The Science of the Australian Wildfires

Although wildfires in Australia have been burning for six months, there are still another three months before the fire season is over. And so far, this fire season has been particularly bad. By some estimates the fires have consumed an area of almost 100,000 square km; to put this in perspective, this is an area larger than Vermont, New Hampshire, Massachusetts, Connecticut, and Rhode Island combined, and is 80 times the size of the 2019 California wildfires. New South Wales alone has had more land on fire this season than it has had in the previous 15 years combined.

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Source: Matthew Abbott, New York Times

People are pointing to climate change as a possible cause for the high temperatures, droughts, and increased winds that have created ideal conditions for rapid fire growth throughout the country. According to the Australian Government Bureau of Meteorology, the annual temperature in Australia is 1.5°C above the average, and about 2°C higher than a century ago. Rainfall, on the other hand, is the lowest seen in 120 years.

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Source: Robert Rohde

These changes in climate may seem small, but in combination, they can create environments conducive to fires. December 17, 2019, marked continental Australia’s hottest day on record at an average 40.9°C (105.6°F), with inland temperatures reaching as high as 44.8°C (115°F)—that is, until December 18 set new records, with an average temperature of 41.9°C (107.4°F) and a high of 49.9°C (121.8°F). Record high temperatures coupled with lower-than-average rainfall led to perfect conditions for wildfires. Additionally, strong winds only encouraged the spread of the fire and impacted firefighters’ abilities to control the blazes.
Science can play a role in not only stopping the current wildfires, but also in understanding how global climate affects local ecosystems, how local disasters affect the global community, and how to prevent future disasters.

What Can Be Done in the Classroom?

While some students may be distressed to learn about the fires in Australia, many are probably already aware of what is happening and are likely to have questions about why the fires persist and how they will affect not only Australia’s unique ecosystems but also what repercussions there may be for the rest of the world and what can be done to prevent the destruction of ecosystems by wildfires. These questions can easily be explored and discussed in middle school and high school, where NGSS classrooms will already be covering related topics, including conservation and cycling of energy and matter, interactions of molecules and air masses, repercussions of changes to ecosystems, and evaluation of global problems and designing solutions.
Here are just a few ways you can constructively discuss the Australian fires in your middle school or high school classroom, along with the NGSS standards related to each.

 

Seasons of the Hemispheres

Related NGSS Standards:
MS-ESS1-1

australia_fire_STEM_Education_Earth’s axis creates opposite seasons in the northern and southern hemispheres

Earth’s axis creates opposite seasons in the northern and southern hemispheres.
Source: Mary Crooks, National Geographic Society

Students may be confused about why the fires in Australia are occurring in December and January, while the wildfires in the U.S. typically occur in July and August. Like California, much of Australia has a burning season from late spring through the fall, due to high temperatures and low rainfall during these months. But unlike California, in Australia spring starts in September, summer starts in December, and fall starts in March, because it is located in the southern hemisphere.

 

Pollution of the Atmosphere

Related NGSS Standards:
MS-LS2-3, MS-ESS2-5, MS-ESS2-6, MS-PS1-2, MS-PS1-4
HS-ESS2-6, HS-ESS3-1, HS-ESS3-5, HS-PS1-7

Australia Fires Blog_STEM_education

The same view in Sydney before and after the smoke from the wildfires arrived.
Source: Erienne Lette

Fire may seem to destroy everything in its path, but as scientists, we know that matter is never destroyed. From a scientific point of view, the burning of trees is a chemical change that releases the greenhouse gas carbon dioxide into the atmosphere. But in addition to releasing carbon dioxide, the fires are releasing a number of other pollutants that can cause respiratory illnesses in the form of particulate matter. These particles are spread by air currents to new locations, creating smog. Smog makes seeing and breathing difficult and, in Australia, it is causing people to cancel outdoor activities and even close schools and businesses.

Due to the way heat and wind distribute particulate matter in the atmosphere, the smoke from these fires is circumnavigating the globe, turning the skies over New Zealand orange and being visible from space over Argentina.

 

Changes to the Weather

Related NGSS Standards:
MS-ESS2-5, MS-ESS2-6, MS-ESS3-2, MS-PS1-4, MS-PS1-5
HS-ESS2-4, HS-ESS3-5

australia_fire_STEM_Education_How smokes can create clouds that cause lightningmedia.bom.gov.au/social/blog/1618/when-bushfires-make-their-own-weather/

How smokes can create clouds that cause lightning.
Source: Australian Government, Bureau of Meteorology

The Indian Ocean Dipole, or the difference in ocean surface temperatures between the eastern and western sides of the Indian Ocean, changes the convection currents in the atmosphere, resulting in increased or decreased rainfall in Australia. When the temperature difference is greater between the two sides, more hot air rises near Africa, increasing the rainfall there. When these air currents then reach Australia, they are dry and cool, causing them to sink and preventing other moist air from rising, thus reducing the chances of rain. This “positive phase” of the Indian Ocean Dipole causes flooding in eastern Africa and droughts in Australia, leading to more frequent and stronger fires during Australia’s fire season.

With the burning of trees, particulate matter is being released from the biosphere into the atmosphere. These clouds of smoke are creating dangerous weather systems, including thunderstorms, which can ignite new fires. The addition of heat and particulate matter to the atmosphere can also affect surface winds and create fire tornadoes, where hot air spirals quickly upward, pulling fire with it.

