemistries such as sodium-ion solid-state and long-duration flow systems are reaching commercial maturity.[2] Vehicle-to-grid systems let electric cars act as distributed batteries to support homes and grids.[3] Long-duration storage is essential for multi-day resilience and higher renewable shares.[4] With proper policy and investment towns and cities can become largely self-reliant on renewables and storage.[5] Deployment barriers remain cost regulatory and infrastructure related and must be addressed to scale benefits.[6]

Battery technology is central to replacing fossil fuels with renewable electricity.

Without reliable storage, wind, solar, and wave power cannot fully replace fossil fuel.^[1]

Large battery energy storage systems already balance supply and demand on grids in many countries.^[2]

Recent breakthroughs in chemistry and design promise longer duration, lower cost, and less reliance on scarce materials.^[2]

Electric vehicles are evolving to function as mobile batteries that can discharge power back to homes or the grid.^[3]

That change raises the prospect that vehicles could support household energy needs during outages and reduce peak demand.^[4]

Cities and towns are piloting integrated systems of renewables, storage, and digital control to become more self-reliant.^[5]

The speed of battery deployment will determine whether renewables can deliver deep decarbonisation within required timelines.^[6]

Realising these benefits demands policy investment and standards to manage costs, lifecycle, and grid integration.^[6]

Why storage is the linchpin

Wind, solar, and wave power are variable and often produce electricity at times when demand is low.^[1]

When generation exceeds demand without storage, the only options are curtailment or running fossil backups.^[1]

Battery energy storage systems store surplus energy and dispatch it later to meet demand and stabilise frequency.^[2]

Models show strategic placement of batteries reduces renewable curtailment and improves reliability.^[7]

Breakthrough chemistries and long-duration solutions

Lithium-ion still dominates, but alternatives such as sodium-ion and solid-state cells are moving toward commercial scale.^[2]

Sodium-ion batteries use more abundant sodium, reducing exposure to lithium supply constraints and cost pressure.^[8]

Solid-state batteries replace the liquid electrolyte with a solid material, promising improved safety and potentially higher energy density.^[2]

Flow batteries and other long-duration energy storage systems are designed to store energy for many hours or days, which is crucial for multi-day low wind or solar periods.^[4]

Material innovations are also reducing lifecycle environmental impacts, improving recycling, and lowering total system costs.^[2]

Vehicles as distributed power plants

Vehicle-to-grid systems allow bidirectional power flow between an EV and the grid.^[3]

That capability turns parked cars into flexible distributed storage that can reduce peak demand and provide ancillary services.^[4]

Pilot projects have demonstrated real world benefits, but widespread adoption requires standards, incentives, and battery warranty frameworks.^[3]

If widely implemented, Vehicle-to-Grid (V2G) could meaningfully reduce the need for new stationary storage but will not replace the need for long-duration assets.^[4]

Paths to self-reliant towns and cities

Urban areas can combine rooftop solar community batteries and smart management to reduce dependence on centralised fossil generation.^[5]

Energy planning that integrates distributed generation, storage, and demand response is essential for local self-reliance.^[5]

Many municipalities have set renewable targets and are running pilots that demonstrate how districts can move off fossil fuels.^[5]

Full city-scale transition timing depends on policy, finance, urban density, and existing infrastructure, but is achievable with concerted action.^[6]

Costs risks and system challenges

Although battery costs have fallen dramatically, further reductions are needed to scale long-duration storage affordably.^[6]

Regulatory reform is needed to value the services batteries provide, including capacity, reliability, and fast frequency response.^[6]

Recycling supply chain resilience and lifecycle emissions must be addressed to avoid shifting environmental burdens.^[2]

Timing and outlook

Industry and analysts expect sodium-ion and some long-duration systems to scale commercially within the latter half of this decade.^[2]

Widespread V2G adoption across vehicle fleets could become commonplace through the 2030s as EV stock and charger standards increase.^[4]

City and town transitions to high shares of local renewables plus storage are likely to progress, with many achieving major milestones in the 2030s and 2040s.^[5]

If deployment and policy fall short, the benefits will be delayed, and decarbonisation targets will be harder to meet.^[6]

Why this matters

Batteries make renewables reliable, which is central to cutting emissions from the electricity and transport sectors.^[1]

Vehicles serving as distributed batteries and cities moving to local renewables increase resilience, reduce fuel import exposure, and democratise energy.^[5]

Meeting climate targets depends on rapid scaling of storage alongside generation energy efficiency and electrification.^[6]

