Like humans, many animals form lasting monogamous relationships. Most birds pair up to produce and raise offspring together over many years. However, as with humans, they also commonly “divorce” – terminating the pair bond well before the death of either partner.

Our new research examines the link between extreme weather events and divorce in a small monogamous tropical songbird.

We found extreme events – at both ends of the spectrum, both wet and dry – increase divorce rates in these birds.

With climate patterns becoming increasingly erratic, it’s vital to understand how such extreme events affect the species we share our planet with. If it’s disturbing their love lives, this may have dire consequences for the ability of species to reproduce and survive.

Back from the brink of extinction

The Seychelles warbler is endemic to the Seychelles islands in the Indian Ocean.

Once on the brink of extinction, with just 26 birds left in the world, this species now has a stable population on Cousin Island. It’s a great conservation success story – to save the species, the entire island and surrounding sea was turned into a nature reserve in the late 1960s and early 1970s.

Seychelles warbler pairs can stay together for up to 15 years. But somewhere between 1% and 16% of partnerships break up every year.

Why? It’s thought divorcing may allow these birds to correct for a poor choice of partner. A poor match typically results in a failure to produce chicks and fledglings, which makes the birds reconsider their choice of partner and look elsewhere. But sometimes they divorce for no apparent reason.

Many factors could misinform these birds, causing them to separate when it is not in their best interests. Maybe even bad weather.

Using a unique dataset spanning decades, we determined the relationship status of all birds on the island over 16 years. We then related that to rainfall data from the local meteorological station.

Fair-weather friends

We found the probability of divorce was closely associated with the amount of rainfall experienced in the seven months leading up to and during the breeding season. Divorce rates spiked both when rainfall was extreme: either very wet or very dry.

A super El Niño event in 1997 caused exceptionally heavy rainfall that year: 1,430mm compared with the average 884mm. Many Seychelles warblers divorced that year (15.3%).

More couples also broke up in drought years.

It seems these birds tend to stick together when the weather is good, but separate when it turns bad.

How weather affects partnership stability

Divorce in many species is often directly linked to poor breeding success, when a couple fails to rear young in the prior breeding season. But in our study we found no evidence to suggest that’s an issue in Seychelles warblers.

While the period of rainfall that predicted divorce also influenced the ability of these birds to produce offspring, failing to become parents did not make Seychelles warbler pairs more likely to divorce. Some birds that divorced did produce offspring successfully, and some that didn’t produce offspring stayed together. This suggests other, more complex factors may be at play.

Extreme weather affects the physical environment, changing food availability, habitat and nesting conditions. Prolonged lack of rain before breeding begins can also affect the health of birds.

Maintaining the right body temperature during periods of extreme rainfall is challenging for many bird species. This may increase the level of stress birds experience and increase instability in their partnerships. But it may not necessarily result in a failure to breed altogether.

What we can learn from this

Our new research sheds light on another heartbreaking consequence of climate change: extreme events are destabilising partnerships in wild animals.

Birds such as the Seychelles warbler are particularly vulnerable to these changes because, like many other species, their reproductive strategies are closely linked to environmental conditions.

As we continue to face the challenges posed by climate change, studies such as this are essential. They offer vital information for conservationists working to protect species that are highly sensitive to their environment. This is especially important particularly for isolated populations that can’t move to adjust.

As extreme weather is becoming more common, we will likely see more dramatic shifts in the social structures of many species, affecting not only their survival but the entire ecosystems they inhabit.

Frigg Janne Daan Speelman, PhD Candidate in behavioural ecology, Macquarie University

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

After this spring’s heat, humidity, rain and storms across Australia, you may be wondering what summer has in store.

The Bureau of Meteorology’s long-range summer forecast, released today, gives some indication of how the coming months are likely to unfold. Notwithstanding the challenges of making these forecasts, seasonal prediction can be very valuable for climate-sensitive industries such as agriculture, as well as being of great public interest.

The latest outlook from the bureau suggests we’re in for more of the unsettled weather we’ve been experiencing during spring. On average, hotter night-time temperatures and higher rainfall are expected over summer.

Meanwhile, this summer’s seasonal bushfire outlook shows an increased risk of fire across large parts of Australia, such as southeastern South Australia and western Victoria, central Australia around Alice Springs, and southern stretches of Western Australia.

Unseasonal November weather in the southeast

This spring has been a mixed bag, with wetter than normal conditions through much of northwestern Australia, as well as swings between hot and dry weather and cooler, wetter conditions elsewhere.

There were several severe weather events, starting with record-breaking heat across the north and floods in Tasmania.

In recent days, eastern Australia experienced severe storms with unusually high humidity in states such as Victoria.

So what can we expect over the next three months? That’s a simple question with a not-so-easy answer.

How reliable are long-range forecasts?

Long-range seasonal forecasting is challenging, as the science is still developing rapidly. In contrast, short-term weather forecasting has been around much longer.

For daily weather forecasts, the skill lies in knowing the recent weather conditions very well. Having more observations of properties such as temperature, wind and rainfall helps to improve these forecasts. This information is then fed into weather models, which in most places are accurate for seven to ten days.

How can meteorologists predict chaotic weather systems further in advance? They rely on the fact that while the climate is variable, it is possible to predict this variability by looking at larger-scale drivers.

In Australia, our climate is strongly influenced by drivers of variability such as the El Niño-Southern Oscillation, which have some predictability. This lends some accuracy to seasonal outlooks.

These climate drivers have their own seasonal cycles. This means there are times in the year when seasonal outlooks are more accurate than others. El Niño and the Indian Ocean Dipole both have strong relationships with Australia’s climate in spring. As a result, spring outlooks tend to be more accurate than predictions for other seasons.

Over summer, more of our rainfall comes from thunderstorms. That means rainfall is more variable between places even just a few kilometres apart and also less predictable. Overall, this makes seasonal predictions for summer much harder.

How’s summer shaping up?

While it is harder to forecast summer, we can watch the climate drivers to gauge what’s likely to happen.

When the El Niño–Southern Oscillation is in an El Niño phase, the climate tends to be hotter and drier. In a La Niña, the climate tends to be cooler and wetter. But it can also be in betweeen, or “neutral”, as it has been since April. It looks likely to stay neutral over summer, though there’s a chance it might develop into a weak La Niña event.

In summer, the Indian Ocean Dipole, which can bring rain to southeastern Australia in its negative phase, tends to weaken and have less influence on Australia’s climate.

Locally, the seas around Australia remain warmer than normal, which increases evaporation and makes more moisture available for rainfall.

Taken together, this is why the outlook is pointing towards wetter-than-normal conditions for much of Australia over summer. But we can’t be sure because when the ENSO climate driver is in the neutral phase, the effect on our weather is weaker.

In many places, there’s a roughly 2-in-3 chance of a wetter than average summer. But that means there is still a 1-in-3 chance of a drier than normal summer.

