Archives par mot-clé : Australia

The Great Barrier Reef could Die This Year?

by E. Worrall, Feb18, 2024 in WUWT


 

The Great Barrier Reef is in no danger of dying, at most it will change location a little. The reef is composed of an organism which has survived for at least 200 million years, through unimaginably catastrophic global extinction events and disasters, including the asteroid which killed the dinosaurs.

The reason that coral is so good at surviving great upheavals is that while adult coral is immobile, coral spawn is immensely mobile.

Every so often corals spawn. Corals produce immense clouds of microscopic eggs and sperms, which germinate into highly mobile microscopic coral larvae which seek out new places to colonise.

The Great Barrier Reef itself has moved location countless times over the millennia, the reef has only been at its current location for a few thousand years. Some Australian shorelines are composed of coral which lived thousands of years ago, during the Holocene Optimum, when the sea level was significantly higher than today. The Great Barrier Reef had and has no trouble changing location when climate change impacts sea conditions, such as when the world cooled after the end of the Holocene Optimum, and the sea waters retreated to today’s level.

And in fact, Australian coral coverage hit a record high a record high in 2022 – as an organism which is responsive to conditions, coral cover fluctuates wildly when conditions change.

Australia-wide assessment: climate change or instrument change?

by J. Marohasy, April 2023 in WUWT


In the five years following the installation of probes in automatic weather stations (AWS) as they replaced mercury thermometers across Australia, the annual frequency of extremely hot days increased by an average 18.7%.

This new analysis by Perth journalist and climate researcher Chris Gillham makes a mockery of claims by the Bureau that the transition from mercury thermometers to automatic weather stations has had no effect on temperatures, and so there is no need to transcribe or make public the parallel data.

Chris has found that a majority of these AWS stations had an average 62.8% increase in their 99th percentile observations. These are the hottest 1 per cent of days calculated since the start year of each station.

World’s Coral Reefs Not Declining, New Paper Reveals

by Dr. B. Peiser, Feb 8, 2023 in ClimateChangeDispatch


A new paperpublished by the Global Warming Policy Foundation refutes alarmist claims about the state of the world’s coral reefs.

According to the author, eminent reef scientist Peter Ridd, the official data show no signs of any long-term trends in reef health. [emphasis, links added]

Indeed, the best records – for Australia’s Great Barrier Reef – suggest that coral cover is at record highs.

Dr. Ridd said:

“The public is constantly told that reefs are being irreparably damaged by global warming, but bleaching events, about which there is so much doom-mongering, are simply corals’ natural response to changes in the environment. They are an extraordinarily adaptable lifeform, and bleaching events are almost always followed by rapid recovery.

Dr. Ridd suggests that rather than being seen as under threat from climate change, corals should actually be recognized as one of the organisms least likely to suffer harm in a warming world.

“Corals get energy from a symbiotic relationship with various species of algae. When environmental conditions change, they [coral] can rapidly switch to a different species that is better suited to the new conditions. This shapeshifting means that most setbacks they suffer will be short-lived.”

Dr. Ridd says that the real risks to reefs come from overfishingand pollution.

The GWPF invited responses to this paper from authors likely to dissent from its conclusions. None of the authors who were contacted accepted this invitation.

Peter Ridd: Coral in a Warming World: Causes for Optimism (pdf)

Natural Oceanic Cycles Behind Heavy East Australia Rains, New Study Finds

by P. Gosselin, Sep 21, 2022 in WUWT/NTZ


East Australia got hit by lots of rain in February earlier this year, and the media of course blamed it all on manmade climate change.

Now a new study by Holgate et al (2022) titled “The Impact of Interacting Climate Modes on East Australian Precipitation Moisture Sources” shows East Australia’s rains are directly tied to natural oceanic patterns.

Hat-tip: EIKE.