References

1. Intermittency and periodicity in net-zero renewable energy systems with storage — ScienceDirect
2. Battery storage supporting renewable energy is necessary and feasible, but faces challenges — UCL News
3. Beyond lithium-ion: emerging frontiers in next-generation battery — Frontiers in Batteries and Electrochemistry
4. Vehicle-to-Grid (V2G) technology: opportunities, challenges, and future — ScienceDirect
5. Empowering Urban Energy Transitions – Analysis — IEA
6. Policy Paper for fossil-free districts and cities — Energy Cities
7. Techno-Economic Planning of Spatially-Resolved Battery Storage Systems in Renewable-Dominant Grids Under Weather Variability — arXiv
8. Battery Buzz: 5 breakthroughs to watch in 2025 — RDWorldOnline
9. Global battery rollout doubled last year – but needs to be six times faster, says IEA — The Guardian
10. How Vehicle-to-Grid (V2G) Technology is Powering the Future of Energy — BCC Research Blog
11. Vehicle-to-Grid (V2G) integration in electric vehicles: review — MDPI/WEVJ
12. Urban Energy Transitions: A Systematic Review — MDPI Land
13. How cities can drive the transition from fossil fuels to clean energy — C40 Knowledge Hub

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The climate crisis is fuelling extreme fires across the planet - The Conversation

The Conversation - Hamish Clark

Roni Bintang/Getty

Author Hamish Clarke is Senior Research Fellow, The University of Melbourne.

We’ve all seen the alarming images. Smoke belching from the thick forests of the Amazon. Spanish firefighters battling flames across farmland. Blackened celebrity homes in Los Angeles and smoked out regional towns in Australia.

If you felt like wildfires and their impacts were more extreme in the past year – you’re right. Our new report, a collaboration between scientists across continents, shows climate change supercharged the world’s wildfires in unpredictable and devastating ways.

Human-caused climate change increased the area burned by wildfires, called bushfires in Australia, by a magnitude of 30 in some regions in the world. Our snapshot offers important new evidence of how climate change is increasing the frequency and severity of extreme fires. And it serves as a stark reminder of the urgent need to rapidly cut greenhouse gas emissions.

The evidence is clear – climate change is making fires worse. 

A view of the Palisades fire zone in Los Angeles, where climate change fuelled the fires in January.
Allen J. Schaben/Getty

Clear pattern

Our study used satellite observations and advanced modelling to find and investigate the causes of wildfires in the past year. The research team considered the role that climate and land use change played, and found a clear interrelationship between climate and extreme events.

Regional experts provided local input to capture events and impacts that satellites did not pick up. For Oceania, this role was played by Dr Sarah Harris from the Country Fire Authority and myself.

In the past year, a land area larger than India – about 3.7 million square kilometres – was burnt globally. More than 100 million people were affected by these fires, and US$215 billion worth of homes and infrastructure were at risk.

Not only does the heating climate mean more dangerous, fire-prone conditions, but it also affects how vegetation grows and dries out, creating fuel for fires to spread.

In Australia, bushfires did not reach the overall extent or impact of previous seasons, such as the Black Summer bushfires of 2019–20. Nonetheless, more than 1,000 large fires burned around 470,000 hectares in Western Australia, and more than 5 million hectares burned in central Australia. In Victoria, the Grampians National Park saw two-thirds of its area burned.

In the United States, our analysis showed the deadly Los Angeles wildfires in January were twice as likely and burned an area 25 times bigger than they would have in a world without global warming. Unusually wet weather in Los Angeles in the preceding 30 months contributed to strong vegetation growth and laid the foundations for wildfires during an unusually hot and dry January.

In South America, fires in the Pantanal-Chiquitano region, which straddles the border between Brazil, Bolivia and Paraguay, were 35 times larger due to climate change. Record-breaking fires ravaged parts of the Amazon and Congo, releasing billions of tonnes of carbon dioxide.

Protestors march for climate justice and against wild fires affecting the entire country in Sao Paulo, Brazil. 
Faga Almeida/Getty

Not too late

It’s clear that if global greenhouse gas emissions continue to rise, more severe heatwaves and droughts will make landscape fires more frequent and intense worldwide.

But it’s not too late to act. We need stronger and faster climate action to cut fossil fuel emissions, protect nature and reduce land clearing.

And we can get better at responding to the risk of fires, from nuanced forest management to preparing households and short and long-term disaster recovery.

