Climate Change - Australia's emissions target by 2035

 

The Albanese government has finally set a 2035 climate course – and it’s a mission Australia must accept

Dan Himbrechts/AAP, The Conversation, CC BY-SA

Tony Wood, Grattan Institute

The federal government has announced a long-awaited climate change target for 2035, committing to a reduction in emissions of between 62% and 70% below 2005 levels. Environmentalists claim the target is a failure, while some business groups and the opposition are likely to slam it as economic sabotage.

Setting a range target has two advantages. First, it provides flexibility to respond to whatever unfolds on the environment, technology or political front. Second, it avoids a frustrating political debate fixated on a single, precise future target.

Announcing the target on Thursday, Prime Minister Anthony Albanese said:

This is an ambitious but achievable target – sending the right investment signal, responding to the science and delivered with a practical plan. It builds on what we know are the lowest-cost actions we can deliver over the next decade while leaving room for new technologies to take things up a gear.

The target seeks to balance positive action with pragmatism. Achieving it requires a step-up in policies and implementation well beyond what has been achieved to date. This is a mission Australia must now accept.

A pathway to 2035

Climate change targets provide a clear vision of what the government is committed to delivering domestically. They are required under the Paris Agreement and affirm Australia’s membership of the global community.

The government announcement is aligned with advice delivered by the Climate Change Authority. That advice was delayed for months due to the election of US President Donald Trump – the policy repercussions of which the authority needed to consider – and the May federal election in Australia.

Last year, draft advice by the authority suggested an emissions reduction target of 65–75% by 2035.

More recently, a report from the Business Council of Australia claimed the cost of meeting a target above 70% was economically unacceptable.

If Australia is to meet its commitment to net-zero by 2050, and emissions fall in a straight line from 2030 to 2050, the 2035 target must be about 57%. Of course, this assumes that net-zero by 2050 is environmentally acceptable – which many, including the Grattan Institute, have argued is not.

And this week, the government’s National Climate Risk Assessment outlined alarming damage if emissions are not dramatically curbed. All this suggests Australia must set the strongest possible target.

So has the government’s target hit the sweet spot? Let’s tease that out.

Deeper cuts this decade

Australia’s emissions target for 2030 is a 43% emissions reduction, based on 2005 levels. We currently emit 440 million tonnes of carbon dioxide equivalent per year – 28% below 2005 levels.

To achieve the 2030 target, our annual emissions must fall by about 18 million tonnes a year. Meeting this target remains challenging. If the 2030 target is achieved, the annual rate of reduction would have to rise to 23 million tonnes or 33 million tonnes to meet the 62% or 70% target levels, respectively.

That’s why today’s targets are not lacking ambition. If the 2030 target is not achieved, then meeting the 2035 target – even the bottom of the range – only gets harder.

Disappointingly, however, the government has not clarified whether it’s essentially committing to 62% emissions reduction – with the option of greater ambition – or whether it will go for a 70% reduction but accept 62%. Or is it aiming for something in the middle?

The policy challenge ahead

Meeting the target will require progress across the economy – not just in the land sector and electricity generation, where most of the action has been to date. To achieve it, a major acceleration in government policy is needed.

So far, the Albanese government’s climate policy offering has been limited.

In 2022, the government established the Capacity Investment Scheme, which guarantees a certain revenue to renewable energy investors. It is designed to accelerate clean energy generation to meet Australia’s target of 82% renewables in the electricity mix by 2030. No further policy exists to reduce electricity emissions beyond that point.

The government also strengthened the Safeguard Mechanism, an innovation of the Abbott government to control emissions from heavy industry. And the New Vehicle Efficiency Standard (NVES) aims to drive down emissions from personal and small commercial vehicles. These policies must be ramped up to meet the 2035 target. The government has committed to reviewing the Safeguard Mechanism and the NVES, presumably to do just that.

Most of the light lifting in policy work has now been done. What’s needed now is policy to propel emissions reduction in harder-to-abate sectors of the economy – such as heavy vehicle transport and agriculture.

On Thursday, the government released a Net Zero Plan, along with blueprints for six major sectors of the economy outlining what needs to be done to get there.

Among other spending measures, it announced:

• A$5 billion in the National Reconstruction Fund to help industrial plants cut emissions
• $2 billion for the Clean Energy Finance Corporation
• $1.1 billion to encourage domestic production of clean fuels
• $40 million for kerbside and fast-charging of electric vehicles.

These are positive moves. But it’s still unclear how the government plans to integrate the policies with actually meeting the target.

Now the real work starts

Australia now has 2035 emissions targets and plans to meet them.

The target is a much-needed step on the path to net-zero, but it’s just the beginning. Delivering it will demand action across all sectors of the economy – and that work must start now.

The alternative – unchecked climate change – is not just irresponsible, but unthinkable.

Tony Wood, Program Director, Energy, Grattan Institute

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

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.

