AI and the myths of safety

Nobody wants to talk about AI safety. Instead they cling to 5 comforting myths

Google Deepmind / Unsplash

Paul Salmon, University of the Sunshine Coast

This week, France hosted an AI Action Summit in Paris to discuss burning questions around artificial intelligence (AI), such as how people can trust AI technologies and how the world can govern them.

Sixty countries, including France, China, India, Japan, Australia and Canada, signed a declaration for “inclusive and sustainable” AI. The United Kingdom and United States notably refused to sign, with the UK saying the statement failed to address global governance and national security adequately, and US Vice President JD Vance criticising Europe’s “excessive regulation” of AI.

Critics say the summit sidelined safety concerns in favour of discussing commercial opportunities.

Last week, I attended the inaugural AI safety conference held by the International Association for Safe & Ethical AI, also in Paris, where I heard talks by AI luminaries Geoffrey Hinton, Yoshua Bengio, Anca Dragan, Margaret Mitchell, Max Tegmark, Kate Crawford, Joseph Stiglitz and Stuart Russell.

As I listened, I realised the disregard for AI safety concerns among governments and the public rests on a handful of comforting myths about AI that are no longer true – if they ever were.

1: Artificial general intelligence isn’t just science fiction

The most severe concerns about AI – that it could pose a threat to human existence – typically involve so-called artificial general intelligence (AGI). In theory, AGI will be far more advanced than current systems.

AGI systems will be able to learn, evolve and modify their own capabilities. They will be able to undertake tasks beyond those for which they were originally designed, and eventually surpass human intelligence.

AGI does not exist yet, and it is not certain it will ever be developed. Critics often dismiss AGI as something that belongs only in science fiction movies. As a result, the most critical risks are not taken seriously by some and are seen as fanciful by others.

However, many experts believe we are close to achieving AGI. Developers have suggested that, for the first time, they know what technical tasks are required to achieve the goal.

AGI will not stay solely in sci-fi forever. It will eventually be with us, and likely sooner than we think.

2: We already need to worry about current AI technologies

Given the most severe risks are often discussed in relation to AGI, there is often a misplaced belief we do not need to worry too much about the risks associated with contemporary “narrow” AI.

However, current AI technologies are already causing significant harm to humans and society. This includes through obvious mechanisms such as fatal road and aviation crashes, warfare, cyber incidents, and even encouraging suicide.

AI systems have also caused harm in more oblique ways, such as election interference, the replacement of human work, biased decision-making, deepfakes, and disinformation and misinformation.

According to MIT’s AI Incident Tracker, the harms caused by current AI technologies are on the rise. There is a critical need to manage current AI technologies as well as those that might appear in future.

3: Contemporary AI technologies are ‘smarter’ than we think

A third myth is that current AI technologies are not actually that clever and hence are easy to control. This myth is most often seen when discussing the large language models (LLMs) behind chatbots such as ChatGPT, Claude and Gemini.

There is plenty of debate about exactly how to define intelligence and whether AI technologies truly are intelligent, but for practical purposes these are distracting side issues. It is enough that AI systems behave in unexpected ways and create unforeseen risks.

Several AI chatbots appear to display surprising behaviours, such as attempts at ‘scheming’ to ensure their own preservation. Apollo Research

For example, existing AI technologies have been found to engage in behaviours that most people would not expect from non-intelligent entities. These include deceit, collusion, hacking, and even acting to ensure their own preservation.

Whether these behaviours are evidence of intelligence is a moot point. The behaviours may cause harm to humans either way.

What matters is that we have the controls in place to prevent harmful behaviour. The idea that “AI is dumb” isn’t helping anyone.

4: Regulation alone is not enough

Many people concerned about AI safety have advocated for AI safety regulations.

Last year the European Union’s AI Act, representing the world’s first AI law, was widely praised. It built on already established AI safety principles to provide guidance around AI safety and risk.

While regulation is crucial, it is not all that’s required to ensure AI is safe and beneficial. Regulation is only part of a complex network of controls required to keep AI safe.