There are regional differences in fires, and so the response also need to be local. We should prioritise local and regional knowledge, and First Nations knowledge, in responding to bushfire.

Action at COP30

Fires emitted more than 8 billion tonnes of carbon dioxide in 2024–25, about 10% above the average since 2003. Emissions were more than triple the global average in South American dry forests and wetlands, and double the average in Canadian boreal forests. That’s a deeply concerning amount of greenhouse pollution. The excess emissions alone exceeded the national fossil fuel CO₂ emissions of more than 200 individual countries in 2024.

Next month, world leaders, scientists, non-governmental organisations and civil society will head to Belem in Brazil for the United Nations annual climate summit (COP30) to talk about how to tackle climate change.

The single most powerful contribution developed nations can make to avoid the worst impacts of extreme wildfires is to commit to rapidly cutting greenhouse gas emissions this decade.

Links

• State of Wildfires Report 2024 - 2025
• Firefighters, landholders work to contain bushfires as extreme heat affects outback Queensland
• Poor phone service and confusing warnings risk lives during emergencies, Queensland review finds
• New research shows Black Summer’s megafires left lasting scars far beyond property damage
• Climate Summit 2025
• A crucial store of carbon in Australia’s tropical forests has switched from carbon sink to carbon source
• How wildfires and other climate disasters put health systems under extreme pressure

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Climate Change Squeezes Australian Farms and Pushes Food Prices Higher - Lethal Heating Editor BDA

Key Points

Australia’s changing climate is cutting crop yields and increasing farm costs [1] Extreme weather including droughts, floods, and heatwaves has intensified across major farming regions [2] Food prices are projected to rise 3–5% annually due to climate-related production pressures [4] Soil degradation, salinity, and erosion are compounding long-term agricultural risks [6] Adaptation efforts include drought-resistant crops, improved irrigation, and carbon farming [5] Policy and investment decisions will determine whether adaptation keeps pace with climate risks [8]

Australia’s farmers are confronting faster-than-expected damage from climate change, which is already squeezing crop yields and threatening to drive food prices higher.

Temperatures have climbed across the country and rainfall patterns have shifted, leaving some regions wetter, others drier and unpredictable.

A consolidated national assessment in 2024 documented record heatwaves, more intense rainfall events, and worsening droughts across key agricultural zones. ^[1]

Extended dry spells through 2024–25 cut wheat and barley yields in parts of New South Wales and Victoria well below trend levels. ^[2]

At the same time erratic floods and late heat have damaged summer crops in Queensland and northern NSW reducing some expected gains. ^[2]

Livestock producers in the Murray-Darling Basin report weaker pasture growth and tighter water allocations that increase feed and transport costs.

As production tightens, the cost of irrigation, fertiliser, feed, pest control, and logistics has risen, adding upward pressure on wholesale and retail food prices. ^[3]

Analysts now warn that staple food prices could rise by roughly three to five percent per year in the short to medium term if extreme climate events continue. ^[4]

Changing climate in Australia: trends and extremes

Australia’s climate is already in flux with measurable trends in temperature, rainfall and extreme events.

The national climate assessment reported rising average temperatures, more frequent and longer heatwaves, and an increase in compound events such as drought paired with heat. ^[1]

Rainfall trends are uneven, with increases in parts of northern Australia and declines across much of the south and southwest cropping zones.

The June 2025 Australian Crop Report noted that national winter crop production forecasts fell in 2025 relative to recent seasons, with specific reductions for barley and canola in several regions. ^[2]

Some summer crops such as sorghum saw localised benefits from above-average rain, but those gains were patchy and short-lived. ^[4]

Drought monitoring tools developed by national agencies are showing tighter correlations between climate stress and declines in farm profitability. ^[5]

In parts of Western Australia, farmers point to multi-decadal declines in growing season rainfall even as some yields have been sustained by improved agronomy. ^[1]

Vulnerable crops regions and livestock

Not all crops or regions face the same risk from climate disruption.

Wheat and barley in the southeast and southwest are highly exposed to reduced winter rainfall and late spring heat stress.

Canola is vulnerable to water stress at flowering and heat during seed fill, which reduces final yields.

Cotton and sugar producers in northern Australia risk altered monsoon timing, heat stress, and flood damage.

Horticulture—fruits, vegetables and nuts—is acutely exposed because many crops lack large-scale irrigation and are sensitive to short heat spikes and late frosts.

Livestock systems are affected when pasture growth declines, forcing higher spending on purchased feed and water or moving stock to feedlots.