Health - the menace of mosquitoes

A warm, wet spring means more mozzies. How to protect yourself from the diseases they spread

Cameron Webb, University of Sydney

Mosquito bites are annoying. They can also have deadly consequences. So what diseases do mosquitoes in Australia carry?

And with warmer weather on its way and rain expected to continue, how can you prepare for the coming mosquito season?

Mosquitoes are deadliest animal

Mosquitoes kill more people than any other animal. Worldwide, more than half a million people die each year from mosquito bites that transmit malaria parasites.

Australia is fortunate to be free of major outbreaks of malaria, though occasional cases do occur.

The most common mosquito-borne disease in Australia is caused by Ross River virus. Around 5,000 cases are reported each year and, while never fatal, the illness can be severely debilitating. Symptoms include fever, rash, joint pain and fatigue.

Mosquito populations fluctuate year by year. A/Prof Cameron Webb (NSW Health Pathology), CC BY-NC-SA

Murray Valley encephalitis virus is responsible for very rare but potentially fatal disease. It’s detected most years in northern Australia.

There has been a resurgence of the virus in southeastern parts of Australia following flooding in recent years. Mosquitoes pick up the virus from waterbirds throughout the Murray Darling Basin before they pass on the pathogen to people. Mosquito and waterbird populations both boom after flooding.

Mosquitoes in some coastal areas of Victoria can also pass on the flesh-eating bacteria that can cause Buruli ulcer.

What about Japanese encephalitis?

Japanese encephalitis virus can cause fever, headaches, vomiting and, in rare cases, death.

Over the summer of 2021-22, there were 45 cases of Japanese encephalitis in southeastern Australia. This virus was never expected to spread so widely. In some parts of Australia, people died due to mosquito bites for the first time in around 50 years.

Scientists and health authorities thought Japanese encephalitis virus would transmit in a similar way to the closely related Murray Valley encephalitis virus, with outbreaks typically occurring after flooding that provided ideal conditions for both mosquitoes and the waterbirds carrying the virus.

But we now know pigs – especially feral pigs – are in the mix too, along with a range of other animals.

With gaps in our understanding of what drives local transmission, predictions of Japanese encephalitis activity are now proving to be less reliable. This makes it hard to work out the threat it may pose this summer.

Last summer, despite the lack of any substantial rainfall, the virus turned up even though mosquito (and waterbird) populations were generally low.

The virus also wasn’t limited to those areas where we’d expect to see it. There is growing evidence it’s made its way to the east coast, with the virus detected in the suburbs of Brisbane.

Ongoing wet weather can provide ideal conditions for mosquitoes. A/Prof Cameron Webb (NSW Health Pathology), CC BY-NC-SA

How will the weather impact mosquitoes this season?

Like all insects, mosquitoes thrive in warmer weather. But they also need water.

It doesn’t really matter if it’s a “wet” or “dry” summer, mosquitoes are always active. But sometimes there are more – lots more.

In most parts of Australia, there is currently no shortage of water. Some regions have had record rainfall this winter, with more on the way.

The Bureau of Meteorology is predicting above-average rainfall through to the end of the year. Once the weather warms up, it could be a “buzzy” start to mosquito season.

This doesn’t mean outbreaks of mosquito-borne disease are inevitable. But we need to be alert to the risks and how best to protect ourselves and family.

Scientists like me trap mosquitoes across Australia each summer to track changes in their abundance, as well as activity of pathogens. A/Prof Cameron Webb (NSW Health Pathology), CC BY-NC-SA

Monitoring mozzies

More rain means a greater risk of mosquito-borne disease. But outbreaks aren’t easy to predict, so surveillance is critical.

Australian state and territory health authorities undertake monitoring of mosquitoes and the pathogens they carry each year. The objective is to provide an early warning of elevated risk of mosquito-borne diseases. This may be due to increased mosquito activity or the detection of mosquito-borne pathogens.

Given the uncertainty around Japanese encephalitis, it’s also important to monitor locations where the virus has not yet been detected.

How to stay safe this spring and summer

There’s a lot you can do to protect yourself and family from mosquito bites and mosquito-borne disease.

A vaccine is available for those at risk of Japanese encephalitis. See your local health professional for advice on accessing the vaccine.

But there aren’t vaccines for the other local mosquito-borne diseases. Nor are there any specific treatments for these diseases. So preventing mosquito bites is the best way to protect yourself.

If you’re outdoors when mosquitoes are active, cover up with long pants, a long-sleeved shirt and covered shoes. Apply an insect repellent containing diethyltoluamide, picaridin, or oil of lemon eucalyptus to all exposed skin.

Skip the stickers, patches and wristbands, as the evidence shows they aren’t a reliable way to prevent bites.

Keep your property free of mosquito breeding grounds, too. Mosquitoes can lay eggs in any container that fills with water: a plant saucer, a bird bath, discarded plastic buckets, bottles or tins. Tip them out each week, cover them up or throw them away.