The paper’s abstract summarizes that east Australia precipitation is driven by multiple interacting climate modes and that the El Niño–Southern Oscillation (ENSO) modifies the supply of evaporative moisture for precipitation and that this is modulated by the Indian Ocean dipole (IOD) and southern annular mode (SAM).

Sources of moisture in eastern Australia. Source: Holgate et al, 2020

The Great Barrier Reef Is Doing Great; People Should Know

by P. Ridd, Aug 11, 2022 in CO2Coalition


Australia’s Great Barrier Reef (GBR) is, well, great. But the popular media won’t report this good news, so I will.

The GBR is made up of approximately 3,000 reefs covering an area nearly the size of California off Australia’s eastern coast. The condition of its coral is frequently referenced as an indicator of the reef’s health, regularly in the context of the supposed damage global warming is doing to the planet.

The reef now has more coral than any time since records began in 1986, according to  the Australian Institute of Marine Science (AIMS). There is roughly 20 percent more coral on the GBR than last year, which itself equaled a previous record year. All three major regions of the reef now have excellent coral cover and AIMS states that two regions are at record breaking high levels.

As of the latest 2022 survey of the GBR, coral covered 34 percent of the seabed, double the lowest coverage recorded in 2012. There are many types of ecosystem on reefs other than coral – 34% is a remarkably high number.

This coral health exists despite four supposedly massively destructive and unprecedented bleaching events striking parts of the reef since 2016 – all allegedly due to climate change and one as recently as this year. Coral reefs typically take five to 10 years to recover from major damage, so how can GBR be enjoying such good health this soon? Is it possible that reef-science institutions exaggerated the damage in the first place to advance the global warming narrative? Perhaps.

Sorry, CNN, Great Barrier Reef Is Setting Records, Fearmongering Won’t Work

by H.S. Burnett, Aug 7, 2022 in WUWT


A new report from the Australian Institute of Marine Science (AIMS) shows the Great Barrier Reef (GBR) set new records for extent this year. Sadly, in a story titled, “Parts of Great Barrier Reef record highest amount of coral in 36 years,” CNN tried to turn this good news contained in the headline into a climate cautionary tale.

According to AIMS’ annual report the northern and central regions of the 2,300 km GBR ecosystem have the most coral since the surveys began 36 years ago. As CNN notes, AIMS survey of 87 sections of the GBR found that between August 2021 and May 2022, average hard coral cover in the upper region and central areas of the reef increased by around one third. AIMS CEO Dr. Paul Hardisty told CNN that the report shows the GBR can “recover from mass bleaching and outbreaks of crown-of-thorns starfish that feed on coral.”

One could be forgiven for missing this good news since CNN spent just a few paragraphs discussing the GBR’s expansion. More than two thirds of CNN’s story talked about the threat posed to the GBR from recent bleaching events purportedly driven by climate change. CNN’s story largely ignored the fact that most of the GBR’s coral colonies impacted by bleaching had recovered, as the AIMS’ report documents.

In a press release from the Global Warming Policy Foundation (GWPF) commenting on the AIMS report its director, Benny Peiser, Ph.D., said, “This is just the latest example of empirical data making a mockery of the catastrophists. For how much longer do they think they can get away with it?”

“In recent years, the media around the world has been reporting coral bleaching events in increasingly apocalyptic terms,” Ridd said in the GWPF’s press release. “This data proves that they are simply scaremongering.”

AIMS’ annual survey confirms what previous posts on Climate Realism have shown, corals in the GBR and around the world are more adaptable than climate alarmists claim.

The evidence suggests, contrary to CNN’s fearmongering, climate change does not threaten to decimate the GBR or other coral reefs around the world. That’s something people around the globe can be thankful for.

The GWPF recently released a study discussing the positive health of coral reefs in general, by Peter Ridd, Ph.D., a long-time researcher on the GBR and coral reefs.

CNN Pushes Coral Apocalypse As Great Barrier Reef Shows Record Growth

by H.S. Sterling, Aug 5, 2022 in ClimateChangeDispatch


A new report from the Australian Institute of Marine Science (AIMS) shows the Great Barrier Reef (GBR) set new records for extent this year.