Accompanying the wetter summer outlook is a prediction for warmer nights and, to a lesser extent, warmer days. Night-time temperatures tend to be higher when there is cloud and rain.

Most seasonal outlooks point to warmer than average conditions these days. That’s partly because we’re comparing the coming season to the average of all the summers from 1981–2018. It was cooler then.

Remember, Australia’s climate has already warmed by 1.5°C since 1900.

A summer of fire for some?

The National Council for Fire and Emergency Services draws on the bureau’s long-range summer forecast to develop its own seasonal outlook of bushfire risk, which was also released today.

Such seasonal bushfire outlooks are also challenging to make. Complex combinations of weather and fuel (dry vegetation) characteristics shape whether a fire is likely to occur and spread if there is an ignition source (such as lightning). But these outlooks are important when planning for managing one of Australia’s major hazards. They are also useful in raising public awareness of fire risks as the southern Australia fire season gets under way.

Areas most at risk include Western Australia’s southeastern coastline, South Australia’s lower Eyre Peninsula around Port Lincoln, and the lower southeast including Mount Gambier, stretching over the border into southwestern Victoria around Horsham.

Parts of northeast Victoria and the Mornington Peninsula near Melbourne are also at higher risk, as well as northern and central southern New South Wales.

In northern Australia, the areas most at risk include long-unburnt areas in the southern half of the Northern Territory through to north of the Barkly Highway and across to the Queensland border.

Some of these areas are also regions where rainfall has been below normal in recent weeks and months. The continuing stormy conditions and potential for heavy rain over parts of Australia will hopefully reduce the risk of fires in these areas.

Be prepared

In any summer, parts of Australia will experience periods of extreme heat, risk of fires, and stormy weather that can bring hail and flooding rains. Being prepared for severe weather, keeping an eye on the forecast and following any weather warnings that are issued is important to minimise your risk.

Andrew King, Senior Lecturer in Climate Science, The University of Melbourne

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

Visiting a national park is good for our health and wellbeing. But the benefits are not shared equally across the community. Often the people who need it most are least able to access a high-quality dose of nature.

We wanted to quantify the benefit to the health system, in dollar terms. After all, health budgets are steadily growing while urban green spaces with high biodiversity are often degraded and squeezed by development.

Our new research puts a dollar value on the health benefits of visits to national parks within reach of the city of Adelaide in South Australia. We estimate every visit saves the health budget almost A$100 ($96).

Scaled up across the country, this means the 22 million day trips to national parks in 2019 could shave more than $2.1 billion off the nation’s health bill every year. This estimate assumes visits and benefits are similar across the country. It can pay to look after nature.

How did we estimate this?

Past research shows spending time in nature may reduce stress, depression, anxiety, obesity, type II diabetes, heart disease and lung disease. The health benefits of access to green space are often cited to support the conservation of biodiversity, particularly in cities.

But it’s hard to calculate the economic value of these benefits. There’s a lack of data on the number of people who benefit and it’s difficult to estimate how big the benefit is. For instance, how do you calculate the “dosage” of urban green space as a health treatment and measure the amount of health gained from a given dose?

To find out more, we examined the health benefits of access to nature in 20 national parks within 60 kilometres of central Adelaide over the 2018–19 financial year.

To work out how many people visited each park, and how far they travelled to get there, we used de-identified mobile phone “ping” data.

A ping is what happens when one of the apps on your phone sends a message to the nearest phone tower to check for updates. We obtained app ping data for each of the 20 national parks, which gave us the result of 1.45 million visitors over the 2018–19 year.

We combined the ping data with information from a survey of more than 1,000 park visitors about attitudes towards and use of South Australian parks. It was also combined with general Australian Institute of Health and Welfare data on South Australia’s population health.

We then estimated a health benefit from access to parks for citizens across various socioeconomic groups.

To work this out, we compared self-reported health rating data from people who did or did not visit these parks. This showed people who visit parks are much more likely to report their health as “very good” or “excellent” compared to those who don’t. We also looked at the shifts in health status for different socioeconomic groups.

We were able to control for the differences in underlying health of the people who answered the survey. This gave us a result: the difference in positive self-reported health between park visitors and those who don’t visit was between 2% and 5%.

We then used 2018-19 data on the cost of treating ten categories of major long-term chronic disease – such as diabetes, arthritis and cancer – to estimate savings to the health budget.

How much good does a visit do?

We analysed the health benefits of more than 1.45 million visits to national parks during the course of our study.

We found access to these green spaces could be worth $140 million a year in reduced healthcare costs. This is equivalent to around 4% of the total South Australian healthcare budget.

Dividing $140 million by 1,453,271 visits works out to $96 per visit.

Access to nature is not equal

We found people living in lower socioeconomic areas have to travel about three times as far to visit a national park than people in higher socioeconomic areas.

As a result, people from lower socioeconomic areas tend to make fewer visits to national parks. We found the number of visits for people from these areas was about 20% of the number of visits from people in higher socioeconomic areas.

This means the share of health benefits flowing to people in relatively disadvantaged areas is much lower. Health problems can have a greater financial impact for relatively socioeconomically disadvantaged people. So this group stands to benefit most from increasing access to nature, with greater potential savings for the health budget.

Spending on health and the environment

In total, Australia spent around $241.3 billion on health goods and services in 2021–22. That’s about $9,365 per person, on average. Health costs such as hospital spending continue to grow.

Commonwealth public hospital spending alone is expected to grow by $2 billion a year.

At the same time, spending on protecting nature makes up less than 0.1% of the Commonwealth budget and falls short of what Australians want. Almost all Australians (97%) want more action to prevent extinctions and more public investment to protect the environment and natural places (72%).

Our research suggests making nature more accessible by restoring urban biodiversity and increasing access to our protected areas can be a win for people, governments and the budget.

Health benefits for all

To fully realise and share these benefits, we need better integrated budgets which recognise how the natural world benefits our health and the broader economy. This requires being able to measure nature and our use of it in ways we have not been able to before.

Our research has attracted interest from policymakers in the recreation and wellbeing sectors. These sectors are becoming more prominent at the national level, as well as in South Australia, when it comes to valuing national parks and wildlife services.

As we come to better understand the relationships between contact with nature and health outcomes we stand a greater chance of investing well, and equitably, so everyone can benefit from improved physical and mental health.

Patrick O'Connor, Associate Professor in Natural Resource Economics, University of Adelaide; Adam James Loch, Associate Professor of Economics, University of Adelaide, and John Maclean, Lecturer in Data Science, University of Adelaide

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

This year will set a record for the addition of renewables to the grid, according to figures to be released on Thursday by the Clean Energy Regulator.

It projects the average annual renewable share of the electricity market will be 45% in 2025. The Albanese government’s target is 82% by 2030.

Total added capacity of renewables is expected to be 7.2 to 7.5 gigawatts in 2024, says the CER, which is responsible for accelerating carbon abatement.

