Firestorms and flaming tornadoes: how bushfires create their own ferocious weather systems



A firestorm on Mirror Plateaun Yellowstone Park, 1988.
Jim Peaco/US National Park Service

Rachel Badlan, UNSW

As the east coast bushfire crisis unfolds, New South Wales Premier Gladys Berejiklian and Rural Fire Service operational officer Brett Taylor have each warned residents bushfires can create their own weather systems.

This is not just a figure of speech or a general warning about the unpredictability of intense fires. Bushfires genuinely can create their own weather systems: a phenomenon known variously as firestorms, pyroclouds or, in meteorology-speak, pyrocumulonimbus.




Read more:
Firestorms: the bushfire/thunderstorm hybrids we urgently need to understand


The occurrence of firestorms is increasing in Australia; there have been more than 50 in the period 2001-18. During a six-week period earlier this year, 18 confirmed pyrocumulonimbus formed, mainly over the Victorian High Country.

A pyrocumulonimbus cloud generated by a bushfire in Licola,Victoria, on March 2, 2019.
Elliot Leventhal, Author provided

Its not clear whether the current bushfires will spawn any firestorms. But with the frequency of extreme fires set to increase due to hotter and drier conditions, it’s worth taking a closer look at how firestorms happen, and what effects they produce.

What is a firestorm?

The term “firestorm” is a contraction of “fire thunderstorm”. In simple terms, they are thunderstorms generated by the heat from a bushfire.

In stark contrast to typical bushfires, which are relatively easy to predict and are driven by the prevailing wind, firestorms tend to form above unusually large and intense fires.

If a fire encompasses a large enough area (called “deep flaming”), the upward movement of hot air can cause the fire to interact with the atmosphere above it, potentially forming a pyrocloud. This consists of smoke and ash in the smoke plume, and water vapour in the cloud above.

If the conditions are not too severe, the fire may produce a cloud called a pyrocumulus, which is simply a cloud that forms over the fire. These are typically benign and do not affect conditions on the ground.

But if the fire is particularly large or intense, or if the atmosphere above it is unstable, this process can give birth to a pyrocumulonimbus – and that is an entirely more malevolent beast.

What effects do firestorms produce?

A pyrocumulonibus cloud is much like a normal thunderstorm that forms on a hot summer’s day. The crucial difference here is that this upward movement is caused by the heat from the fire, rather than simply heat radiating from the ground.

Conventional thunderclouds and pyrocumulonimbus share similar characteristics. Both form an anvil-shaped cloud that extends high into the troposphere (the lower 10-15km of the atmosphere) and may even reach into the stratosphere beyond.

NASA image of pyrocumulonimbus formation in Argentina, January 2018.
NASA

The weather underneath these clouds can be fierce. As the cloud forms, the circulating air creates strong winds with dangerous, erratic “downbursts” – vertical blasts of air that hit the ground and scatter in all directions.

In the case of a pyrocumulonimbus, these downbursts have the added effect of bringing dry air down to the surface beneath the fire. The swirling winds can also carry embers over huge distances. Ember attack has been identified as the main cause of property loss in bushfires, and the unpredictable downbursts make it impossible to determine which direction the wind will blow across the ground. The wind direction may suddenly change, catching people off guard.

Firestorms also produce dry lightning, potentially sparking new fires, which may then merge or coalesce into a larger flaming zone.

In rare cases, a firestorm can even morph into a “fire tornado”. This is formed from the rotating winds in the convective column of a pyrocumulonimbus. They are attached to the firestorm and can therefore lift off the ground.




Read more:
Turn and burn: the strange world of fire tornadoes


This happened during the infamous January 2003 Canberra bushfires, when a pyrotornado tore a path near Mount Arawang in the suburb of Kambah.

A fire tornado in Kambah, Canberra, 2003 (contains strong language).

Understandably, firestorms are the most dangerous and unpredictable manifestations of a bushfire, and are impossible to suppress or control. As such, it is vital to evacuate these areas early, to avoid sending fire personnel into extremely dangerous areas.

The challenge is to identify the triggers that cause fires to develop into firestorms. Our research at UNSW, in collaboration with fire agencies, has made considerable progress in identifying these factors. They include “eruptive fire behaviour”, where instead of a steady rate of fire spread, once a fire interacts with a slope, the plume may attach to the ground and rapidly accelerate up the hill.

Another process, called “vorticity-driven lateral spread”, has also been recognised as a good indicator of potential fire blow-up. This occurs when a fire spreads laterally along a ridge line instead of following the direction of the wind.

Although further refinement is still needed, this kind of knowledge could greatly improve decision-making processes on when and where to deploy on-ground fire crews, and when to evacuate before the situation turns deadly.The Conversation

Rachel Badlan, Postdoctoral Researcher, Atmospheric Dynamics, UNSW

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

Here’s how a 100% renewable energy future can create jobs and even save the gas industry



File 20190123 122904 1whjg0s.jpg?ixlib=rb 1.1
The gas industry of the future could manufacture and deliver renewable fuels, rather than mining and processing natural gas.
Shutterstock.com

Sven Teske, University of Technology Sydney

The world can limit global warming to 1.5℃ and move to 100% renewable energy while still preserving a role for the gas industry, and without relying on technological fixes such as carbon capture and storage, according to our new analysis.