Sadly, in a story titled “Parts of Great Barrier Reef record highest amount of coral in 36 years,” CNN tried to turn this good news contained in the headline into a climate cautionary tale. [bold, links added]

According to the AIMS annual report, the northern and central regions of the 2,300 km GBR ecosystem have the most coral since the surveys began 36 years ago.

As CNN notes, an AIMS survey of 87 sections of the GBR found that between August 2021 and May 2022, average hard coral cover in the upper region and central areas of the reef increased by around one-third.

AIMS CEO Dr. Paul Hardisty told CNN that the report shows the GBR can “recover from mass bleaching and outbreaks of crown-of-thorns starfish that feed on coral.”

One could be forgiven for missing this good news since CNN spent just a few paragraphs discussing the GBR’s expansion.

More than two-thirds of CNN’s story talked about the threat posed to the GBR from recent bleaching events purportedly driven by climate change.

CNN’s story largely ignored the fact that most of the GBR’s coral colonies impacted by bleaching had recovered, as the AIMS report documents.

In a press release from the Global Warming Policy Foundation (GWPF) commenting on the AIMS report its director, Benny Peiser, Ph.D., said, “This is just the latest example of empirical data making a mockery of the catastrophists. For how much longer do they think they can get away with it?”

The GWPF recently released a study discussing the positive health of coral reefs in general, by Peter Ridd, Ph.D., a long-time researcher on the GBR and coral reefs.

..;

The Great Barrier Reef Is Strong, So Stop The Scare Campaign

by  P.  Ridd, Aug 5, 2022 in ClimateChangeDispatch


The latest data on the coral cover on the Great Barrier Reef, produced by the Australian Institute of Marine Science, should be a cause for celebration.

Church bells should be ringing and children given a day off from school. AIMS says two of the three main regions of the reef are at record-breaking high levels. [bold, links added]

The other region is at record-equaling levels (once uncertainty margins are taken into account).

AIMS, which has been releasing data on the reef every year since 1985, does not give the aggregate of coral cover for the entire reef; it stopped doing that in 2017.

So I have done it for AIMS, and the reef as a whole is at record high levels.

This result is proof that many scientific institutions have been misleading the public about the state of the reef.

They claimed we had four devastating and unprecedented bleaching events since 2016.

So much bleaching, death, and destruction has supposedly never happened before and is because of climate change – and now we have a record-high coral cover.

Official data confirms reef in rude good heath

by P. Homewood, Aug 4 , 2022 in NotaLotofPeopleKnowThat


Official data released today reveals that Australia’s Great Barrier Reef is in excellent health, with coral cover reaching record levels for the second consecutive year.

The increase will be surprising to members of the public, who are regularly hit with scare stories about coral bleaching and false tales about a reef in long-term decline.

A new note, published today by the Global Warming Policy Foundation, explains that the data shows clearly how a handful of coral bleaching events that have affected the reef since 2016 have had very limited impact on overall coral cover.

British colonisation of Australia 250 years ago to blame for recent wildfires

by P. Homewood, Feb 18, 2022 in NotaLotofPeopleKnowThat


Britain’s colonisation of Australia in the late 18th century is partly to blame for the nation’s recent ravaging by bushfires, a new study claims.

Before British ships carrying convicted criminals landed in New South Wales in January 1788, aboriginal people tended the landscape and were in charge of bushfire prevention.

But after the penal colony was established, and indigenous people were forced off their land and away from territories they had tended for centuries, the settlers took a new approach.

Suppression is now the primary focus. Instead of proactively and gradually reducing the risk of fire, authorities try to extinguish a fire as soon as possible after ignition.

Researchers from around the world, including Australia, have published a paper saying this change in tack has left Australia more vulnerable to wildfires now than it was 250 years ago.