Large scale power station approvals this year are expected to exceed a capacity of 4.2 GW, after the approval of Australia’s largest wind farm, MacIntyre wind farm in Queensland at 923 MW.

The new generation capacity is mainly wind (70%) and “will result in a material step up in the share of renewables as these new power stations reach full generation in the second half of 2025”.

An extra 1.2 GW of capacity has been applied for and is expected to be approved early next year.

The CER also expects a 3.15 GW increase in small-scale rooftop solar capacity.

The Australian Energy Market Commission, which makes the rules for the electricity and gas markets, will release residential energy price trends projecting that over the next decade residential electricity costs will decline, while delays to renewables would increase costs.

The AEMC suggests a household that is fully electrified could reduce its annual energy spending by 70% (or $3500 a year).

Energy Minister Chris Bowen will use his Thursday climate statement to parliament to warn against shifting course away from renewables, arguing they will bring down prices.

In a speech released in part ahead of delivery, Bowen says the AEMC data confirms that more renewables in the system “will continue pushing energy bills down over the next ten years”.

He says the Clean Energy Regulator “is explicit in its finding that delays to renewables would in fact increase costs”.

Bowen says just under half of the 7.5 GW new renewable capacity “will come front rooftop solar, a sign that households and businesses are getting real value from the economic benefits that come when you harness free sunshine”.

He says the “world-beating uptake” means there is now more rooftop solar capacity in the system “than the entire fleet of coal-fired power stations across the country.

"That means households and businesses are winning on two fronts – looking after our future generations by bringing down emissions, and bringing down power bills today, and for years to come.”

“Suggestions that Australia should turn its back on advancements such as these and revert to a system dominated by fossil fuels will be the nail in the coffin to Australia reaching net zero by 2050.”

With a burst of hot weather this week, the NSW government on Wednesday urged businesses and households to conserve power between 3pm and 8pm. It suggested delaying the use of non-essential appliances such as dishwashers and pool pumps and if possible setting air conditioners to a higher temperature.

This followed the Australian Energy Market Operator forecasting there could be insufficient generation available to meet demand.

Questioned in parliament, Bowen played down the situation saying it was “not an unusual circumstance”.

Michelle Grattan, Professorial Fellow, University of Canberra

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

This year’s humpback whale (Megaptera novaeangliae) season in Australia has almost come to an end. The beloved mammals are on their way to Antarctica for a summer of feeding. Next year from April onwards, millions of people will again witness their movements and acrobatic displays – either from the coast or by joining one of the hundreds of whale-watch boat operators.

But as much as we like to watch humpback whales, we still know very little about them. They are notoriously difficult to study in the field. While they are known for their surface activities, they spend most of their time underwater and outside the range of direct observations.

One of the biggest mysteries of all is how these animals make decisions to determine what they do and where they go.

This is where our new research, published in Marine Mammal Science today, comes in. We developed a model which effectively captures key humpback whale behaviours and their resulting southward migratory movements in east Australia. It can help anticipate challenges whales may face in the future. In turn, it may aid efforts to better conserve these majestic animals.

A comeback

Following the end of commercial whaling, the worldwide recovery of humpback whale populations has been very successful. In Australia, the species was removed from the threatened species list in 2022.

However, scientists fear the effects of climate change may now be the biggest threat to their survival.

Our previous research examined which environmental factors matter in humpback whale ecology. For instance, while water temperature may have little impact in the cold Antarctic waters, breeding grounds further north that are too warm could drive humpback whales to seek better conditions elsewhere.

Currently we rely on satellite tags to inform us of their large-scale whereabouts. But unfortunately, this provides little information on humpback whale activities on a smaller scale, such as how they socialise, hunt, or react to specific conditions.

Movements through space and time

To address this, we turned to computer models, as these can deal with scarce or inconsistently collected data. In particular, “agent-based” models are designed to capture the behavioural response of an agent (in this case, a pod consisting of a humpback whale mother and one calf) to the environmental conditions they encounter. Based on this information, the models then project movements through space and time.

We developed the first such model to simulate migratory movements of humpback whale mother and calf pods between the Great Barrier Reef and the Gold Coast bay. Along this route is Hervey Bay, an important resting area due to its calm and sheltered waters, where the pairs may stay for up to a few weeks before continuing migration.

As humpback whales are almost always sighted in waters between 15 and 200 metres deep and below 28°C, we took a simple yet reasonable approach where we assumed they avoided waters too shallow, deep, or warm as they swam southwards.

This “avoidance” response would be similar to us going indoors when it is too hot outside or raining heavily: a simple decision to move away from somewhere we are not comfortable.

A combo of current and swimming speed

To estimate how fast whales were moving, we combined the speed of the current with an estimate of real-world swimming speeds by migrating mother and calf pairs along the Gold Coast.

Our simulations accurately predict the routes taken by migrating mother and calf pairs but point to a change in direction after Hervey Bay so whales remain close to the coastline.

Other research has shown that this “distance to shore” is an important variable to consider when studying humpback whales.

Results also highlight the importance of water depth when entering Hervey Bay and ensuring the whales avoid getting too close to shore or into the deep ocean.

A tool for conservation

What the model does less well is accurately predict travel time between the Great Barrier Reef and the Gold Coast bay.

There are a few reasons why this may be the case. For example, the aforementioned underwater movements and associated behaviours are difficult to capture and convert into meaningful components of our model. Research has started to reveal detailed dive profiles but is time consuming and expensive.

We also assume that swimming speed remains more or less constant over time regardless of whether it is day or night. However, research into daily activity patterns has, so far, focused primarily on feeding and mating behaviours rather than variations in swimming speed.

Nevertheless, the current version of our model provides a suitable framework for simulating humpback whale migration and can be expanded to investigate a response of this species to future changes in ocean conditions. In theory, it can be applied to other marine species too, as long as relevant behavioural response data is available.

The development of such predictive models is increasingly important to aid conservation efforts and guide effective strategies for protecting vulnerable species affected by climate change.

Jasper de Bie, Research Fellow, Coastal and Marine Research Centre, Griffith University

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

Earlier this week, the mining magnate Andrew Forrest made headlines calling for a global “polymer premium” – or plastic tax – to be placed on every tonne of newly manufactured plastics. A tax like this could form part of the Global Plastic Treaty being hammered out right now in Busan, South Korea. In fact, a treaty aimed at stopping plastic waste will have to have strong measures such as a plastic tax or a cap on plastic production to shift the status quo.

In economics, taxing things you don’t want should mean fewer get made. What Forrest is pitching is a way to curb the seemingly unstoppable rise in plastic production and tackle the plastic waste crisis at its source. While we may think recycling is all we need to solve the plastic waste problem, it’s nowhere near enough. Plastic is steadily choking seas and rivers, while toxic microplastics damage our health.

Forrest isn’t the first. Environmental groups and think tanks are also calling for a global tax on plastic producers and importers.