Dairy and beef producers in the Murray Darling Basin face lower runoff and dryer soils that constrain feed availability and increase input costs.

Soil degradation, salinity, and erosion amplify climate impacts and reduce long-term productivity in several grain belt regions. ^[6]

How climate disruption drives up food costs

Climate effects raise food costs through various mechanisms.

Lower yields increase the cost per unit of agricultural output and reduce supply available for domestic markets and exports.

Water scarcity raises the cost of irrigation and energy, increasing on-farm operating expenses.

Heat and moisture stress increase pest disease and weed pressure, which raises spending on control measures.

Soil damage and erosion create remediation costs and undermine future productivity.

Extreme events disrupt transport, storage, and processing, creating spoilage losses and logistics rerouting at short notice.

Higher input costs for fuel fertiliser and labour in a stressed climate environment create knock on inflation in the farm to fork chain.

Projections for food prices and consumer impact

Market and banking analysts are already flagging tighter supplies and higher commodity prices linked to recent seasons of extreme weather. ^[2]

Agriculture outlooks for 2025 show mixed returns, with cost pressures offsetting some revenue gains in commodity markets. ^[7]

Short term food price rises of three to five percent annually are considered plausible for vulnerable categories such as fresh produce, meat, and some cereals if volatility continues. ^[4]

Lower income households and remote communities are likely to face the greatest affordability pressure.

Australia’s export orientation can exacerbate domestic tightness if international demand bids up prices or if exporters divert stocks abroad.

Over the medium term, structural shifts such as increased imports, altered diets, or broader reliance on alternative proteins could emerge if production constraints persist.

Adaptation strategies and policy responses

Farmers and policymakers are pursuing a mix of technological operational and financial adaptations.

Breeding drought tolerant and heat-resistant crop varieties and livestock breeds is a priority for research institutions.

Investing in efficient irrigation water capture and storage can reduce vulnerability to seasonal shortfalls.

Soil health practices, including no till cover crops and organic amendments, help retain moisture and reduce erosion.

Carbon farming and agroforestry can diversify income while enhancing resilience.

Insurance and co-investment schemes are being trialled to manage income volatility and catastrophic loss. ^[5]

Adoption barriers remain high because of upfront cost, fragmented landholdings, and limited extension services, especially for smaller producers.

Policymakers must balance decarbonisation efforts with measures that protect food security and farm viability. ^[8]

What to watch going forward

Several indicators will signal whether adaptation is keeping pace with accelerating climate risk.

Seasonal rainfall departures from long-term baselines will be an early indicator of stress in cropping zones. ^[6]

Regional yield variance and crop failure rates will reveal where vulnerabilities are emerging.

Rates of adoption for resilient technologies such as precision irrigation, drought tolerant varieties, and soil practices will show structural change.

Movements in input costs, wholesale commodity prices, and retail food inflation will provide early warning for consumers.

Government policy shifts, including subsidy design and research funding, will strongly influence the pace and equity of adaptation.

If climate stress outpaces adaptation, expect continuing pressure on farm margins, greater price volatility, and increasing challenges for food affordability.

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References

1. State of the Climate 2024 – Bureau of Meteorology and CSIRO
2. Australian Crop Report June 2025 – DAFF / ABARES
3. Agricultural cost pressures and resilience – CSIRO agrifood systems research
4. Agriculture and commodity outlooks 2025 – Banking and market analysts
5. Australian Agricultural Drought Indicators and adaptation progress – ABARES / CSIRO
6. Salinity and soil degradation in Australian agriculture – National assessments and monitoring
7. Agricultural Commodities Report December 2024 – Department of Agriculture, Fisheries and Forestry
8. Policy analysis on climate adaptation and food security – Climate Council / industry papers
9. Bureau of Meteorology climate data and seasonal outlooks

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Record CO₂ Levels Push the Planet Toward Dangerous Warming Thresholds - Lethal Heating Editor BDA

Key Points

Atmospheric CO₂ is at record levels above 420 ppm. [1] Global fossil CO₂ emissions reached new highs near 37–38 GtCO₂. [2] Energy and industry dominate emissions; land-use and wildfires add variability. [3] Natural sinks remove ~50% of emissions but are weakening in some regions. [2] Without rapid cuts the planet is likely to overshoot 1.5 °C this decade. [4] High-impact levers: electricity decarbonisation, end of unabated fossil fuels, and protection of land sinks. [5]

Atmospheric carbon dioxide (CO₂) has reached record levels.