“Indigenous people managed Australia’s flammable vegetation with “cultural burning” practices,” the study authors write in an article for The Conversation.

“These involved frequent, low-intensity fires which led to a fine-grained vegetation mosaic comprising grassy areas and scattered trees.

“Landscapes managed in this way were less prone to destructive fires. But under colonial rule, Aboriginal people were dispossessed of their lands and often prevented from carrying out many important practices.”

The change in wildfire prevention due to colonisation has left Australia more vulnerable to wildfires now than it was 250 years ago

….

 

Aussie Met Bureau – making up 13 years of missing temperature data

by D. Mason-Jones, Oct 15, 2021 in WUWT


Upon finding a 13-year gap in its data for an important weather station in Queensland, the Australian Bureau of Meteorology homogenised data from 10 other locations to fill-in the missing years. One of these places was more than 400km away and another almost 2.5 degrees of latitude further South.

Is the resulting data credible? No, is the conclusion reached in a research Report by Australian scientist, Dr. Bill Johnston.

When the US Army Air Force (USAAF) closed its heavy bomber transit base at Charleville at the end of the Second World War the aerodrome reverted to civilian status. The base had been a link in the ferry route delivering aircraft from factories in the US to the war zone.

 

Record Coral Cover Of Great Barrier Reef Shames Climate Alarmists, Media

by P. Ridd, July 23, 2021 in WUWT


The annual data on coral cover for the Great Barrier Reef, produced by the Australian Institute of Marine Science, was released on Monday showing the amount of coral on the reef is at record high levels.

Record high, despite all the doom stories by our reef science and management institutions.

Like all other data on the reef, this shows it is in robust health. For example, coral growth rates have, if anything, increased over the past 100 years, and measurements of farm pesticides reaching the reef show levels so low that they cannot be detected with the most ultra-sensitive equipment.

This data is good news. It could hardly be better. But somehow, our science organizations have convinced the world that the reef is on its last legs. How has this happened?

Measuring Old Corals & Coral Reefs (Part 1)

by J. Marohasy, Nov 29, 2020 in WUWT


Fundamental to science is measurement. It is a way of objectively assessing something, anything, even the state of a coral reef, even of an individual coral. Historically coral growth rates were measured by coring the really old massive Porites.

Like tree rings in temperate forests, the massive old Porites can be cored to see the banding and from this it is possible to calculate coral calcification rates which are a measure of the growth rate of individual corals.

Peter Ridd has been asking for some quality assurance of so many of the measurements relating to Great Barrier Reef health, including coral growth rates. Key Australian institutions have responded by stonewalling, and in the case of James Cook University, actually sacking him. After two rounds in the federal courts his appeal against his dismissal is finally going to the High Court of Australia, with the next hearing probably in February 2021. While the lawyers are preoccupied with Peter’s rights, or otherwise, to academic freedom and freedom of speech, my concern is whether Peter is actually telling the truth when he says that the Great Barrier Reef is resilient and definitely not dying from coral bleaching, though there is a problem with the integrity of the science.

 

Half the Reef destroyed but they won’t release the data

by JoNova, Oct 16, 2020


The future of the entire 350,000 km2 Great Barrier Reef hangs in the balance — as the coralapocalypse has wiped out 50% of the coral in just 25 years. Lordy! If only we’d built some off-shore wind farms on the reef to protect it! We could cover whole islands with solar panels? What are we thinking!

But as Peter Ridd points out, AIMS (The Australian Institute of Marine Science) surveys around 100 reefs every year — and for the last 35 years — and they find things are roughly the same. See the graph below.

Somehow Terry Hughes — and the Centre of Excellence for Integrated Coral Reef Studies — gets up to $4 million each year to report on the reef but won’t release the data behind the mass media campaign.