These controls will also include codes of practice, standards, research, education and training, performance measurement and evaluation, procedures, security and privacy controls, incident reporting and learning systems, and more. The EU AI act is a step in the right direction, but a huge amount of work is still required to develop the appropriate mechanisms required to ensure it works.

5: It’s not just about the AI

The fifth and perhaps most entrenched myth centres around the idea that AI technologies themselves create risk.

AI technologies form one component of a broader “sociotechnical” system. There are many other essential components: humans, other technologies, data, artefacts, organisations, procedures and so on.

Safety depends on the behaviour of all these components and their interactions. This “systems thinking” philosophy demands a different approach to AI safety.

Instead of controlling the behaviour of individual components of the system, we need to manage interactions and emergent properties.

With AI agents on the rise – AI systems with more autonomy and the ability to carry out more tasks – the interactions between different AI technologies will become increasingly important.

At present, there has been little work examining these interactions and the risks that could arise in the broader sociotechnical system in which AI technologies are deployed. AI safety controls are required for all interactions within the system, not just the AI technologies themselves.

AI safety is arguably one of the most important challenges our societies face. To get anywhere in addressing it, we will need a shared understanding of what the risks really are.

Paul Salmon, Professor of Human Factors, University of the Sunshine Coast

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

Climate change - entering a new phase ?

Earth is already shooting through the 1.5°C global warming limit, two major studies show

Andrew King, The University of Melbourne and Liam Cassidy, The University of Melbourne

Earth is crossing the threshold of 1.5°C of global warming, according to two major global studies which together suggest the planet’s climate has likely entered a frightening new phase.

Under the landmark 2015 Paris Agreement on climate change, humanity is seeking to reduce greenhouse gas emissions and keep planetary heating to no more than 1.5°C above the pre-industrial average. In 2024, temperatures on Earth surpassed that limit.

This was not enough to declare the Paris threshold had been crossed, because the temperature goals under the agreement are measured over several decades, rather than short excursions over the 1.5°C mark.

But the two papers just released use a different measure. Both examined historical climate data to determine whether very hot years in the recent past were a sign that a future, long-term warming threshold would be breached.

The answer, alarmingly, was yes. The researchers say the record-hot 2024 indicates Earth is passing the 1.5°C limit, beyond which scientists predict catastrophic harm to the natural systems that support life on Earth.

2024: the first year of many above 1.5°C

Climate organisations around the world agree last year was the hottest on record. The global average temperature in 2024 was about 1.6°C above the average temperatures in the late-19th century, before humans started burning fossil fuels at large scale.

Earth has also recently experienced individual days and months above the 1.5°C warming mark.

But the global temperature varies from one year to the next. For example, the 2024 temperature spike, while in large part due to climate change, was also driven by a natural El Niño pattern early in the year. That pattern has dissipated for now, and 2025 is forecast to be a little cooler.

These year-to-year fluctuations mean climate scientists don’t view a single year exceeding the 1.5°C mark as a failure to meet the Paris Agreement.

However, the new studies published today in Nature Climate Change suggest even a single month or year at 1.5°C global warming may signify Earth is entering a long-term breach of that vital threshold.

What the studies found

The studies were conducted independently by researchers in Europe and Canada. They tackled the same basic question: is a year above 1.5°C global warming a warning sign that we’re already crossing the Paris Agreement threshold?

Both studies used observations and climate model simulations to address this question, with slightly different approaches.

In the European paper, the researchers looked at historical warming trends. They found when Earth’s average temperature reached a certain threshold, the following 20-year period also reached that threshold.

This pattern suggests that, given Earth reached 1.5°C warming last year, we may have entered a 20-year warming period when average temperatures will also reach 1.5°C.

The Canadian paper involved month-to-month data. June last year was the 12th consecutive month of temperatures above the 1.5°C warming level. The researcher found 12 consecutive months above a climate threshold indicates the threshold will be reached over the long term.

Both studies also demonstrate that even if stringent emissions reduction begins now, Earth is still likely to be crossing the 1.5°C threshold.

Heading in the wrong direction

Given these findings, what humanity does next is crucial.

For decades, climate scientists have warned burning fossil fuels for energy releases carbon dioxide and other gases that are warming the planet.