Cameron Webb, Clinical Associate Professor, School of Medical Science & Sydney Infectious Diseases Institute; Principal Hospital Scientist, University of Sydney

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

Health and exercise - weightlifting and bone density

Does weightlifting improve bone density?

Inti St Clair/Getty

Hunter Bennett, University of South Australia

You may have heard high-impact activity – exercise such as running, jumping, football and basketball – is good at building bone density and strength. But what about when you’re standing still, lifting weights at the gym?

The good news is weight training is great for bone health. But some exercises are more effective than others. Here’s what the science says.

What is bone density?

Bone density, also known as bone mineral density, is essentially a measure of how many minerals (such as calcium and phosphorus) are packed into your bones.

It gives you an indication of how solid your bones are, which is important because denser bones are generally less likely to break.

However, bone density is not quite the same as bone strength.

Bones also rely on a range of other compounds (such as collagen) to provide support and structure. So, even dense bones can become brittle if they are lacking these key structural components.

However, bone mineral density (measured with a bone scan) is still considered one of the best indicators of bone health because it is strongly linked to fracture risk.

While there is likely a genetic component to bone health, your daily choices can have a big impact.

What affects your bone health?

Research shows a few factors can influence how strong and dense your bones are:

Getting older: As we age, our bone mineral density tends to decrease. This decline is generally greater in women after menopause, but it occurs in everyone.

Nutrition: Eating calcium-rich foods – dairy in particular, but also many vegetables, nuts, legumes, eggs and meat – has been shown to have a small impact on bone density (although the extent to which this reduces fracture risk is unclear).

Exposure to sun: Sunlight helps your body make vitamin D, which helps you absorb calcium, and has been linked to better bone density.

Exercise: It is well established that people who do high-impact and high-load exercise (such as sprinting and weight training) tend to have denser and stronger bones than those who don’t.

Smoking: Older people who smoke tend to have lower bone density than those who don’t smoke.

Why does movement improve bone density?

In the same way that your muscles get stronger when you expose them to stress, your bones get stronger when they’re asked to handle more load. This is why exercise is so important for bone health – because it tells your bones to adapt and become stronger.

Many of us know that people at risk for bone loss – post-menopausal women and older adults – should be focused on exercising for bone health.

However, everyone can benefit from targeted exercise, and it’s arguably just as important to prevent declines in bone health.

In fact, whether you are male or female, the younger you start, the more likely you are to have denser bones into your older life. This is crucial for long-term bone health.

Do weights improve bone density?

Yes. One of the most effective exercises for bone health is lifting weights.

When you lift weights, your muscles pull on your bones, sending signals that encourage new bone formation. There is a large body of evidence showing weight training can improve bone density in adults, including in post-menopausal women.

But not all exercises are created equal. For example, some evidence suggests large compound exercises that place more load on the skeleton – such as squats and deadlifts – are particularly effective at increasing density in the spine and hips, two areas prone to fractures.

What type of weight training is best?

Lifting heavier weights is thought to produce better results than lifting lighter ones. This means doing sets of three to eight repetitions using heavy weights is likely to have a greater impact on your bones than doing many repetitions with lighter ones.

Similarly, it takes a long time for your bones to adapt and become denser – usually six months or more. This means for healthy bones, it’s better to integrate weight training into your weekly routine rather than do it in bursts for a few weeks at a time.

Exercises that use body weight, such as yoga and pilates, have many health benefits. However they are unlikely to have a significant impact on bone density, as they tend to put only light stress on your bones.

If you are new to weight training, you might need to start a bit lighter and get used to the movements before adding weight. And if you need help, finding an exercise professional in your local area might be a great first step.

Exercising for bone health is not complex. Just a couple of (heavy) weight training sessions per week can make a big difference.

If you’re concerned you have low bone density, speak to your doctor. They can assess whether you need to go for a scan.

Hunter Bennett, Lecturer in Exercise Science, University of South Australia

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

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 - city heatwaves increase when polluting aerosols are reduced

   aerosol cover in cities                    Shutterstock

In one of the more perverse impacts of environmental monitoring and pollution control, researchers have found that heatwaves increase as harmful aerosol pollution is reduced for the purpose of obtaining cleaner air. The warming has been found to be greater in populated locations where, commensurately, there tends to be more air pollution.

Aerosols cause lower temperatures as they reflect sunlight away from the planet either through altering the cloud composition or as a direct effect. Cleaning up the air and removing aerosols for better human health has resulted ironically in increasing heatwaves and generally warming the climate. Researchers have found that for most of last century, heatwave frequency was slowed despite rising greenhouse gas emissions. This changed from 2005 as declines in polluting aerosols became more apparent. A related issue is that aerosol pollution may have masked up to half the warming effect of greenhouse gas emissions up till now. The net impact has been that aerosol reduction has added heatwaves across the planet by approximately two days per decade.

The research Article can be accessed at this link: Anthropogenic aerosol changes disproportionately impact the evolution of global heatwave hazard and exposure