The ABC — which gets nearly $3 million dollars every single day — can’t even pick up the phone to interview AIMS or Peter Ridd and ask one hard question of Terry Hughes’ “Excellent” centre. (We all know why they had to put the word “excellence” in the title, it was the only way the word would ever be used to describe an activist group pretending to be scientists.)

And we all know that if anyone at James Cook University (JCU) has any doubts about the quality of the output from the “Excellent” centre they won’t be saying a word or they’ll get sacked like Peter Ridd did.

JCU — still supporting junk science and ignoring that other case of potential fraud?

Magically correcting Australia’s thermometers from 1,500 kilometers away

by JoNova, Oct 8, 2020


The Australian Bureau of Meteorology uses “surrounding” thermometers to adjust for odd shifts in data (caused by things like long grass, cracked screens, or new equipment, some of which is not listed in the site information). The Bureau fishes among many possible sites to find those that happen to match up or , err “correlate” during a particular five year period. Sometimes these are not the nearest site, but ones… further away. So the BOM will ignore the nearby stations, and use further ones to adjust the record.

These correlations, like quantum entanglements, are mysterious and fleeting. A station can be used once in the last hundred years to “correct” another, but for all the other years it doesn’t correlate well — which begs the question of why it had these special telediagnostic powers for a short while, but somehow lost them? Or why a thermometer 300km away might show more accurate trends than one 50km away.

One of the most extreme examples was when Cobar in NSW was used to adjust the records at Alice Springs –almost 1500km away (h/t Bill Johnston). That adjustment was 0.6°C down in 1932 (due to a site move, we’re told). This potentially matters to larger trends because Alice Springs is a long running remote station — the BOM itself says that Alice Springs alone contributes about 7-10 % of the national climate signal.[1] Curiously Cobar itself was adjusted in 1923 by a suite of ten stations including Bendigo Prison which is another 560 km farther south in a climate zone pretty close to Melbourne. In 1923 Cobar official temperatures were adjusted down by a significant 1.3 °C. No reason is given for this large shift — a shift larger than the entire (supposed) effect of CO2 in the last hundred years.

No Fuel, No Fire

by Mike Jonas, August 25, 2020 in WUWT


With wildfires devastating California, it may be worth while seeing if lessons can be learned from Australia. Connections between American and Australian firefighters go back many years, with each helping the other from time to time. There were devastating bushfires in Australia last summer, and, tragically, three Americans who had come to help were killed when their water tanker plane crashed. It’s now Australia’s turn to help California, and let us all hope there is a better outcome.

Gum trees burnt in the bushfires in The Blue Mountains in Australia

Submissions to Enquiries

Australia’s federal enquiry into the bushfires is not due to report until 28 October 2020 but the NSW [New South Wales] state enquiry report was published today. There were nearly 2,000 public submissions. Before I go into the report’s recommendations, it may be worth looking at a couple of the public submissions in order to understand the extreme level of public frustration with green tape and the way that the fire hazard has been allowed to grow ever larger over the years.

AUSTRALIA RECORDS ITS MOST SNOWFALL EVER OUTSIDE OF AN ALPINE AREA

by Cap Allon, August 25, 2020 in Electroverse


Antarctic air reaching Australia’s south east triggered snowfall down to low-lying regions across several states over the weekend and into Monday, with many people temporarily escaping house-arrest to enjoy the “once-in-a-15-year” event.

Heavy snow made for treacherous driving conditions near Old Adaminaby [Aug 23, 2020].

 

The town of Oberon received a record-breaking 20 cm (8 inches) of global warming goodness, the highest 24-hour snow total ever recorded outside of an Aussie alpine region. Traffic, predictably, was soon bumper-to-bumper through Hampton as tourists descended on Oberon to enjoy the snow–much to the chagrin of the local sheep. One Oberon resident reportedly bleated: “Let’s all go mingle with people from hot spots then risk taking something home. It will be so worth it.” And another jumbuck added: “I wonder what part of STAY AT HOME do all those idiots not understand.”