Many plastic products are designed to last for a long time. But manufacturers are increasingly churning out cheap plastics such as single-use items and food packaging which almost inevitably become waste.

Introducing a tax would add an additional cost to making virgin (new) plastic, to deter manufacturers from producing and selling as much non-recyclable and non-reuseable products as possible. If introduced, they would go some way to cut the overproduction of plastic.

What would a plastic treaty do?

Over this week and next, negotiators from more than 170 United Nations member states are working towards a Global Plastic Treaty at the fifth and final set of talks.

Work on this treaty has progressed rapidly. It was only in 2022 that 175 nations voted to adopt a historic resolution to negotiate a legally binding international treaty to end plastic pollution. In recognition of the danger posed by unchecked plastic production, nations set an accelerated timeline. If a treaty is agreed, it could come into effect as soon as 2025.

It would operate much like the legally-binding Paris Agreement on climate change, which requires nations to regularly report their greenhouse gas emissions and efforts to cut them. A Global Plastics Treaty would include binding measures requiring signatories to commit to action on plastic pollution. But exactly what will be covered and how is yet to be decided.

Nations have already agreed on measures to improve waste management and recycling as well as new design standards for plastic products.

While positive, the hardest part is yet to come.

These final negotiations wraps up on Sunday. Still to come is a decision on the most contentious issue: whether to introduce limits on how much plastic a company can produce. Plastic industry lobbyists are arguing strongly against any cap to plastic production.

Recycling isn’t enough

Plastic pollution has been a problem for decades. But to date, our efforts to respond have hardly made a dint. Today, there are about 7 billion tonnes of plastic waste in the world. So far, just 9% has been recycled.

The rest ends up burned in incinerators, in landfills, or in rivers, seas and forests. Plastics can also damage our health in many different ways.

Plastic production doubled between 2000 and 2019, reaching 460 million tonnes a year. By 2060, production is projected to almost triple that figure, to 1.2 billion tonnes a year.

An increasing proportion of plastic production is single-use packaging, which is cheap to make and almost impossible to recycle.

Researchers have found recycling and waste management will only cut plastic pollution by 7% in the long term. These tools won’t be enough.

Plastic taxes are not new

In 2021, the European Union introduced a levy on non-recycled plastic packaging waste created by its member states. Set at €0.80 (A$1.30) per kilo, the cost is borne by national governments, who in turn can pass the cost on to producers. The levy is expected to generate A$11.3 billion per year when fully implemented.

Nations in Europe have already begun to pass on the cost. Last year, Spain imposed a tax on producers and importers of single use plastic packaging, while Hungary expanded an existing scheme to include plastic products. Earlier this year, Bulgaria, Portugal and the United Kingdom introduced their own fees for single-use plastics.

Because these taxes are new, it’s difficult to fully assess their impact. But over time, these incentives should reduce plastic pollution and boost government revenue, which can be used to drive better recycling and resource recovery.

Australia’s government is consulting on new standards for packaging in a bid to phase out dangerous chemicals and boost use of recycled plastics, while some state and territory governments have introduced bans on single-use plastics. But plastic waste researchers and environmental advocates argue that stronger measures are needed to curb plastic waste.

Taxing single-use plastic packaging in Australia could raise $1.5 billion, according to one study. These funds could be used to accelerate progress on plastic pollution.

A global treaty needs teeth

Over the last 70 years, plastics have become ubiquitous. But the convenience of cheap plastics comes at a cost to our health and the health of the natural world.

Tackling plastic pollution will take concerted effort and financing to reduce plastic production.

As Andrew Forrest and others point out, taxing virgin plastic could discourage overproduction of plastics and encourage more investment in recyclable and reusable plastic products.

But for plastic taxes to work, they need to be widely adopted. That could be as part of the Global Plastic Treaty, or done on a national level. Plastic taxes could work as an alternative to capping plastic production, if negotiators can’t reach agreement in Busan.

Plastic taxes are not a silver bullet. We would still need a suite of measures addressing plastics throughout their lifecycle, from design and production to recycling and disposal. But putting a price on plastic would help.

Amelia Leavesley, Research Fellow in Urban Sustainability, The University of Melbourne

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

Extreme temperature and rainfall events are increasing around the world, including Australia. What makes them extreme is their rarity and severity compared to the typical climate.

A region’s “climate” is defined by a 30-year average of mainly rainfall and temperature. Increasingly, these climate definitions have become less appropriate – we need to look at events over shorter time periods to gain a more accurate picture.

We can see this in the recent worldwide proliferation of extreme flooding and prolonged heatwaves.

Using southern Australia as a prime example, our newly published research in Academia Environmental Sciences and Sustainability shows that machine learning techniques can help identify key climate drivers, supporting a redefinition of climate in a warming world.

Increasing ‘flash’ events

In Australia, eastern coastal regions of Queensland and New South Wales continue to receive record downpours and flash floods, interspersed by dry periods of a few months to a few years.

In stark contrast, southern coastal regions are drying and facing more extreme heatwaves. With already parched vegetation and catastrophic fire dangers, this region is experiencing drought conditions due to decreased cool season rainfall and increased temperatures.

Notably, flash droughts and flash floods have adversely affected both agricultural crop yields and grazing pasture quality. Flash droughts greatly reduce moisture for germination. Flash floods ruin crops close to harvest time.

The problem with these “flash” events is just how difficult they are to forecast. To make more accurate seasonal and annual predictions for rainfall and temperatures, we need to update our climate models. But how do we know which climate drivers need to be included?

Seeking a new normal

To keep track of typical climate conditions and provide context for weather and climate forecasts, the World Meteorological Organization uses a set of data products known as climatological standard normals.

They define climate as averages of monthly, seasonal and annual weather-related variables such as temperature and rainfall, over consecutive 30-year periods.

Climate normals can be used to assess how typical of the current climate a particular event was in a given location. It’s how we arrive at temperature anomalies.

For example, to tell whether a year was relatively “hot” or “cool”, we look at the anomaly – the difference between the average temperature for the calendar year in question, compared to the climate normal.

But extreme variations are now occurring in periods of ten years or even shorter. Consequently, multiple increases and decreases can cancel each other out over a 30-year period. This would hide the large changes in statistics of weather variables within that period.

For example, large rainfall changes in average monthly, seasonal and annual amounts can be hidden within 30-year averages. Global warming often amplifies or diminishes the impacts of multiple climate driver phases within approximately ten-year periods. When averaged over 30 consecutive years, some information is lost.

What did we find?

Over the past decade or so, machine learning (where computers learn from past data to make inferences about the future) has become a powerful tool for detecting potential links between global warming and extreme weather events. This is referred to as attribution.

Machine learning techniques are simple to code and are well-suited to the highly repetitive task of searching through numerous combinations of observational data for possible triggers of severe weather events.