The One Earth Climate Model – a collaboration between researchers at the University of Technology Sydney, the German Aerospace Center and the University of Melbourne, and financed by the Leonardo DiCaprio Foundation – sets out how the global energy supply can move to 100% renewable energy by 2050, while creating jobs along the way.

It also envisions how the gas industry can fulfil its role as a “transition fuel” in the energy transition without its infrastructure becoming obsolete once natural gas is phased out.




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Our scenario, which will be published in detail as an open access book in February 2019, sets out how the world’s energy can go fully renewable by:

  • increasing electrification in the heating and transport sector

  • significant increase in “energy productivity” – the amount of economic output per unit of energy use

  • the phase-out of all fossil fuels, and the conversion of the gas industry to synthetic fuels and hydrogen over the coming decades.

Our model also explains how to deliver the “negative emissions” necessary to stay within the world’s carbon budget, without relying on unproven technology such as carbon capture and storage.

If the renewable energy transition is accompanied by a worldwide moratorium on deforestation and a major land restoration effort, we can remove the equiavalent of 159 billion tonnes of carbon dioxide from the atmosphere (2015-2100).

Combining models

We compiled our scenario by combining various computer models. We used three climate models to calculate the impacts of specific greenhouse gas emission pathways. We then used another model to analyse the potential contributions of solar and wind energy – including factoring in the space constraints for their installation.

We also used a long-term energy model to calculate future energy demand, broken down by sector (power, heat, industry, transport) for 10 world regions in five-year steps. We then further divided these 10 world regions into 72 subregions, and simulated their electricity systems on an hourly basis. This allowed us to determine the precise requirements in terms of grid infrastructure and energy demand.

Interactions between the models used for the One Earth Model.
One Earth Model, Author provided

‘Recycling’ the gas industry

Unlike many other 1.5℃ and/or 100% renewable energy scenarios, our analysis deliberately integrates the existing infrastructure of the global gas industry, rather than requiring that these expensive investments be phased out in a relatively short time.

Natural gas will be increasingly replaced by hydrogen and/or renewable methane produced by solar power and wind turbines. While most scenarios rely on batteries and pumped hydro as main storage technologies, these renewable forms of gas can also play a significant role in the energy mix.

In our scenario, the conversion of gas infrastructure from natural gas to hydrogen and synthetic fuels will start slowly between 2020 and 2030, with the conversion of power plants with annual capacities of around 2 gigawatts. However, after 2030, this transition will accelerate significantly, with the conversion of a total of 197GW gas power plants and gas co-generation facilities each year.

Along the way the gas industry will have to redefine its business model from a supply-driven mining industry, to a synthetic gas or hydrogen fuel production industry that provides renewable fuels for the electricity, industry and transport sectors. In the electricity sector, these fuels can be used to help smooth out supply and demand in networks with significant amounts of variable renewable generation.

A just transition for the fossil fuel industry

The implementation of the 1.5℃ scenario will have a significant impact on the global fossil fuel industry. While this may seem to be stating the obvious, there has so far been little rational and open debate about how to make an orderly withdrawal from the coal, oil, and gas extraction industries. Instead, the political debate has been focused on prices and security of supply. Yet limiting climate change is only possible when fossil fuels are phased out.

Under our scenario, gas production will only decrease by 0.2% per year until 2025, and thereafter by an average of 4% a year until 2040. This represents a rather slow phase-out, and will allow the gas industry to transfer gradually to hydrogen.

Our scenario will generate more energy-sector jobs in the world as a whole. By 2050 there would be 46.3 million jobs in the global energy sector – 16.4 million more than under existing forecasts.




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Our analysis also investigated the specific occupations that will be required for a renewables-based energy industry. The global number of jobs would increase across all of these occupations between 2015 and 2025, with the exception of metal trades which would decline by 2%, as shown below.

Division of occupations between fossil fuel and renewable energy industries in 2015 and 2025.
One Earth Model, Author provided

However, these results are not uniform across regions. China and India, for example, will both experience a reduction in the number of jobs for managers and clerical and administrative workers between 2015 and 2025.

Our analysis shows how the various technical and economic barriers to implementing the Paris Agreement can be overcome. The remaining hurdles are purely political.The Conversation

Sven Teske, Research Director, Institute for Sustainable Futures, University of Technology Sydney

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

Suffering for science: why I have insects sting me to create a pain index


Justin Schmidt, University of Arizona

Over the past 40 years (but in reality since I was five years old), I’ve been fascinated with insects and their ability to sting and cause pain. In graduate school, I became interested in why they sting and why stings from such tiny animals hurt so much.