[VIDEO] NEW SOUTH WALES KANGAROOS GO TOE-TO-TOE IN THE SNOW DURING RECORD-BREAKING ANTARCTIC BLAST

by Cap Allon, August 12, 2020 in Electroverse


An Antarctic blast has brought record-breaking low temperatures and blizzard conditions across much of Australia this August, according to the Bureau of Meteorology — and even the kangas appear to have had their fill of it.

he heavy snowfall in New South Wales over recent days led to one lucky local capturing a pair of kangaroos going toe-to-toe in the driving snow:

see video

Reefs’ Neon Colors A Defense Against Coral Bleaching

by B. Bruno,  May 22, 2020 in ClimateChangeDispatch


Some coral reefs are adapting to warming ocean temperatures by making their own sunscreen in the form of bright neon colors — a strategy that invites coral animals to return to reefs and is seen as a critical adaptation to maintain healthy coral reefs around the world.

In a study published Thursday in the journal Current Biology, researchers at the University of Southampton detail a series of controlled laboratory experiments they conducted at their coral aquarium facility.

In the experiments, “colorful” coral bleaching events cause coral to produce a layer of vibrant sunscreen which encourages the coral animals vital to a mutually beneficial “symbiosis” relationship to return to coral habitats they abandon due to the effects of warming oceans.

The colorful adaptation could prove vital for overcoming the fatal coral bleaching incidents that have threatened coral reefs worldwide.

But the colorful coral bleaching – rather than the white skeleton exposure of common coral bleaching events – is believed to take place due to mild ocean warming or disturbances in their nutrient environment, rather than extreme events.

Colorful bleaching occurred between this past March and April in some areas of the Great Barrier Reef, suggesting some patches of the world’s largest reef system may have better recovery prospects than others.

Giant tectonic plate under Indian Ocean is breaking in two

by Geggel L., May 21, 2020 in LiveScience


The giant tectonic plate under the Indian Ocean is going through a rocky breakup … with itself.

In a short time (geologically speaking) this plate will split in two, a new study finds.

To humans, however, this breakup will take an eternity. The plate, known as the India-Australia-Capricorn tectonic plate, is splitting at a snail’s pace — about 0.06 inches (1.7 millimeters) a year. Put another way, in 1 million years, the plate’s two pieces will be about 1 mile (1.7 kilometers) farther apart than they are now.

“It’s not a structure that is moving fast, but it’s still significant compared to other planet boundaries,” said study co-researcher Aurélie Coudurier-Curveur, a senior research fellow of marine geosciences at the Institute of Earth Physics of Paris.

Related: In photos: Ocean hidden beneath Earth’s surface

For instance, the Dead Sea Fault in the Middle East is moving at about double that rate, or 0.2 inches (0.4 centimeters) a year, while the San Andreas Fault in California is moving about 10 times faster, at about 0.7 inches (1.8 cm) a year.

The plate is splitting so slowly and it’s so far underwater, researchers almost missed what they’re calling the “nascent plate boundary.” But two enormous clues — that is, two strong earthquakes originating in a strange spot in the Indian Ocean — suggested that Earth-changing forces were afoot.

On April 11, 2012, a magnitude-8.6 and magnitude-8.2 earthquake hit beneath the Indian Ocean, near Indonesia. The earthquakes didn’t happen along a subduction zone, where one tectonic plate slides under another. Instead, these quakes originated in a weird place for earthquakes to happen — in the middle of the plate.

POLAR COLD TO GRIP ALL OF AUSTRALIA: FORECASTS CALL FOR COLDEST APRIL DAYS IN A QUARTER OF A CENTURY

by Cap Allon , April 27, 2020 in Electroverse


The mainstream media won’t give a toss, but the ENTIRE Aussie continent is set for an early, bone-chilling taste of winter as a meridional jet stream flow (brought on by historically low solar activity) kicks brutal Antarctic air anomalously far north.