In our new study, machine learning helped us untangle the dominant climate drivers responsible for recent flash flood rainfall on the east coast of Australia, and a lack of rainfall on the southern coast.

Along the southern coast, the cool season from May to October is typically produced by mid-latitude westerly winds. In recent years these winds were farther away from the Australian continents, resulting in the recent drought of 2017–19 and flash drought of 2023–24.

In contrast, after the 2020–22 La Niña, the east coast continues to experience wetter conditions. These come from generally higher than average sea-surface temperatures off the east coast and Pacific Ocean, due to the presence of onshore winds.

Machine learning identified the dominant drivers of the scenario above: the El Niño-Southern Oscillation, the Southern Annular Mode, the Indian Ocean Dipole, and both local and global sea surface temperatures.

A key finding was the prominence of global warming as an attribute, both individually and in combination with other climate drivers. Climate drivers and their combinations can change with increasing global warming over shorter periods that contain extremes of climate. Hence, the use of 30-year periods as climate normals becomes less useful.

Finding regional attributes for better forecasting

Climate models often disagree on the climate drivers likely to be relevant to extreme events.

A key feature of machine learning is the ability to deal with multi-source data by identifying regional attributes. We can combine possible climate-driver predictors with high-resolution climate model predictions, especially after the climate model data are downsized to cover specific regions of concern. This can help with extreme event forecasting at a local scale.

Scientists are continuously developing new methods for applying machine learning to weather and climate prediction.

The scientific consensus is that global warming has dramatically increased the frequency of extreme rainfall and temperature events. However, the impacts are not uniform across the world, or even across Australia. Some regions have been more affected than others.

Currently there is no single alternative definition to the traditional 30-year climate normal, given the variable impacts across the planet. Each region will need to determine its own relevant climate time period definition – and machine learning tools can help.

Milton Speer, Visiting Fellow, School of Mathematical and Physical Sciences, University of Technology Sydney and Lance M Leslie, Professor, School of Mathematical And Physical Sciences, University of Technology Sydney

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

Many people long involved in global climate negotiations see the annual United Nations COP climate talks as fundamentally flawed. That includes me.

On Sunday, the 29th round of talks finished in Baku, Azerbaijan. It was likely my 25th COP. I have attended these talks in many different roles, but largely as a climate negotiator for the Australian government. These days I attend in my academic capacity.

COP29 did not achieve a breakthrough. It led to a modest increase in climate finance for developing nations and agreement on carbon market rules. But many issues were kicked down the road.

COP talks are slow. And the once-a-year meetings are seen as “win or lose” moments, which complicates the dynamics. Oil states and lobbyists work to avoid mention of quitting fossil fuels. Host nations need a win, leading to “commitments” which may not lead to substantive change. Ahead of this year’s talks, major climate figures called once more for reform to the COP process.

But however flawed, COP meetings are the only way to get the world’s nations in the same room to hash out what to do about climate change.

In recent years, global leaders have been distracted by COVID, the Ukraine-Russia war and now the Middle East. But climate change is only worsening. It won’t be long before real world events pull our attention back to the single largest threat we face.

Why do these talks matter?

Since 1995, the COP talks have acted as the main driver of global action on climate change. These talks will continue to matter until the transition to clean energy is complete and the burning of fossil fuels is no longer routine.

Climate change has a one-word solution: investment. Every day, companies and governments invest money. They either invest it in status quo technologies which make carbon pollution worse, or they invest in cleaner alternatives.

What the COP talks do is help change the direction of investment. You can see this working very clearly in how much is now being invested in green energy, electricity grid upgrades and energy efficiency – double that for new fossil fuels. (Unfortunately, if you include fossil fuel subsidies, the picture is very different.)

Last year, nations finally included text about the need to transition away from fossil fuels. It was hard-won. But this year, diplomats from Saudi Arabia and petrostate allies were able to block any mention of this.

The text on fossil fuels was not binding. But it was influential in boardrooms where decisions on investment are made.

Process over progress?

The way the COP talks are set up are not ideal.

A new country is chosen every year to take on the presidency role and host the summit. The talks run for a fortnight and the agenda is vast. This year, the hosts, Azerbaijan, struggled to keep control of the agenda. As a result, issues such as the Global Stocktake – which included the calls to quit fossil fuels – were kicked down the road to COP30 in Brazil in a year’s time.

Because these talks are just once a year, everything crowds into them. It is very messy.

Every June, climate negotiators meet for an inter-sessional meeting before the next COP talks in Bonn, Germany, where the UN Secretariat on Climate Change has its headquarters.

At these meetings, we often see efforts to walk back announcements made at the formal COP talks. Sometimes these are successful.

Every delegate sent to COP talks has two reasons for going. The first is because their government is to some extent committed to solving the great problem of climate change. Five or six nations might not be, but that leaves over 190 who are. The second reason is to protect their national interests. You can, of course, do both.

But this brings up a hidden issue. Many people who attend become, in my view, focused on the process, not the outcome. Twice a year, they travel to the COP itself and the Bonn intersessional, where they will meet friends and colleagues. It has become routine. The process has become, for some, the point.

Five ideas for change

COP talks are flawed but necessary. Could we improve them?

Here are five ideas:

1. Break up the negotiating process

Meetings of COP subsidiary bodies in cities where most nations have established diplomatic missions. These bodies could meet more regularly, creating pressure and momentum for more speed and outcomes.

2. Change COP presidency arrangements

At times, the nation hosting the talks tries to control outcomes as much possible. But this is an all but impossible task. A better option might be to rely on the negotiators from each nation who do most of the work – and make them accountable for achieving outcomes.

3. Make regional meetings more important

COP is big. Hundreds of countries, thousands of delegates, and many from civil society and business. It’s very difficult when everyone tries to talk to everyone. Much better progress would come if the thrust of COP talks was devolved to smaller, more regular regional meetings.

4. Gather more ambitious countries

There have been several gatherings of nations wanting to do more, faster on climate change, such as the High Ambition Coalition. These gatherings can help stimulate action among like-minded leaders. But they need sustained leadership to be effective.

5. Direct action by the largest emitters

In 2015, the Paris Agreement set a joint goal of keeping climate change below 2°C. It was the high water mark for COP talks. Before this agreement was signed, top emitters China and the United States found common ground on climate in direct talks, despite intensifying geopolitical jostling. This helped Paris succeed. In 2025 under President Donald Trump, the US will walk off the climate action stage again. But China is now feeling more confident in shouldering a climate leadership role.

What about preventing oil states from hosting these talks, as prominent climate movers and shakers have called for? You can’t easily shut out countries who have signed treaties and agreements. The solution here is to organise better. Oil-state pressure doesn’t have to win. While oil rich Azerbaijan’s presidency of COP29 drew scepticism, there was no sign that its leaders wanted the process to fail.

Needed: renewed political will

Ten years ago, it felt like the world was largely united on climate. But while the Paris Agreement has helped avert the worst emissions scenarios, it has not yet led to a single year of declining emissions.