But humanity’s greenhouse gas emissions have continued to increase. Since the Intergovernmental Panel on Climate Change released its first report in 1990, the world’s annual carbon dioxide emissions have risen about 50%.

Put simply, we are not even moving in the right direction, let alone at the required pace.

The science shows greenhouse gas emissions must reach net-zero to end global warming. Even then, some aspects of the climate will continue to change for many centuries, because some regional warming, especially in the oceans, is already locked in and irreversible.

If Earth has indeed already crossed the 1.5°C mark, and humanity wants to get below the threshold again, we will need to cool the planet by reaching “net-negative emissions” – removing more greenhouse gases from the atmosphere than we emit. This would be a highly challenging task.

Feeling the heat

The damaging effects of climate change are already being felt across the globe. The harm will be even worse for future generations.

Australia has already experienced 1.5°C of warming, on average, since 1910.

Our unique ecosystems, such as the Great Barrier Reef, are already suffering because of this warming. Our oceans are hotter and seas are rising, hammering our coastlines and threatening marine life.

Bushfires and extreme weather, especially heatwaves, are becoming more frequent and severe. This puts pressure on nature, society and our economy.

But amid the gloom, there are signs of progress.

Across the world, renewable electricity generation is growing. Fossil fuel use has dropped in many countries. Technological developments are slowing emissions growth in polluting industries such as aviation and construction.

But clearly, there is much more work to be done.

Humanity can turn the tide

These studies are a sobering reminder of how far short humanity is falling in tackling climate change.

They show we must urgently adapt to further global warming. Among the suite of changes needed, richer nations must support the poorer countries set to bear the most severe climate harms. While some progress has been made in this regard, far more is needed.

A major shift is also needed to decarbonise our societies and economies. There is still room for hope, but we must not delay action. Otherwise, humanity will keep warming the planet and causing further damage.

Andrew King, Associate Professor in Climate Science, ARC Centre of Excellence for 21st Century Weather, The University of Melbourne and Liam Cassidy, PhD Candidate, The University of Melbourne

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

Asteroid 2024/YR4 - a near earth miss but later possible collision ?

Astronomers have spied an asteroid that may be heading for Earth. Here’s what we know so far

Artist’s impression of an asteroid with Earth in the background. Buradaki / Shutterstock

Jonti Horner, University of Southern Queensland

On 27 December last year, astronomers using the ATLAS survey telescope in Chile discovered a small asteroid moving away from Earth. Follow up observations have revealed that the asteroid, 2024 YR4, is on a path that might lead to a collision with our planet on December 22 2032.

In other words, the newly-discovered space rock poses a significant impact threat to our planet.

It sounds like something from a bad Hollywood movie. But in reality, there’s no need to panic – this is just another day living on a target in a celestial shooting gallery.

So what’s the story? What do we know about 2024 YR4? And what would happen if it did collide with Earth?

A target in the celestial shooting gallery

As Earth moves around the Sun, it is continually encountering dust and debris that dates back to the birth of the Solar system. The system is littered with such debris, and the meteors and fireballs seen every night are evidence of just how polluted our local neighbourhood is.

But most of the debris is far too small to cause problems to life on Earth. There is far more tiny debris out there than larger chunks – so impacts from objects that could imperil life on Earth’s surface are much less frequent.

The most famous impact came some 66 million years ago. A giant rock from space, at least 10 kilometres in diameter, crashed into Earth – causing a mass extinction that wiped out something like 75% of all species on Earth.

Impacts that large are, fortunately, very rare events. Current estimates suggest that objects like the one which killed the dinosaurs only hit Earth every 50 million years or so. Smaller impacts, though, are more common.

On June 30 1908, there was a vast explosion in a sparsely populated part of Siberia. When explorers later reached the location of the explosion, they found an astonishing site: a forest levelled, with all the trees fallen in the same direction. As they moved around, the direction of the fallen trees changed – all pointing inwards towards the epicentre of the explosion.