The most recent global average CO₂ reading is in the low-to-mid 420s parts per million, well above pre-industrial levels, and the year-to-year rise in 2024 was the largest on record. ^[1]

Global fossil CO₂ emissions remain near all-time highs at about 37 to 38 gigatonnes per year. ^[2]

Energy production, industry and transport are the largest human sources, with land-use change and wildfires causing large but variable releases of CO₂. ^[3]

Natural sinks in the oceans and on land still absorb roughly half of the emissions, but evidence shows a regional weakening under heat and drought stress. ^[2]

Climate models and current policy pledges indicate a high probability of breaching the 1.5 °C threshold and moving toward 2 °C or more this century, unless emissions decline sharply. ^[4]

Feedbacks such as permafrost thaw and forest dieback could amplify atmospheric CO₂ and make targets harder to reach. ^[4]

The technical pathways to limit warming exist, but they require rapid, deep cuts in fossil fuel use, protection and restoration of natural sinks, and substantial carbon removal. ^[5]

Delays increase the risk of lock-in, stranded assets and irreversible impacts, so near-term action is essential. ^[4]

Current status & trends

Global mean atmospheric CO₂ reached a new record in 2024 with global averages reported in the low 422–425 ppm range depending on the dataset. ^[1]

The year-to-year increase recorded between 2023 and 2024 was the largest in the instrumental record at roughly 3.5 to 3.8 ppm. ^[1]

Pre-industrial CO₂ was about 280 ppm so current levels are roughly 50 percent higher than the baseline used by climate science. ^[4]

The Global Carbon Project and energy agencies report fossil fuel and cement CO₂ near 37–38 GtCO₂ in 2023–24 with modest growth in 2024. ^[2]

Annual emissions have not shown a sustained peak and small year-to-year fluctuations mask an upward trend in total atmospheric loading. ^[2]

Major sources and contributors

The energy sector — power generation and heat — is the largest source of CO₂ from fossil fuels. ^[3]

Industry, including steel, aluminium and chemical production, and cement, causes a substantial share of emissions. ^[3]

Transport, particularly road transport and aviation, is another major source and growth area in many regions. ^[3]

Land-use change, deforestation and large wildfires add pulses of CO₂ and reduce the capacity of ecosystems to store carbon. ^[2]

China, the United States, the European Union, India and other high-emission economies together account for the bulk of national emissions in absolute terms. ^[2]

Per-capita emissions remain highest in several wealthy nations and among high-emitting consumers, highlighting equity issues in mitigation. ^[4]

Oceans and terrestrial ecosystems currently absorb around half of human emissions, but their efficacy varies year to year and can decline under heat and drought stress. ^[2]

Impacts across domains

Higher CO₂ and the resulting warming increase heat-related illness, respiratory disease from wildfires, and infectious disease risk in some regions. ^[4]

Climate change amplifies displacement and migration pressure where livelihoods and water supplies are undermined. ^[4]

Economies face rising costs from extreme events, lost labour productivity, infrastructure damage and higher insurance premiums. ^[4]

Ecological impacts include range shifts, coral bleaching from warmer and acidifying oceans, and increasing extinction risks for sensitive species. ^[4]

Politically, failure to cut emissions intensifies diplomatic tension, complicates development and raises governance challenges for adaptation finance. ^[4]

Culturally, Indigenous peoples and local communities experience loss of land and traditions, while climate change becomes a growing theme in art, law and public debate. ^[4]

Projections and long-term implications

IPCC-class climate models indicate that, under current policies, global warming is likely to exceed 1.5 °C this decade and move toward or beyond 2 °C by 2100. ^[4]

Remaining carbon budgets for a two-thirds chance of 1.5 °C are small and require rapid deep cuts in CO₂ emissions this decade. ^[4]

Feedbacks such as permafrost carbon release, forest dieback and reduced ocean uptake could add several hundred million tonnes to future CO₂ and amplify warming. ^[4]

Scenarios range from business-as-usual with rising emissions to rapid decarbonisation with net-zero around mid-century and substantial negative emissions thereafter. ^[5]

Urgency, feasibility and timing for reduction

To limit warming to near 1.5 °C global CO₂ emissions must fall sharply and reach net zero roughly by mid-century with rapid declines by 2030. ^[4]

Reducing atmospheric CO₂ concentrations as well as emissions matters because current CO₂ will persist and continue to drive warming for centuries. ^[4]

High-impact interventions include phasing out unabated coal, halting new oil and gas infrastructure, electrifying transport, decarbonising industry and scaling nature-based protection. ^[5]