Climate change has, by any measurement, slipped down the global list of urgent issues. That will change as more calamitous impacts arrive.

Howard Bamsey, Honorary Professor, School of Regulation and Global Governance, Australian National University

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

Negotiators at the COP29 climate conference in Baku have struck a landmark agreement on rules governing the global trade of carbon credits, bringing to a close almost a decade of debate over the controversial scheme.

The deal paves the way for a system in which countries or companies buy credits for removing or reducing greenhouse gas emissions elsewhere in the world, then count the reductions as part of their own climate efforts.

Some have argued the agreement provides crucial certainty to countries and companies trying to reach net-zero through carbon trading, and will harness billions of dollars for environmental projects.

However, the rules contain several serious flaws that years of debate have failed to fix. It means the system may essentially give countries and companies permissions to keep polluting.

What is carbon offsetting?

Carbon trading is a system where countries, companies or other entities buy or sell “credits”, or permits, that allow the buyer to offset the greenhouse gas emissions they produce.

For example, an energy company in Australia that produces carbon emissions by burning coal may, in theory, offset their impact by buying credits from a company in Indonesia that removes carbon by planting trees.

Other carbon removal activities include renewable energy projects, and projects that retain vegetation rather than cutting it down.

Carbon trading was a controversial part of the global Paris climate deal clinched in 2015.

The relevant part of the deal is known as “Article 6”. It sets the rules for a global carbon market, supervised by the United Nations, which would be open to companies as well as countries. Article 6 also includes trade of carbon credits directly between countries, which has begun operating even while rules were still being finalised.

Rules for carbon trading are notoriously complex and difficult to negotiate. But they are important to ensure a scheme reduces greenhouse gas emissions in reality, not just on paper.

A long history of debate

Over the past few years, annual COP meetings made some progress on advancing the carbon trading rules.

For example, COP26 in Glasgow, held in 2021, established an independent supervisory body. It was also tasked with other responsibilities such as recommending standards for carbon removal and methods to guide the issuing, reporting and monitoring of carbon credits.

But the recommendations were rejected at COP meetings in 2022 and 2023 because many countries viewed them as weak and lacking a scientific basis.

At a meeting in October this year, the supervisory body published its recommendations as “internal standards” and so bypassed the COP approval process.

At this year’s COP in Baku, the Azerbaijani hosts rushed through adoption of the standards on day one, prompting claims proper process had not been followed

For the remaining two weeks of the conference, negotiators worked to further develop the rules. A final decision was adopted over the weekend, but has attracted criticism.

For example, the Climate Land Ambition and Rights Alliance says the rules risk “double counting” – which means two carbon credits are issued for only one unit of emissions reduction. It also claims the rules fail to prevent harm to communities – which can occur when, say, Indigenous Peoples are prevented from accessing land where tree-planting or other carbon-storage projects are occurring.

Getting to grips with carbon removal

The new agreement, known formally as the Paris Agreement Trading Mechanism, is fraught with other problems. Most obvious is the detail around carbon removals.

Take, for example, the earlier scenario of a coal-burning company in Australia offsetting emissions by buying credits from a tree-planting company in Indonesia. For the climate to benefit, the carbon stored in the trees should remain there as long as the emissions produced from the company’s burning of coal remains in the atmosphere.

But, carbon storage in soils and forests is considered temporary. To be considered permanent, carbon must be stored geologically (injected into underground rock formations).

The final rules agreed to at Baku, however, fail to stipulate the time periods or minimum standards for “durable” carbon storage.

Temporary carbon removal into land and forests should not be used to offset fossil fuel emissions, which stay in the atmosphere for millennia. Yet governments are already over-relying on such methods to achieve their Paris commitments. The weak new rules only exacerbate this problem.

To make matters worse, in 2023, almost no carbon was absorbed by Earth’s forests or soils, because the warming climate increased the intensity of drought and wildfires.

This trend raises questions about schemes that depend on these natural systems to capture and store carbon.

What next?

Countries already can, and do, trade carbon credits under the Paris Agreement. Centralised trading will occur under the new scheme once the United Nations sets up a registry, expected next year.

Under the new scheme, Australia should rule out buying credits for land-based offsets (such as in forests and soil) to compensate for long-lasting emissions from the energy and industry sectors.

Australia should also revise its national carbon trading scheme along the same lines.

We could also set a precedent by establishing a framework that treats carbon removals as a complement — not a substitute — for emissions reduction.

Kate Dooley, Senior Research Fellow, School of Geography, Earth and Atmospheric Sciences, The University of Melbourne

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

The petroleum-laden dust has settled on this year’s United Nations climate summit, COP29, held over the past fortnight in Baku, Azerbaijan. Climate scientists, leaders, lobbyists and delegates are heading for home.

The meeting achieved incremental progress. Negotiators agreed on a new climate finance target of at least US$300 billion a year by 2035 (A$460 billion), up from US$100 billion now. These funds would help developing nations shift away from fossil fuels, adapt to the warming climate and respond to loss and damage from climate disasters.

Nations also agreed on the essential rules for a global carbon trading market, the last agreement needed to make the 2015 Paris Agreement fully operational.

As UN climate chief Simon Stiell said in the final session, the 29th Conference of the Parties (COP29) meeting showed the Paris Agreement was delivering on climate action, but national governments “still need to pick up the pace”.

I attended COP29 as an expert in international climate law and litigation. I observed the finance negotiations firsthand and represented a new alliance of Australian and Pacific universities supporting international climate cooperation.

At the outset, expectations for the conference were low. The United States had just voted for the return of climate denier Donald Trump. And Azerbaijan President Ilham Aliyev declared oil and gas a “gift of God” at an opening event.

But even with these considerable headwinds, progress was made.

Progress on climate finance

The world’s rich countries currently contribute US$100 billion a year to climate finance for developing nations. It pays for measures to reduce greenhouse gas emissions and adapt to climate change by making systems more resilient.

Two years ago, countries agreed to create a new “loss and damage” fund for nations dealing with climate disasters, launched at the summit in Dubai last year.

At these COP29 talks, Australia announced it would contribute A$50 million (US$32 million) to this fund. Climate change is already costing developing countries huge sums, estimated at US$100-$500 billion a year.

These flows of funding from rich countries are essential for developing nations to increase their emissions reduction, as well as respond to climate damage.

The COP29 deal sets a target of at least US$300 billion per year by 2035, with richer countries leading delivery.

While this goal represents a tripling of the previous target, it falls far short of the $400-$900 billion many developing countries had called for in finance from rich governments.

Disappointed developing country representatives labelled it “a paltry sum” and a “joke”. It also falls short of what experts say is needed by 2035 to meet global climate finance needs.

Recognising this gap, the text calls on “all actors to work together” to scale up finance from all public and private sources to at least US$1.3 trillion per year by 2035. Ways this might be achieved will be presented at COP30 in Belém, Brazil, a year from now.