The Tunguska event flattened trees over an area of around 2,200 square kilometres. Leonid Kulik / Wikimedia

In total, the Tunguska event levelled an area of almost 2,200 square kilometres – roughly equivalent to the area of greater Sydney. Fortunately, that forest was extremely remote. While plants and animals were killed in the blast zone, it is thought that, at most, only three people perished.

Estimates vary of how frequent such large collisions should be. Some argue that Earth should experience a similar impact, on average, once per century. Others suggest such collisions might only happen every 10,000 years or so. The truth is we don’t know – but that’s part of the fun of science.

More recently, a smaller impact created global excitement. On 15 February 2013, a small asteroid (likely about 18 metres in diameter) detonated near the Russian city of Chelyabinsk.

The explosion, about 30 kilometres above the Earth’s surface, generated a powerful shock-wave and extremely bright flash of light. Buildings were damaged, windows smashed, and almost 1,500 people were injured – although there were no fatalities.

It served as a reminder, however, that Earth will be hit again. It’s only a question of when.

Which brings us to our latest contender – asteroid 2024 YR4.

The 1-in-77 chance of collision to watch

2024 YR4 has been under close observation by astronomers for a little over a month. It was discovered just a few days after making a relatively close approach to our planet, and it is now receding into the dark depths of the Solar System. By April, it will be lost to even the world’s largest telescopes.

The observations carried out over the past month have allowed astronomers to extrapolate the asteroid’s motion forward over time, working out its orbit around the Sun. As a result, it has become clear that, on December 22 2032, it will pass very close to our planet – and may even collide with us.

The area at risk of a strike, based on current (highly uncertain) data. Daniel Bamberger / Wikimedia, CC BY-SA

At present, our best models of the asteroid’s motion have an uncertainty of around 100,000 kilometres in its position at the time it would be closest to Earth. At around 12,000 kilometres in diameter, our planet falls inside that region of uncertainty.

Calculations suggest there is currently around a 1-in-77 chance that the asteroid will crash into our planet at that time. Of course, that means there is still a 76-in-77 chance it will miss us.

When will we know for sure?

With every new observation of 2024 YR4, astronomers’ knowledge of its orbit improves slightly – which is why the collision likelihoods you might see quoted online keep changing. We’ll be able to follow the asteroid as it recedes from Earth for another couple of months, by which time we’ll have a better idea of exactly where it will be on that fateful day in December 2032.

But it is unlikely we’ll be able to say for sure whether we’re in the clear at that point.

Recent observations of 2024 YR4 – the faint unmoving dot in the centre of the image. ESO, CC BY

Fortunately, the asteroid will make another close approach to the Earth in December 2028 – passing around 8 million kilometres from our planet. Astronomers will be ready to perform a wide raft of observations that will help us to understand the size and shape of the asteroid, as well as giving an incredibly accurate overview of where it will be in 2032.

At the end of that encounter, we will know for sure whether there will be a collision in 2032. And if there is to be a collision that year, we’ll be able to predict where on Earth that collision will be – likely to a precision of a few tens of kilometres.

How big would the impact be?

At the moment, we don’t know the exact size of 2024 YR4. Even through Earth’s largest telescopes, it is just a single tiny speck in the sky. So we have to estimate its size based on its brightness. Depending on how reflective the asteroid is, current estimates place it as being somewhere between 40 and 100 metres across.

What does that mean for a potential impact? Well, it would depend on exactly what the asteroid is made of.

The most likely scenario is that the asteroid is a rocky pile of rubble. If that turns out to be the case, then the impact would be very similar to the Tunguska event in 1908.

The asteroid would detonate in the atmosphere, with a shockwave blasting Earth’s surface as a result. The Tunguska impact was a “city killer” type event, levelling forest across a city-sized patch of land.

Meteor Crater in Arizona is believed to have been created by a 50m metallic meteorite impact around 50,000 years ago. NASA Earth Observatory / Wikimedia

A less likely possibility is that the asteroid is made of metal. Based on its orbit around the Sun, this seems unlikely – but we can’t rule it out.

In that case, the asteroid would make it through the atmosphere intact, and crash into Earth’s surface. If it hit on the land, it would carve out a new impact crater, probably more than a kilometre across and a couple of hundred metres deep – something similar to Meteor Crater in Arizona.