Carbon dioxide removal (CDR) technologies and restored ecosystems can help manage residual emissions but they face cost, scale and governance constraints. ^[5]

Delays increase entropy in the energy system, cost more to reverse, and raise the chance of passing irreversible ecological thresholds. ^[4]

Conclusion and recommended priorities

The empirical evidence is clear: CO₂ is at record levels, emissions remain near all-time highs and natural sinks are under stress. ^[1]

Priority actions are immediate and deep cuts to fossil fuel use, protection and restoration of forests and soils, rapid electrification and investment in proven removal where needed. ^[5]

Policymakers must couple emissions targets with concrete sectoral plans, finance for the global south and just transitions for workers and communities. ^[4]

Delaying action raises costs and risk and reduces options; the mission to reduce CO₂ is urgent and feasible if nations act at scale now. ^[4]

References

1. Climate change: atmospheric carbon dioxide – NOAA Climate.gov
2. Global Carbon Budget 2024 – Global Carbon Project
3. CO₂ and other greenhouse gas emissions – Our World in Data
4. Summary for Policymakers – IPCC AR6 Synthesis Report (2023)
5. CO₂ Emissions – Global Energy Review 2025 – IEA

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Q&A: How can Australia achieve climate change net-zero emissions by 2050 or earlier? - Lethal Heating Editor BDA

Key Points

The federal plan sets priorities for electricity, electrification, clean fuels, new technologies and carbon removals. [1] Every sector must rapidly decarbonise with both proven and emerging solutions. [2] Clear government policy, streamlined approvals and coordinated regulation are essential. [3] Households and businesses must electrify, improve efficiency and adopt low-carbon choices. [4] Delaying action raises costs, risks stranded assets and increases climate damage. [5] Targeted public finance and industry policy are already mobilising investment at scale. [6]

Australia aims to reach net-zero greenhouse gas emissions by 2050 or sooner, and the Federal Government has outlined priorities to achieve this goal.

The plan emphasises clean electricity, electrification and efficiency, an expansion of clean fuels, investment in new technologies, and scaled carbon removals. ^[1]

Every sector of the economy will need to reduce emissions quickly, including electricity, transport, buildings, industry, and agriculture. ^[2]

The task requires coordinated action by federal and state governments, local councils, business, investors, communities, and households. ^[3]

Success depends on clear policy signals, streamlined planning and approvals, stronger industrial strategy and public finance that leverages private capital. ^[6]

Households and firms must adopt electric vehicles, heat pumps, rooftop solar, efficient appliances and lower-carbon diets and supply chains. ^[4]

Scientific and economic modelling shows delaying action increases long-term costs and the risk of more extreme climate impacts. ^[2]

Practical examples from councils, regional projects and public finance bodies show that rapid progress is feasible when regulation and investment align. ^[6]

Failing to meet net-zero by 2050 would increase damage from heat, fire, flood, and drought and create economic and social costs that are far higher than the price of early action. ^[5]

Why net zero by 2050 matters

Net zero means balancing greenhouse gases emitted with removals, so the net increase in atmospheric greenhouse gases is zero.

Scientists and policy bodies say net-zero is essential to limit warming and avoid the worst physical and economic impacts of climate change. ^[2]

Every year of delay adds cumulative carbon to the atmosphere and makes stabilisation harder and more expensive.

Failing to achieve net-zero by mid-century increases the frequency and severity of heatwaves, fire weather, floods, and droughts in Australia.

The cost of inaction shows up in damaged infrastructure, disrupted supply chains, rising insurance costs, and pressure on health and emergency services. ^[5]

It also risks stranded fossil-fuel assets and lost opportunities in growing global markets for low-carbon exports such as green metals and hydrogen. ^[6]

National and government action

The Climate Change Act 2022 provides the legislative foundation for Australia’s emissions targets and annual reporting obligations. ^[3]

In 2025 the Federal Government set a stronger near-term target and outlined a Net Zero Plan that organises effort around five decarbonisation priorities. ^[1]

Key domestic levers include tightening the Safeguard Mechanism, accelerating grid connection approvals and reforming planning to speed deployment of renewable generation and transmission. ^[2]

Tax incentives and production credits for critical minerals and renewable hydrogen are designed to anchor supply chains and attract investment. ^[6]

Public finance vehicles such as the Clean Energy Finance Corporation are already mobilising large capital commitments to deliver projects and unlock private funding. ^[4]