Making the international carbon market a reality

COP29 also reached an agreement that settles longstanding disputes about making the international carbon market a reality. This hard-won deal delivered global standards for carbon trading, opening up new ways for developing countries to boost their renewable energy capacity.

These rules will pave the way for country-to-country trading of carbon credits. Each credit represents a tonne of carbon dioxide either removed from the atmosphere or not emitted. The deal will give countries more flexibility in how they meet their emissions targets.

It’s not perfect. Concerns linger on whether the rules will ensure trades reflect real projects and how transparent and accountable the market will be.

But the agreement will boost the importance of carbon credits and could increase incentives to protect carbon “sinks” – such as rainforests, seagrass meadows and mangroves – with flow-on nature benefits.

New national climate goals

By February 2025, all 195 Paris signatories have to announce more ambitious emission targets. Some countries announced their new plans at COP29.

The most ambitious was the United Kingdom, which upped its 2030 goal of a 68% cut to reducing 81% below 1990 emissions by 2035.

Next year’s host, Brazil, released new targets for a 59%–67% drop below 2005 levels by 2035.

But Brazil didn’t amend its 2030 ambitions and plans to boost oil and gas production 36% by 2035.

The United Arab Emirates announced target cuts of 47% before 2035, ahead of net zero by 2050. But this pledge was criticised by climate campaigners because the UAE is projected to boost oil and gas production 34% by by 2035.

The host, Azerbaijan, did not release its goals. Many other countries, including Australia, also held off from announcing new targets in Baku.

Indecision on fossil fuels

Fossil fuels were the elephant in the room. At last year’s COP in Dubai, nations finally agreed to include wording on:

transitioning away from fossil fuels in energy systems, in a just, orderly and equitable manner, accelerating action in this critical decade, so as to achieve net zero by 2050 in keeping with the science

But at this year’s COP, there was no decision on how, exactly, to begin this transition – and fossil fuels are not explicitly mentioned in the outcome documents.

Delegates from oil giant Saudi Arabia repeatedly tried to block mention of fossil fuels across all of the negotiating streams.

Trump’s return wasn’t a deal-breaker

The consequences of Trump’s re-election for climate action were much discussed. But I observed a surprising amount of acceptance and even optimism for climate cooperation.

The US is the world’s second-largest emitter, after China. Trump has promised to ramp up the country’s oil and gas production, and pull the US from the Paris Agreement as he did during his first term.

But climate action continued regardless – especially in renewables giant China, which hit its 2030 renewable target this year. The US is no longer the main player in climate negotiations, and many countries are much further down the road of cutting emissions. Few show signs of backtracking.

As the US bows out, it creates a vacuum. At COP29, middle powers such as Canada, the UK and Australia stepped up.

Negotiators from a progressive High Ambition Coalition – including small island states, the European Union and Latin American countries such as Colombia – played an important role in pushing to urgently increase finance for climate action.

China, for its part, is clearly eyeing off the position of climate leader about to be vacated by the US. And leaders of progressive US states attended COP29 to show parts of the US are still on board with climate action.

Australia’s hosting bid for 2026 talks in limbo

Australia’s bid to host COP31 in 2026 alongside Pacific nations was tipped to win, given it had the support from nearly all of the 29 “Western European and Other States” group of nations which will decide the host this time. Many observers expected an announcement at the end of COP29.

But no decision was made, as the rival bidder, Türkiye, did not withdraw its bid.

An announcement is now likely in mid-2025 – after Australia’s next federal election.

What now?

Many people are disappointed by COP29. It did not bring transformative change. The huge jump in climate finance called for by developing countries, and many in civil society, didn’t eventuate.

It came as 2024 is on track to be the hottest on record, and the costs of extreme weather have risen to more than US$2 trillion over the last decade.

But this year’s talks were still a step forward, affirming international climate cooperation at a time of significant geopolitical tensions globally. As the UN’s Simon Stiell said:

the UN Paris Agreement is humanity’s life-raft; there is nothing else […] We are taking that journey forward together.

Jacqueline Peel, Director, Melbourne Climate Futures, The University of Melbourne

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

In humans and other animals, ageing is generally associated with a decline in biological function. But scientists are now discovering older animals perform vital roles in populations and ecosystems.

Unfortunately, however, old animals can suffer the most from human activity such as over-fishing and trophy hunting. And the value of old, wise animals is not usually considered when we manage animal populations and seek to protect biodiversity.

Our new review, published today in Science, draws on evidence from around the world to argue for a new approach called “longevity conservation”.

The loss of old and wise animals has devastating global consequences. Clearly, more must be done to prioritise their survival.

Benefits of a long life

Cold-blooded (ectothermic) animals such as fish and reptiles tend to keep growing throughout their life. This means older individuals are generally larger than younger individuals.

Being bigger has benefits, especially when it comes to feeding and reproduction. It’s widely known the number of offspring increases with age in fish and many other ectotherms. But it’s only recently been discovered that older mothers of some fish and sea turtles produce exponentially more offspring as time goes on. Their young may also have better chances of survival.

Survival rates are can be higher in offspring from older mothers in other species too. For example, in birds older parents and their helpers often provide more food and better habitat for their chicks, improving fledgling survival rates.

Females from a range of species tend to select older males as mates. These males commonly assume crucial social roles, such as leading long distance movements like migration, and regulating social structures, such as reducing aggressive behaviour. These behaviours influence decision-making with direct consequences for group and offspring survival.

With age comes wisdom

Some animals draw on experience accumulated over the course of their lifetime in order to make better decisions. In elephants, mothers and grandmothers are repositories of knowledge.

This “grandmother effect”, first studied in humans, also occurs in whales. Wise grandmother killer whales, which no longer reproduce, help their families find food when it is scarce and this benefits survival.

In a wide range of species, new research is showing how older individuals transmit their knowledge to others via a process called cultural transmission. The benefits of old age extend to animals such as migratory birds, pack-hunting carnivores, and even fish. For example, taking all the big fish from some populations has diminished their collective group memory often needed for migration and knowledge of spawning areas.

Examining the loss of older animals

Our research set out to build understanding of the ecology and conservation of old animals.

We assembled an interdisciplinary team of experts who work on different animals and diverse ecosystems. Our team included behavioural and wildlife ecologists as well as freshwater, marine and fisheries scientists.

We searched the literature and wrote a review. In addition, we used a machine learning topic model to delve into more than 9,000 peer-reviewed papers.

Most research has focused on the negative aspects of ageing, particularly in humans, and short-lived animal models such as fruit flies. Yet emerging evidence is showing how old wild animals contribute to populations and ecosystems.

Many of these functions benefit people too, but are being lost as old individuals are removed from the wild.

Fishing has caused a systematic decline in the abundance of old fish, with these aged individuals reduced in 79-97% of the ocean populations examined.