 

Destruction of Food Webs and Ecosystems

Related NGSS Standards:
MS-LS1-4, MS-LS2-1, MS-LS2-2, MS-LS2-3, MS-LS2-4
HS-LS2-1, HS-LS2-2, HS-LS2-6, HS-LS4-5, HS-ESS2-2

australia_fire_STEM_Education_The food web of the kangaroo

The food web of the kangaroo.
Source: Thomas Newsome, University of Sydney

Fire is a natural part of many ecosystems, and many plants and animals have found ways to survive small wild fires. Animals will often burrow underground or move to neighboring habitats until the fires have ceased. Trees in fire-prone areas often have thick bark or tall crowns to help them survive fires. Some plants even depend on fires to spread or germinate their seeds. Fires also can help enrich soil, creating fertile land for new growth. However, fires that cover large areas make it difficult for animals to have anywhere to safely hide and can destroy plants before they can reproduce.

An Australian ecologist is estimating that up to one billion animals have died from injuries sustained as a result of these large, strong fires. This figure does not include frogs, bats, or insects, since their populations were not well documented before this fire season began. Changes to the numbers and types of animals in these food webs will have drastic effects on the ecosystems, due to loss of pollinators, planters, predators, and prey. Additionally, ash from the fires may also encourage the growth of algal blooms in nearby bodies of water, which can be harmful for aquatic ecosystems.

 

Loss of Material and Energy From the Ecosystem

Related NGSS Standards:
MS-LS2-1, MS-LS2-2, MS-LS2-3, MS-LS2-4, MS-PS1-5
HS-LS2-1, HS-LS2-3, HS-LS2-4, HS-LS2-5, HS-ESS2-6, HS-PS1-7

australia_fire_STEM_Education_One koala survivor looks for fresh water to drink while another sits in its scorched habitat

One koala survivor looks for freshwater to drink while another sits in its scorched habitat.
Sources: Pamela Schramm and RSPCA South Australia, Reuters

Additionally, the number of deceased animals will continue to grow due to loss of habitats. As particles and gases leave the biosphere through burning, energy and matter once contained in the ecosystems of Australia are lost. This loss of energy and mass will also disrupt the ecosystems because animals will have difficulty finding food, fresh water, shelter from predators, and breeding areas.

 

Maintaining Biodiversity and Protecting Ecosystems

Related NGSS Standards:
MS-LS2-5, MS-PS1-6, MS-PS3-3, MS-ETS1-1, MS-ETS1-2, MS-ETS1-3, MS-ETS1-4
HS-LS2-7, HS-LS4-6, HS-ESS3-1, HS-ESS3-3, HS-ESS3-4, HS-ESS3-5, HS-ESS3-6, HS-PS3-3, HS-PS3-4, HS-ETS1-1, HS-ETS1-2, HS-ETS1-3, HS-ETS1-4

australia_fire_STEM_Education_A rescued baby kangaroo is fed while resting in a human-made pouch

A rescued baby kangaroo is fed while resting in a human-made pouch.
Sources: Pamela Schramm and RSPCA South Australia, Reuters

Students will likely be interested to know how people have been helping animals in the ecosystem survive and recover. To combat the loss of matter and energy from one ecosystem, teams are airlifting food into the fire-ravaged habitat of the endangered brush-tailed rock wallabies that were left stranded and starving. Animal rescue groups have been taking in a variety of animals, for which crafters are making bedding, crates, and coverings.

Students may also be interested in exploring methods for avoiding similar tragedies in the future. These could include exploring how Australia’s aboriginal people at one time used controlled burning to reduce the amount of flammable materials from ecosystems and prevent widespread fires, examining the design of fireproof wildlife shelters, or investigating the science behind fire blankets and cold packs and how knowledge of these scientific properties could be used in future fire disasters.

 

Why It Is Important to Discuss This in Science Class

Classrooms are the ideal setting for providing students with the factual information relevant to their global community that will help them grow into tomorrow’s leaders. And science classes are particularly well suited to helping students address their concerns and questions about the environment in a way that will provide them with satisfactory answers.

But most importantly, current events help students understand the significance of what they learn in school, and how it applies to everyday life. Addressing current environmental issues can make students understand how their personal actions can help provide answers and solutions through scientific research and design.

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Source: Kevin Tueff

 

Sources:

  1. https://www.bbc.com/news/world-australia-50951043
  2. https://www.ft.com/content/c068339e-3c55-11ea-b232-000f4477fbca
  3. https://www.bbc.com/news/world-australia-50837025
  4. bom.gov.au/climate/change/#tabs
  5. bom.gov.au/climate/history/rainfall/
  6. https://www.bbc.com/news/av/world-australia-50991994/coming-towards-us-like-a-monster-high-winds-increase-australia-fire-fears
  7. https://www.smh.com.au/national/nsw/many-schools-close-cancel-playtime-and-sport-because-of-poor-air-quality-20191205-p53hby.html
  8. https://phys.org/news/2013-11-indian-ocean-phenomenon-extreme-weather.html
  9. https://www.washingtonpost.com/weather/2020/01/04/record-shattering-heat-strong-winds-cause-australias-bush-fire-crisis-escalate/
  10. https://www.washingtonpost.com/climate-environment/firenados-ember-attacks-and-megafires-australia-is-seeing-sci-fi-weather/2020/01/13/5e67c25c-3315-11ea-91fd-82d4e04a3fac_story.html
  11. https://www.smithsonianmag.com/smart-news/more-one-billion-animals-have-been-killed-australias-wildfires-scientist-estimates-180973926/
  12. https://www.scientificamerican.com/article/australias-bushfires-have-likely-devastated-wildlife-and-the-impact-will-only-get-worse/
  13. https://www.sciencenews.org/article/australian-fires-incinerated-habitats-threatened-species-ecological-disaster
  14. https://www.bbc.com/news/world-australia-51020384

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