Sectoral change and who must act

• Electricity: the grid must move to near-100 per cent low-emissions generation supported by storage, demand response and better interconnection. ^[2]
  That requires transmission upgrades, reform of market design and faster approvals for large-scale renewables and long-duration storage. ^[2]
• Transport: light-vehicle fleets must electrify rapidly and governments must build charging infrastructure and tighten fuel efficiency rules. ^[2]
  Freight, shipping, and aviation need low-carbon fuels and efficiency improvements and pathfinding policies for hydrogen and sustainable aviation fuels. ^[6]
• Buildings: new homes and commercial buildings should be zero-emissions-ready and existing buildings must be retrofitted with insulation, electric heating and induction cooking. ^[2]
  Regulation, targeted subsidies and consumer incentives will be necessary to lift retrofit rates at scale.
• Industry: heavy industry requires low-carbon process heat, hydrogen and carbon-capture where necessary, alongside circular materials strategies. ^[2]
  Industrial clusters located near cheap renewable energy or hydrogen supply will lower costs and speed deployment. ^[6]
• Agriculture and land: farmers can reduce methane and nitrous oxide emissions through feed, fertiliser, and manure practices and expand on-farm carbon storage through reforestation and soils. ^[2]

Australian case studies and evidence

The Climate Change Authority’s Sector Pathways Review compiles sector-by-sector options and shows feasible routes to net-zero with current and near-term technologies. ^[2]

CSIRO’s pathway modelling provides technical scenarios and demonstrates that rapid decarbonisation is technically feasible if policy and investment align. ^[3]

The Clean Energy Finance Corporation reported record commitments and shows public finance can mobilise private capital at scale when policy signals are clear. ^[4]

Media reporting and independent analysis from 2025 record the government’s higher near-term targets and the policy measures intended to meet them. ^[1]

Challenges and the path ahead

Major obstacles include grid congestion, planning and approval delays, workforce shortages and the higher upfront cost of some clean technologies. ^[2]

Coordinated governance across federal, state and local levels is difficult but essential for efficient rollout and avoiding regulatory whiplash.

A carefully managed just transition is required for workers and regions dependent on fossil fuels, and that requires retraining, targeted investment and clear regional development plans. ^[4]

Early and well sequenced policy reduces the risk of locking in high-emissions infrastructure and lowers the long-run cost of transition. ^[2]

Consequences of failure and urgency

Failing to reach net-zero by 2050 increases the likelihood of more severe climate extremes and raises long-term adaptation costs for governments and households. ^[5]

Economic consequences include stranded assets, higher insurance premiums, disrupted industries and weaker performance in emerging low-carbon export markets. ^[6]

By contrast, a credible, well governed transition can create jobs, attract investment and sustain Australia’s economic competitiveness in a decarbonising global economy. ^[4]

References

1. Australia vows to cut emissions 62 to 70 per cent by 2035 — ABC News
2. Sector Pathways Review — Climate Change Authority
3. Pathways to Net Zero Emissions — CSIRO
4. Annual Report 2024–25 — Clean Energy Finance Corporation
5. Modelling sectoral pathways to net zero emissions — CSIRO
6. Australia passes tax incentives law for critical minerals — Reuters

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Q&A: How can Australia prepare for more frequent and severe natural disasters linked to climate change? - Lethal Heating Editor BDA

Key Points

Australia faces more frequent heatwaves, bushfires, floods, droughts, cyclones, and coastal inundation.[1] Vulnerable groups include the elderly, remote and low-income communities, First Nations people, and coastal populations.[2] Recent case studies: the Black Summer bushfires and the 2022 Northern Rivers floods.[3] Preparation must combine mitigation (emissions cuts) and adaptation (early warning, resilient infrastructure).[4] Safeguarding requires land management, insurance reform, community training, habitat corridors and species migration planning.[5]

Australia Faces a Rising Wave of Climate-Driven Natural Disasters

Australia is already experiencing a rising burden of severe natural disasters driven by climate change.

Heatwaves, bushfires, floods, droughts and coastal inundation are intensifying in both frequency and severity.

Those in remote regions, older age brackets, First Nations communities and low-income coastal towns are most exposed.

Recent events such as the 2019–20 Black Summer bushfires and the 2022 Northern Rivers floods show the urgent need for concerted adaptation.

National and local strategies must combine emissions reductions, early warning systems, resilient design, ecological resilience and social equity.

Types and Frequency of Major Disasters

Australia faces several disaster types that climate change is amplifying.

