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.
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.
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.
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.
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.
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.
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.
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).
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
Considerable public debate has ensued on the positives and negatives (aka benefits versus risks) of Artificial Intelligence [AI]. The capability of the new systems cannot be fully quantified at this time however there are simple tests to demonstrate how such systems can interpret commands provided to them by users. On even a very simple, superficial level, AI can produce dramatically different results for the same question or request by a user.
The test above is one such example. A well known AI programme was tasked by a user to create an avatar image to assist the user to interact with the AI programme. The request was very basic without any significant details as to what image should be developed other than one should be female and one should be male with a positive expression. The AI program produced sample 1 for the female image and sample 2 for the male image. Is there an bias inherent within the AI programme ? That is hard to prove however the two images created could not be more different. Sample 1 is a very humanistic female image with a pleasant interactive professional expression. Sample 2 is an abstract almost idiotic impression of a non gender entity yet the instructions for each sample, female and male were identical and made at the same time.
As the calendar year of 2024 draws to a close, the time for rest, recreation and reflection on the past year and consideration of the year ahead is a time-honoured pastime. 2024 was a difficult year and does provide a partial events map of what may eventuate in 2025. A few critical influences to consider are listed below -
International relations: the Russian (Putin-initiated) unilateral war on Ukraine continues into another year with the exacting and tragic toll of civilian life unabated. The outcome is unknown as there are, like most major military conflicts, many variables whether political, technological (military)or social that will impact the course of the conflict. The war is one which does draw in multiple parties and cannot be defined only as regional conflict. The election of Donald J Trump as US President may affect the continuation of the war or it may not.
The Middle East remains a hotbed of turmoil with the ongoing Israel-Palestinian (Hamas) conflict together with the action taken by Israel against Hezbollah in Lebanon being central. The wildcard change has been the fall of the Assad regime in Syria that has been replaced by a collection of groups that formed the opposition to his dictatorship. Syria at present is geographically divided into different zones under various groups. Whether a cohesive multi-religious state can emerge from this situation is pure guesswork but the odds are not in favour of this outcome. Yemen and the Houthi insurgency continues to add a smaller yet measurable level of Middle Eastern instability.
Politics: the returning US President, Donald J Trump takes office in January 2025. Given the experience of Trump politics in the first Trump presidency, a fairly chaotic four years is the likely result. In the UK, the election of a Labour Government in July 2024 under Sir Keir Starmer has surprisingly led to a series of scandals in the first few months thus removing any sense of even a honeymoon period for the new leadership. In Europe, the Right of the political spectrum have gained much stronger positions in Holland, Italy, France, Austria and Germany reflecting considerable dissatisfaction with centrist or moderate left wing governments. There is no sign of this trend reversing in the next 12 months. Elsewhere totalitarian regimes continue in Russia, China and North Korea.
Economies: Economic instability and volatility will continue in 2025 with even more fluctuations as the Trump US Presidency gets underway and continuing conflicts in Eastern Europe and the Middle East . The real risk of either increased inflationary pressures or conversely stagflation cannot be underestimated. The slow-down in China exacerbated by the real estate/property development bubble then decline has proven to be difficult to counter and China's government has chosen the less effective policies to deal with it.
Environment and Climate Change: irrespective of what government is in power or what conflicts are occuring, the climate will change due to the increase in termperature with carbon emissions continuing at a high level and the risk of the release of higher methane emissions in the Northern Hemisphere ever more likely. Ice sheets and glaciers continue to melt at a higher than projected rate and sea level rises are correspondingly continuing. The reality that the agreed limitation of temperature increase to 1.5C cannot be met has yet to be formally acknowledged although many climate scientists have published that conclusion. Any reduction in the efforts to reduce carbon emissions and/or not move to sustainable renewable energy generation would lead to a dismal outcome for the planet and the human race. Each and every year counts at this point in time.
2025 at this stage promises more of the same from this perspective. At a more positive level there are many more ongoing discoveries in science and health and hope for the future is not to be discounted.
Wherever you are living in the world, may 2025 be a healthy, happy and peaceful year.
In 2017, NASA discovered and later confirmed the first interstellar object to enter our Solar System.
It wasn’t aliens. But artist impressions of the object (called ‘Oumuamua, the Hawaiian word for “scout”) do resemble an alien spaceship out of a sci-fi novel. This strange depiction is because astronomers don’t quite know how to classify the interstellar visitor.
Its speed and path around the Sun don’t match a typical asteroid, but it also has no bright tail or nucleus (icy core) we normally associate with comets. However, 'Oumuamua has erratic motions that are consistent with gas escaping from its surface. This “dark comet” has had astronomers scratching their heads ever since.
Flash forward to today, and more of these mysterious objects have been discovered, with another ten announced just last week. While their nature and origins remain elusive, astronomers recently confirmed dark comets fall into two main categories: smaller objects that reside in our inner Solar System, and larger objects (100 metres or more) that remain beyond the orbit of Jupiter.