Again, this would be quite spectacular for the region around the impact – but that would be about it.

Living in a remarkable time

This all sounds like doom and gloom. After all, we know that the Earth will be hit again – either by 2024 YR4 or something else. But there’s a real positive to take out of all this.

There has been life on Earth for more than 3 billion years. In all that time, impacts have come along and caused destruction and devastation many times.

But there has never been a species, to our knowledge, that understood the risk, could detect potential threats in advance, and even do something about the threat. Until now.

In just the past few years, we have discovered 11 asteroids before they hit our planet. In each case, we have predicted where they would hit, and watched the results.

We have also, in recent years, demonstrated a growing capacity to deflect potentially threatening asteroids. NASA’s DART mission (the Double Asteroid Redirection Test) was an astounding success.

For the first time in more than 3 billion years of life on Earth, we can do something about the risk posed by rocks from space. So don’t panic! But instead, sit back and watch the show.

Jonti Horner, Professor (Astrophysics), University of Southern Queensland

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

Avocadoes - the types

 What’s the difference between Hass and Shepard avocados? It’s not just the colour

Stepanenco Valeria/Unsplash

Yasmine Probst, University of Wollongong and Karen Zoszak, University of Wollongong

Whether with crumbled feta or poached eggs, you’d be challenged to find a cafe in Australia or farther afield that doesn’t have avocado somewhere on the menu.

This fruit (yep, it’s a fruit from a tree, not a vegetable) is widely associated with brunch culture and other trendy eating habits.

The Australian avocado industry developed in the 1960s, 30 years after the start of the first large-scale production in California. Orchards producing avocados now span most parts of Australia.

Avocados are considered a monoculture crop: they’re grown on the same land each year, making them more susceptible to pests and creating a need for increased fertiliser use. The carbon footprint of avos is almost twice as high as that of apples, but much lower than many animal food sources.

There are now over 50 different avocado types globally, but only a few are grown commercially.

Not all avos are the same

You may not notice a difference when you get your avocado toast at a cafe. But at the shops or the market, a striking difference occurs each year in Australia.

In autumn, the familiar dark purple Hass avocado disappears and is replaced with the lighter green Shepard variety. In Australia, this typically happens between February and May.

If you don’t know the difference between the two, you may expect Shepard avos to perform the same way as Hass – and be left disappointed. There are some important differences.

Hass avocados

Hass avocado skin is very dark when ripe. Nungning20/Shutterstock

Hass avocados are known for their dark, pebbly-looking skin that appears almost black when ripe. They have an ovoid shape with a slight pear-like appearance. The thick skin can be a challenge to peel, often requiring a sharp knife or avocado slicer.

Hass avocado flavour is rich, creamy and buttery, with nutty undertones. Their texture is ideal for mashing, blending and spreading, creating a creamy texture in dips, guacamole and smoothies.

Hass avocados ripen – and darken in colour – slowly over several days. They remain firm to the touch when ripe, and will feel squishy when overripe. A slight give when pressed confirms Hass avos are ready to eat.

Available in Australia from May to January, Hass are the dominant variety of commercially grown avocado worldwide. They were cultivated by horticulturalist Rudolph Hass in California in the 1920s.

Shepard avocados

Shepard avocados have smooth, green skin that remains green even when they are fully ripe. They are round to slightly oblong in shape and have a slightly milder and sweeter taste, with less pronounced nutty undertones.

Shepard avocados ripen more quickly than Hass, but you won’t be able to tell that by the colour. Instead, check for softness – Shepard avocados are very soft when ripe. What might feel overripe when handling a Hass will likely be ideal ripeness if it’s a Shepard. The thin, smooth skin makes them easy to peel by hand or with a gentle squeeze.

Their buttery soft texture is firm and creamy, and they hold their shape well when cut, making them ideal for slicing, dicing and spreading despite being structurally firm.

Interestingly, Shepard avocados brown much more slowly than Hass, making them perfect for garnishes. Their milder flavour also makes Shepard avos well suited to sweet dishes, such as chocolate mousse.

Shepard avos account for approximately 10–15% of Australian avocados and are in season from February to April each year while there is a gap in the Hass season.