Heatwaves are becoming more frequent, lasting longer, and reaching higher peak temperatures.^[6]

The State of the Climate report says Australia has seen an increase in extreme heat events over land and ocean.^[6]

A recent study estimated that between 2016 and 2019 heatwaves caused 1,009 deaths in Australia.^[7]

Bushfires are worsening.^[1]

Climate change leads to more “dangerous fire weather days” and longer fire seasons, especially in southern and eastern Australia.^[1]

In the Black Summer 2019–20, over 24 million hectares burned and more than 3,000 homes were lost.^[1]

Floods and heavy rainfall events are intensifying.^[1]

Warmer air holds more moisture, so storms release more rain in concentrated bursts.^[1]

Recent east coast lows, for example in June–July 2025, caused flooding across parts of New South Wales.^[8]

Droughts and dry conditions are projected to become more common in many regions, especially the south and east.^[1]

Tropical cyclones are not expected to become more frequent overall, but a larger share may reach high intensities.^[1]

Coastal inundation and sea level rise will exacerbate storm surges and land loss.^[1]

Vulnerable Areas and Populations

Some places and people face much greater risks than others.

Coastal zones and low-lying areas are vulnerable to sea-level rise, storm surge, erosion and saltwater intrusion.^[9]

Rural and remote communities with limited access to services face heightened exposure to fire, flood isolation, and heat stress.^[2]

Older adults, people with chronic illnesses, children, those on low incomes, and socially isolated residents are more vulnerable during extreme events.^[2]

Biodiversity and ecosystems also face uneven threat.^[10]

Bushfire “mega-studies” link the 2019–20 fires to dramatic wildlife loss and habitat collapse.^[10]

Coral reef systems, such as the Great Barrier Reef, suffer from repeated bleaching triggered by marine heatwaves.^[11]

Recent Case Studies

The Black Summer bushfires (2019–20) remain a stark example of climate-intensified disaster.^[3]

They burned more than 24 million hectares, destroyed thousands of properties and killed or injured many, including wildlife.^[3]

The 2022 Northern Rivers floods in New South Wales marked one of Australia’s costliest disasters.^[1]

Multiple river systems overflowed, lives were lost, infrastructure was wrecked, and recovery stretched for years.^[1]

How to Prepare — Safeguarding People, Property and Nature

• Australia needs both mitigation (cutting emissions) and adaptation (adjusting to change).^[4]
• Without strong emissions reductions, dangers will accelerate.^[4]
• Early warning systems and forecasting must improve.^[12]
• Land and fuel management is vital.^[5]
• Resilient infrastructure and building codes must evolve.^[7]
• Ecosystem protection and restoration matter.^[10]
• Insurance and economic policies must be reformed.^[13]
• Community engagement and equity must guide adaptation.^[13]
• Animal and plant protection approaches include wildlife rescue networks, seed banking, captive breeding and habitat corridors.^[10]
• Monitoring, research, and iterative learning are essential.^[14]

Conclusion

Australia faces a rising toll from climate-driven disasters: heatwaves, bushfires, floods, droughts, cyclones and coastal inundation.^[1]

Those in remote, coastal and marginal areas—especially older, lower-income and First Nations communities—are most exposed.^[2]

The Black Summer bushfires and the Northern Rivers floods show the damage is already underway.^[3]

Australia must act decisively: cut emissions, build resilient systems, protect ecosystems and empower communities.^[4]

Only through integrated, equitable adaptation and mitigation can the nation safeguard its people, economy, and biodiversity in a hotter world.

References

1. Impact of Climate Change and More Frequent and Severe Natural Disasters
2. Health and Housing Consequences of Climate-Related Disasters
3. Lessons from the 2019/2020 Black Summer Bushfires in Australia
4. CSIRO Report on Climate and Disaster Resilience
5. Case Study: Bushfire and Distribution – Climate Change in Australia
6. State of the Climate 2024
7. Heatwaves Caused More Than 1,000 Deaths in Australia, Study Finds
8. Australian East Coast Low
9. Rising Oceans to Threaten 1.5 Million Australians by 2050
10. Mega-fires, Mega-Study – Australian Geographic
11. Coral Bleaching and Marine Heatwaves – AP News
12. Ensemble Quantile-Based Deep Learning Framework for Streamflow and Flood Prediction in Australian Catchments
13. Natural Disasters and Climate Risk – Parliamentary Library Briefing
14. Science and Science Communication of Anthropogenic Climate Change and Weather Extremes

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