In fact, 3200 Phaethon – the parent body of the famous Geminid meteor shower – may be one of these objects.
How do dark comets differ from normal comets?
Comets, often described as the Solar System’s “dirty snowballs”, are icy bodies made of rock, dust and ices. These relics of the early Solar System are critical to unlocking key mysteries around our planet’s formation, the origins of Earth’s water, and even the ingredients for life.
Astronomers are able to study comets as they make their close approach to our Sun. Their brilliant tails form as sunlight vaporises their icy surfaces. But not all comets put on such a dazzling display.
The newly discovered dark comets challenge our typical understanding of these celestial wanderers.
Image of comet C/2023 A3 Tsuchinshan-ATLAS taken by astronauts aboard the International Space Station.NASA
Dark comets are more elusive than their bright siblings. They lack the glowing tails and instead resemble asteroids, appearing as a faint point of light against the vast darkness of space.
However, their orbits set them apart. Like bright comets, dark comets follow elongated, elliptical paths that bring them close to the Sun before sweeping back out to the farthest reaches of the Solar System.
They go beyond Pluto, some even making it out to the Oort Cloud, a vast bubble of tiny objects at the fringe of our Solar System. Their speed and paths are what allow astronomers to determine their origins.
A comparison of dark comets and bright comets set against the Milky Way. On the left, a small, rocky, dark comet represents their typical size of one metre to a few hundred metres wide. On the right is a larger, icy, bright comet with a glowing tail, whose size ranges from 750 metres to 20 kilometres wide. The stark difference in size explains why dark comets lack the bright, visible tails of their larger, more iconic counterparts.Composition: Dr Kirsten Banks; Background image: R. Wesson/ESO; Dark comet: Nicole Smith/University of Michigan, made with Midjourney; Bright comet: Linda Davison
But what makes these comets so dark? There are three main reasons: size, spin and composition or age.
Dark comets are often small, just a few metres to a few hundred metres wide. This leaves less surface area for material to escape and form into the beautiful tails we see on typical comets. They often spin quite rapidly and disperse escaping gas and dust in all directions, making them less visible.
Lastly, their composition and age may result in weaker or no gas loss, as the materials that go into the tails of bright comets are depleted over time.
These hidden travellers may be just as important for astronomical studies, and they may even be related to their bright counterparts. Now, the challenge is to find more dark comets.
How can we find dark comets?
How do we even find these mysterious dark comets in the first place? As they get closer to the Sun, we don’t see spectacular tails of debris.
Instead, we rely on the light they reflect from our Sun.
Several astronomical images are combined to capture the faint, fast moving object ‘Oumuamua in the centre. The white streaks are stars.ESO/K. Meech et al.
These little guys might be stealthy for our eyes, but they are often no match for our large telescopes around the world. The discovery of ten new dark comets revealed last week was all thanks to one amazing instrument, the Dark Energy Camera (DECam) on a large telescope in Chile.
This camera can’t “see” dark energy directly, but it was designed to take massive photos of our universe – for us to see distant stars, galaxies and even hidden Solar System objects.
In their recent study, astronomers pieced together that some of these nightly images contained likely dark comets.
A) The Dark Energy Camera (DECam), mounted on the Victor M. Blanco four-metre telescope at the Cerro Tololo Inter-American Observatory in the Chilean Andes (Credit: Dark Energy Survey). B) Two examples of newly discovered dark comets within the DECam data, from Seligman et al. (2024).
The good news is, we are starting to focus more attention on these objects and on how to find them.
In even better news, in 2025, we’ll have a brand new mega camera in Chile ready to find them. This will be the Vera C. Rubin Observatory, with the largest digital camera ever built.
It will allow us to take more images of our night sky more quickly, and see objects that are even fainter. It’s likely that in the next ten years we could double or even triple the amount of known dark comets, and start to understand their interesting origin stories.
There could be more 'Oumuamua-like objects out there, just waiting for us to find them.
Christmas each year is a time of celebration, mixing with family and friends, observing religious rituals notably prayer / carol singing and exchanging gifts. Usually there is a message of sharing goodwill and generosity to those around us. Often it is also a time of considerable stress and isolation for others where families are in difficult domestic circumstances or there is separation by time and distance between family members. For the very old, whom may have outlived their peers and partners it can be especially difficult.
The origins of the Christmas celebration are considerably more humble than the current focus of materialistic consumerism. Until the 20th Century it was a more modest time with the emphasis on the spiritual experience.
The modern Christmas tree with decorations originates from Central Europe, predominantly Germany and the countries now known as Latvia and Estonia with records suggesting it became a common practice in the 16th Century. The Renaissance period in Europe is the most likely point in time when it commenced and gained wider use within the Lutheran Church and the Holy Roman Empire. The tree was decorated with representations of roses made from coloured paper, apples, wafers and sweet meats with a later addition being some candles. In its current form, the Christmas tree with electrification is effectively an extravagent light show in contrast.
With the earlier version of simplicity in mind, wherever you may be, Merry Christmas.