Australia is the only country in the world that grows Shepard avocados commercially. (They are grown in Queensland.)

Avocados and our health

As avocados contain roughly 13 grams of fat per 100g, people wishing to lose weight were previously advised to avoid or limit eating them.

We now know that a majority of this fat is oleic acid, a monounsaturated (healthy) fat that helps to reduce cholesterol and improve heart health.

Additionally, only 1% of an avocado is made up of carbohydrates, making the fruit popular with people following a ketogenic (keto) diet of low carbs and high fat.

People who consume avos also tend to follow a better pattern of eating in general. They eat more whole grains, fruit and vegetables and fewer discretionary or takeaway foods.

As an energy-dense food, consuming a whole avocado is about the same as eating 2.5 whole apples. Per 100 grams, avocado actually gives you less energy than an equivalent amount of cooked white rice.

As avocado dishes are visually appealing and often featured in food photography, they have become a symbol of modern eating habits.

Correction: this article has been amended to clarify that most parts of Australia now have avocado orchards, and that avocados have roughly 13g of fat per 100g, not 53%.

Yasmine Probst, Professor, School of Medical, Indigenous and Health Sciences, University of Wollongong and Karen Zoszak, Accredited Practising Dietitian, PhD Candidate, University of Wollongong

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

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

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

The Copernicus Institute summarised the situation thus:  

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

Key points -

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

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

Los Angeles fires and the Santa Ana winds

 How Santa Ana winds fueled the deadly fires in Southern California

Over 1,000 structures burned in the span of two days, Jan 7-8, 2025, near Los Angeles. AP Photo/Ethan Swope

Jon Keeley, University of California, Los Angeles

Powerful Santa Ana winds, near hurricane strength at times, swept down the mountains outside Los Angeles and pushed wildfires into several neighborhoods starting Jan. 7, 2025. Well over 1,000 homes and several schools had burned by Jan. 8, and at least five people had died. Officials urged more than 100,000 residents to evacuate at the height of the fires, but with the winds so strong, there was little firefighters could do to control the flames.

Jon Keeley, a research ecologist in California with the U.S. Geological Survey and adjunct professor at UCLA, explains what causes extreme winds like this in Southern California, and why they create such a dangerous fire risk.

What causes the Santa Ana winds?

The Santa Ana winds are dry, powerful winds that blow down the mountains toward the Southern California coast.

The region sees about 10 Santa Ana wind events a year on average, typically occurring from fall into January. When conditions are dry, as they are right now, these winds can become a severe fire hazard.

Santa Ana winds blow down the mountains toward the coast, drying and warming as they descend. USGS

The Santa Ana winds occur when there is high pressure to the east, in the Great Basin, and a low-pressure system off the coast. Air masses move from high pressure to low pressure, and the more extreme the difference in the pressure, the faster the winds blow.

Topography also plays a role.

As the winds rush downslope from the top of the San Gabriel Mountains, they become drier and hotter. That’s a function of the physics of air masses. By the time the winds get to the point where the Eaton Fire broke out in Altadena on Jan. 7, it’s not uncommon for them to have less than 5% relative humidity, meaning essentially no moisture at all.

Canyons also channel the winds. I used to live in the Altadena area, and we would get days during Santa Ana wind events when the wind wasn’t present at all where we lived, but, a few blocks away, the wind was extremely strong.

These strong, dry winds are often around 30 to 40 mph. But they can be stronger. The winds in early January 2025 were reported to have reached 60 to 70 mph.

Why was the fire risk so high this time?

Typically, Southern California has enough rain by now that the vegetation is moist and doesn’t readily burn. A study a few years ago showed that autumn moisture reduces the risk of Santa Ana wind-driven fires.

This year, however, Southern California has very dry conditions, with very little moisture over the past several months. With these extreme winds, we have the perfect storm for severe fires.

Dark smoke from the fires was evident from the Santa Monica, Calif., pier on Jan. 8, 2025. AP Photo/Richard Vogel

It’s very hard to extinguish a fire under these conditions. The firefighters in the area will tell you, if there’s a Santa Ana wind-driven fire, they will evacuate people ahead of the fire front and control the edges – but when the wind is blowing like this, there’s very little chance of stopping it until the wind subsides.