To answer these questions, we first needed a way to measure pain – so, I invented the insect pain scale. The scale is based on a thousand or so personal stings from over 80 insect groups, plus ratings by various colleagues.

Insects sting to improve their lives and increase their opportunities. The stings provide protection, thereby opening doors to more food resources, expanded territories, and social life within colonies. By studying stinging insects, we gain insight into our own lives and the societies we live in.

Why sting?

To say that insects sting “because they can” isn’t all that helpful. The real question is why insects evolved a stinger in the first place. Obviously, it had some value, otherwise it would have never evolved – or, if initially present, it would have been lost through natural selection.

Stingers have two major uses: to get food and to avoid becoming food for some other animal. Examples of the stinger used for sustenance include parasitic wasps that sting and paralyse caterpillars that become food for the wasp young, and bulldog ants that sting difficult prey insects to subdue them.

More importantly, the stinger is a major breakthrough in defence against large predators. Imagine, for a moment, that you’re an average-sized insect being attacked by a predator a million times larger than you. What chance would you have?

Honeybees face this problem with honey-loving bears. Biting, scratching or kicking won’t work. But a stinger with painful venom often does.

In this sense, the stinging insect has found a way to overcome its small size. The stinger is an “insect gun” of sorts – it neutralises the size difference between assailant and victim.

The insect sting pain index

This is where the insect sting pain index comes in. Unless we have numbers to compare and analyse, sting observations are just anecdotes and stories. With numbers, we can compare the effectiveness of one stinging insect’s painful defence against others and test hypotheses.

One hypothesis is that painful stings provide a way for small insects to defend themselves and their young against large mammalian, bird, reptile or amphibian predators. The greater the pain, the better the defence.

Greater defence allows insects to form groups and become complex societies as we see in ants and social wasps and bees. The greater the pain, the larger the society can become. And larger societies have advantages not enjoyed by solitary individuals or smaller societies.

Human and insect societies

Human sociality allows individuals to specialise and do a particular task better than most others. Examples of human specialists include plumbers, chefs, doctors, farmers, teachers, lawyers, soldiers, rugby players and even politicians (a profession sometimes viewed dubiously, but required for society to function).

Social insect societies also have specialists. They forage for food, tend to young, defend the colony, reproduce and even serve as undertakers removing the dead. Another advantage of societies is the ability to recruit others to exploit a large food source, or for the common defence, or to have additional helpers for difficult tasks.

Sociality also has a more subtle advantage: it reduces conflict between individuals within a species. Individuals not living in social groups tend to fight when they come in contact. But to live in a group, conflict must be reduced.

In many social animals, conflict is reduced by establishing a pecking order. Often, if the dominant individual in the pecking order is removed, violent battles erupt.

In human societies, conflict is also reduced via pecking order, but more importantly through laws, police to enforce laws, and gossip and societal teachings to instil co-operative behaviour. In insect societies, conflict is reduced by establishing pecking orders and pheromones, chemical odours that identify individuals and their place in society.

Why do we love pain?

The insect sting pain index also provides a window into human psychology and emotion. Put simply: humans are fascinated by stinging insects. We delight in telling stories of being stung, harrowing near-misses, or even our fear of stinging insects.

Why? Because we have a genetically innate fear of animals that attack us, be they leopards, bears, snakes, spiders or stinging insects.

People lacking such fear stand a greater chance of being eaten or dying of envenomation and not passing on their genetic lineage than those who are more fearful.

Stinging insects cause us fear because they produce pain. And pain is our body’s way of telling us that bodily damage is occurring, has occurred, or is about to occur. Damage is bad and harms our lives and ability to reproduce.

In other words, our emotional fear and infatuation with painful stinging insects enhances our long-term survival. Yet, we have little emotional fear of cigarettes or sugary, fatty foods, both of which kill many more people than painfully stinging insects. Fear of those killers is not in our genes.

The insect sting pain index is more than just fun (which it is too). It provides a window into understanding ourselves, how we evolved to where we are, and what we might expect in the future.


This article is the final part of our series Deadly Australia. You can see the whole series here.

The Conversation

Justin Schmidt, Entomologist, Southwest Biological Institute, University of Arizona

This article was originally published on The Conversation. Read the original article.

Palau: Marine Sanctuary and Fishing Banned


The link below is to an article reporting on a plan by Palau to ban commercial fishing and to create a massive marine sanctuary.

For more visit:
http://www.treehugger.com/ocean-conservation/palau-ban-commercial-fishing-and-become-marine-sanctuary-roughly-size-france.html

Moon National Park


The link below is to an article reporting on a proposal to create a national park on the moon – yeah, the moon.

For more visit:
http://www.natureworldnews.com/articles/2879/20130709/bill-proposes-plan-build-national-park-moon.htm

Antarctica: Ross Sea Marine Sanctuary


The link below is to an article that reports on work being done to create a massive marine sanctuary in Antarctica.

For more visit:
http://www.huffingtonpost.com/2012/09/14/antarctica-marine-sanctuary_n_1882958.html