On Thursday and Friday this week, the maximum temperature in Melbourne –for example– is forecast to plummet to the lowest recorded level in April since 1996 (solar minimum of cycle 22) — a chilly 13C (55.3F)

Don’t fall for bogus, warm-mongering political agendas — the COLD TIMES are returning in line with historically low solar activitycloud-nucleating Cosmic Rays, and a meridional jet stream flow.

Even NASA agrees, in part at least, with their forecast for this upcoming solar cycle (25) revealing it will be “the weakest of the past 200 years,” with the agency correlating previous solar shutdowns to prolonged periods of global cooling here.

Three Decades of Mangrove Forest Biomass Change in NSW, Australia

by Lamont et al. , 2020 in CO2Science


Time and again climate alarmists have used computer models to claim that rising CO2 and rising temperatures should be negatively impacting various ecosystems, including forests. Given that these two parameters have supposedly reached unprecedented heights in modern history, reason suggests that this hypothesis of ecosystem decline should be presently evident in observational data. But is it?

Thanks to the work of Lamont et al. (2020) this question can be answered — at least for a mangrove forest ecosystem in New South Wales, Australia.

What the five Australian researchers did in their study was to examine the biomass change of two mangrove forest sites over the period 1989-2018. The two sites included a tall gallery forest composed of Avicennia marina (i.e., Site 1) and an interior, higher elevation, stunted mixed community of A. marina and Aegiceras corniculatum (i.e., Site 2). Data originally gathered in a 1989 survey were compared with new data obtained by Lamont et al. in 2018 and thereafter analyzed for possible trends.

Results of the analysis are summarized in the figure below, showing large gains in both aboveground and below ground biomass between the two survey dates at both mangrove forest sites. Of particular note is “a greater than seven-fold increase in mean aboveground biomass” at Site 2, and “a six-fold and 12-fold increase [in total below-ground root mass] at Site 1 and Site 2, respectively.” Such large biomass increases, not surprisingly, were estimated by the authors to have contributed to large gains in carbon sequestration. In extrapolating such gains to the entire New South Wales region, they estimate mangrove forests have sequestered “at least about 1.8 Tg C” over the past 70 years.

The above findings represent incredible growth benefits reaped by mangrove forest ecosystems during a time of rising atmospheric CO2 and rising temperature, which findings are pretty much the opposite of the doom and gloom predictions offered by climate alarmists.

The Proximal Drivers of Large Fires: A Pyrogeographic Study

by Clarke H. et al., April 3, 2020 in FrontierInEarthScience


Variations in global patterns of burning and fire regimes are relatively well measured, however, the degree of influence of the complex suite of biophysical and human drivers of fire remains controversial and incompletely understood. Such an understanding is required in order to support current fire management and to predict the future trajectory of global fire patterns in response to changes in these determinants. In this study we explore and compare the effects of four fundamental controls on fire, namely the production of biomass, its drying, the influence of weather on the spread of fire and sources of ignition. Our study area is southern Australia, where fire is currently limited by either fuel production or fuel dryness. As in most fire-prone environments, the majority of annual burned area is due to a relatively small number of large fires. We train and test an Artificial Neural Network’s ability to predict spatial patterns in the probability of large fires (>1,250 ha) in forests and grasslands as a function of proxies of the four major controls on fire activity. Fuel load is represented by predicted forested biomass and remotely sensed grass biomass, drying is represented by fraction of the time monthly potential evapotranspiration exceeds precipitation, weather is represented by the frequency of severe fire weather conditions and ignitions are represented by the average annual density of reported ignitions. The response of fire to these drivers is often non-linear. Our results suggest that fuel management will have limited capacity to alter future fire occurrence unless it yields landscape-scale changes in fuel amount, and that shifts between, rather than within, vegetation community types may be more important. We also find that increased frequency of severe fire weather could increase the likelihood of large fires in forests but decrease it in grasslands. These results have the potential to support long-term strategic planning and risk assessment by fire management agencies.