Other states have seen similar fires driven by strong downslope winds. During the Chimney Tops 2 Fire in Tennessee in November 2016, strong downslope winds spread the flames into homes in Gatlinburg, killing 14 people and burning more than 2,500 homes. Boulder County, Colorado, lost about 1,000 homes when powerful winds coming down the mountains there spread the Marshall Fire in December 2021.

Have the Santa Ana winds changed over time?

Santa Ana wind events aren’t new, but we’re seeing them more often this time of year.

My colleagues and I recently published a paper comparing 71 years of Santa Ana wind events, starting in 1948. We found about the same amount of overall Santa Ana wind activity, but the timing is shifting from fewer events in September and more in December and January. Due to well-documented trends in climate change, it is tempting to ascribe this to global warming, but as yet there is no substantial evidence of this.

California is seeing more destructive fires than we saw in the past. That’s driven not just by changes in the climate and the winds, but also by population growth.

More people now live in and at the edges of wildland areas, and the power grid has expanded with them. That creates more opportunities for fires to start. In extreme weather, power lines face a higher risk of falling or being hit by tree branches and sparking a fire. The area burnt because of fires related to power lines has greatly expanded; today it is the major ignition source for destructive fires in Southern California.

Firefighters work to extinguish burning homes in the Pacific Palisades neighborhood of Los Angeles on Jan. 8, 2025. AP Photo/Damian Dovarganes

The Eaton Fire, which has burned many homes, is at the upper perimeter of the San Gabriel Basin, at the base of the San Gabriel Mountains. Fifty years ago, fewer people lived there. Back then, some parts of the basin were surrounded by citrus orchards, and fires in the mountains would burn out in the orchards before reaching homes.

Today, there is no buffer between homes and the wildland. The point of ignition for the Eaton Fire appears to have been near or within one of those neighborhoods.

Homes are made of dried materials, and when the atmosphere is dry, they combust readily, allowing fires to spread quickly through neighborhoods and creating a great risk of destructive fires.

Jon Keeley, Research Ecologist, USGS; Adjunct Professor, University of California, Los Angeles

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

Parasites - their role and value

Mind-bending, body-snatching, blood-sucking: parasites are bizarre yet vital for life on Earth

ijimino, Shutterstock

Euan Ritchie, Deakin University

Parasite, zombie, leech – these words are often used to describe people in unkind ways. Many of us recoil when ticks, tapeworms, fleas, head lice or bed bugs are even mentioned. Coming across such unwelcome guests – in our hair, on our skin or in our beds – can be a real nightmare.

Some parasites cause horrific deformities and diseases, maiming and killing millions of people and wildlife. Others may help boost immunity or provide the basis of food chains.

Parasites are often demonised and misunderstood. But the more we study these oddities and wonders of evolution, the more we appreciate their vital roles in ecosystems and our complex relationships with them. They’re essential to life on Earth.

As an ecologist with a focus on wildlife and conservation, I wrote this article to share some of my fascination for parasites and the importance of their extraordinary lives.

Cuckoos are known as brood parasites, tricking other birds into raising their own young.

What is a parasite?

Parasites rely on living organisms for food, to grow and to reproduce.

They can either live on the outside (ectoparasites) or inside (endoparasites) of their hosts. Far from being invited dinner guests, parasites typically turn up of their own accord and feed at the host’s expense, consuming part or all of them.

Parasites can live within their host (or hosts) for short or extended periods – in some cases many years – going largely unnoticed. For instance, one man lived with a tapeworm in his brain for more than four years until the headaches and strange smells become too much to bear. In other cases, parasites can kill their host.

Perhaps the most gruesome type of parasite, parasitoids, kill their hosts in order to reproduce. The disturbing chest-bursting scene from the 1979 movie Alien is a truly visceral sci-fi example of a parasitoid.

In real life, examples include spider wasps that first immobilise their spider prey, lay an egg on them, and bury them. Then when the egg hatches, the wasp larvae devour the incapacitated spider. That is, of course, if another animal such as a “bin chicken (Sacred Ibis)” or insect doesn’t intervene.