Old African elephants and other trophy animals are commonly poached or hunted, both legally and illegally.

But the loss of old individuals is not limited to large enigmatic species. Deep-sea coral and Antarctic sponges – which can live for thousands of years – are being harvested, damaged by fishing gear, and affected by climate change. These species cannot be replaced within our lifetime.

Species that live to advanced ages are often large, slow-growing, and slow to mature. These traits can make these species more vulnerable to extinction if older adults are killed by humans.

But when humans spare old individuals, these long-lived species are more resistant to environmental change and provide more stable ecosystem services, such as fisheries which supply protein to feed the world.

Retaining old animals tends to protect populations from poor environmental conditions such as drought and other extreme climate events, allowing species to persist against the odds. This buffering capacity is increasingly important in the face of global climate change.

Introducing ‘longevity conservation’

Old animals play vital roles in the maintenance of biodiversity and ecosystem services.

Yet harvest management and conservation practices tend not to focus on preserving age structures within populations. And the loss of old individuals is not yet recognised by the International Union for Conservation of Nature as a means of listing threatened species, or as a type of over-fishing.

To protect old individuals and maintain or restore the age structure of wild populations, we propose “longevity conservation” measures.

Decisive new policy and actions are needed to protect and restore the crucial ecological roles and services old, wise, and large animals provide. For example, formally recognising and avoiding “longevity overfishing” should be incorporated into fisheries management to help ensure the long-term sustainability of fisheries.

Biodiversity conservation and threatened species policies should protect age structure. This is particularly important in long-lived species that produce more offspring with age, or where migration, social networks and cultural transmission of knowledge are required for survival.

Keller Kopf, Senior Lecturer in Ecology, Charles Darwin University

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

Imagine you are a blue whale swimming up the California coast, as you do every spring. You are searching for krill in the Santa Barbara Channel, a zone that teems with fish, kelp forests, seagrass beds and other undersea life, but also vibrates with noise from ship traffic. Suddenly, the noise gets louder.

You start to make a slow, shallow dive, but without much urgency – after all, your species evolved over millions of years without this mysterious noise, so why would you know what to do when you hear it? A minute later, you are fatally struck by a container ship.

Your body slowly sinks to the bottom of the ocean, where it will nourish deep-sea creatures for decades but will never be seen by humans again. Indeed, your death goes unnoticed; the vessel barely registers the impact of hitting a member of the largest animal species on Earth.

Collisions with ships are a critical threat to many large whale species. While these events are difficult to study, scientists estimate that thousands of whales are killed by ships yearly. In some regions, whales die from vessel strikes at rates that exceed what is considered sustainable after decades of whaling. Collisions with vessels threaten some critically endangered species.

Research and experience show that simple measures can reduce these collisions – for example, rerouting shipping lanes to avoid important areas for whales, or reducing vessel speeds. But to implement these interventions, scientists and policymakers need to know where whales are most at risk.

Mapping risk to whales

In a newly published study in Science, colleagues and I mapped global ship-strike risk for four species of Earth’s largest whales: blue, fin, humpback and sperm. Within each species’ range, we found that vessels traveled the equivalent of thousands of times the distance to the moon and back every year.

Our maps reveal widespread risk of vessel collisions in areas including the U.S. West Coast, the Mediterranean Sea and the northern Indian Ocean. These zones already have documented high levels of ship strikes.

We also found many other regions with similar levels of risk that are less studied and recognized. They include several stretches along the coastlines of South America and southern Africa, and the area around the Azores off the coast of Portugal.

Most high-risk areas are unprotected

Whales are largely unprotected from vessel collisions around the world. We identified collision-risk hot spots – areas in the top 1% of predicted risk globally that represent the riskiest places for each species.

We found that fewer than 7% of collision-risk hot spots had put measures in place to reduce collisions, such as limiting vessel speeds or requiring ships to avoid certain areas. Exceptions include the west and east coasts of North America, as well as the Mediterranean, which have higher levels of ship-strike management.

Where such measures exist, they often are voluntary. Mandatory restrictions on speed cover just 0.54% of collision-risk hot spots for blue whales, 0.27% for humpback whales and none of the hot spots for fin or sperm whales.

For each species, we found that ship-strike risk was higher within exclusive economic zones – areas up to 200 nautical miles from coastlines, in which each country has exclusive jurisdiction over marine resources – than on the high seas. This can make it easier to implement conservation and management measures in these areas.

Within exclusive economic zones, individual countries can either adopt voluntary vessel measures or propose mandatory changes through the International Maritime Organization, which regulates international shipping. There is a lot of opportunity for countries to protect whales in their national waters.

However, since political boundaries mean nothing to whales, the most effective approach would be for neighboring countries to coordinate efforts to reduce ship-strike risk across whale migratory routes.

We also found high levels of ship-strike risk within existing marine protected areas – zones where countries have adopted various measures to conserve and manage sea life. Most of these marine protected areas were created to protect sea life from fishing, but very few place any restrictions or regulations on shipping. When marine protected areas contain high levels of ship-strike risk, governments could add such measures to the protected areas’ missions.

Benefits of protecting whales

Protecting whales from ships would benefit other species too. Vessels can strike many marine species, including seals, sea turtles, sharks, fish, penguins and dolphins.

Marine shipping is the top source of underwater noise, which is a major threat to marine life. Underwater noise can disrupt feeding, interfere with communication and cause stress for many species. Vessels run more quietly at slower speeds, so speed-reduction measures can reduce noise pollution as well as collision risk.

Humans can also benefit from slowing down and rerouting ships. When vessels travel more slowly, their fuel efficiency increases, reducing their greenhouse gas emissions. The marine shipping industry currently produces carbon emissions comparable to those from aviation.

Slowing vessels down also reduces emissions of harmful air pollutants that threaten human health in coastal areas and are estimated to contribute to hundreds of thousands of premature deaths annually. In 2023, for example, vessels cooperating with a voluntary slowdown in California cut 45,000 metric tons of greenhouse gas emissions and 1,250 metric tons of nitrogen oxides, and they reduced the risk to whales by more than half.

Changing vessel routes can make waters safer for local fishermen. In Sri Lanka, for example, heavy ship traffic hugs the coast, overlapping with local fishermen as well as with foraging blue whales. Collisions with cargo ships have killed several fishermen there in recent years. In response, some shipping companies are voluntarily shifting their lanes farther offshore to reduce the risk of colliding with humans and whales.

In our interconnected world, 90% of consumer goods travel by ship before they get to market. Most items that consumers in wealthy nations purchase in their daily lives have traveled across the ocean at some point.

Our study shows that ship-strike risk is widespread – but in our view, protecting whales from these collisions is a solvable issue. And by protecting whales, humans can also protect themselves.

This article has been updated to add a video showing areas of the ocean that are used by whales, mapped in combination with global ship traffic.

Anna Nisi, Postdoctoral Researcher in Biology, University of Washington

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