Parasites are widespread and profoundly affect our world.

Parasites are typically much smaller than their hosts. Many are furnished with equipment for latching on and remaining attached, including hooks, suckers and “teeth”.

Endoparasites such as tapeworms are often flat, allowing them to live within the tight spaces inside other organisms. The flatworm Diplozoon paradoxum that lives in gills of some fish must conjoin with another to reach adulthood and reproduce. Once fused, they form a permanent, lifelong bond and mate with each other over many years.

As much as 40% of all animal species may be parasites, and this mode of life might have evolved more than 200 times in the animal kingdom. But parasitism is not solely confined to animals. Many plants, fungi, protists, bacteria and viruses are parasites too.

Parasite powers

The leech scene in the iconic 1986 movie Stand By Me comes back to me every time I walk through a damp forest. The idea of providing a blood meal for another species sparks fear in many people. But leeches may also come to our aid, either by helping to reduce pooling of blood or reestablishing blood flow to areas post-surgery. Their anaesthetic saliva also has anti-inflammatory and anticoagulant properties, which are advantageous for medical procedures.

As the blood of leeches contains DNA from their past meals, conservation scientists can use them to search for rare and cryptic wildlife.

Leeches are aiding wildlife conservation.

One of the world’s most widespread parasites is Toxoplasma gondii. Some estimates suggest as many as one in three people are affected. This parasite’s main host is cats, large and small species. House cats are frequently infected, spreading this parasite through their faeces.

While many infected people appear to have no symptoms, serious effects can include organ damage, complications with pregnancy or abortion, erratic risk-taking behaviour, mental conditions, and more traffic accidents than unaffected people.

There are potential “benefits” too. Research suggests Toxoplasma infection, which can increase confidence and risk-taking, may even be linked with increased entrepreneurial and business-related activities. Indeed, this same study found that nations with higher rates of toxoplasmosis had a lower proportion of individuals concerned about failure related to new business ventures.

Toxoplasmosis is associated with a vast array of symptoms and medical conditions.

Toxoplasma gondii manipulates its host to increase transmission and continue its life cycle. Infected rodents may become unwitting participants in a game of cat-and-mouse-and-parasite in which they lose their fear of cats and instead become attracted to them.

Rather than manipulating host behaviour, as in the case of fungi that turn ants into zombies, some parasites cause body malformations. This makes hosts more likely to become prey for subsequent hosts and hence to continue the parasite’s life cycle. One of the most striking examples is a trematode (flatworms often known as flukes) that causes missing legs, extra legs or deformed legs in frogs and other amphibians. Extra legs, in some cases several, serve no function and simply impede movement, making it harder to escape predators.

Sometimes extra legs are a hindrance not helpful. Brett Goodman and Pieter Johnson

Parasites are fundamental to ecosystems and require conservation

Parasites are a big part of life on Earth. A study on the Californian coast found the sheer mass of parasites exceeded that of top predators. In particular, the biomass of trematodes was greater than that of birds, fish, burrowing shrimps and polychaetes (marine worms).

Evidence suggests ecosystems rich in parasites are healthier than those with fewer parasites. But there is increasing concern for the survival of these species amid a growing extinction crisis. So a global plan for parasite conservation was proposed in 2020, with priorities including increased data collection and genetic analysis, making conservation assessments, and raising public awareness.

Sadly, parasites can inflict great pain, meat allergies, suffering, and a heavy death toll. Malaria, schistosomiasis (sometimes referred to as snail fever, bilharzia, and Katayama fever), and sleeping sickness are just a few examples.

But they also shape our world in profound ways, have crucial ecological roles, and paradoxically, may in some cases help keep us healthier. Though it may be confronting to admit, we need parasites as much as they need us.

The presence of parasites (Gyrodactylus turnbulli) can affect how colourful male guppies are, influencing their ability to attract mates. Wikimedia commons, CC BY

Euan Ritchie, Professor in Wildlife Ecology and Conservation, School of Life & Environmental Sciences, Deakin University

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