Australia fires

Bushfire crisis in Australia

Print edition : February 28, 2020

Flying embers seen in Moruya on January 23. The burning pieces of tree branches, transported several kilometres away by the wind, start new fires. Ember dispersals up to 30 km have been seen. Photo: Getty Images

A raging blaze in a wooded area seen from Mount Tomah in New South Wales, Australia, on December 15, 2019. This image was obtained from a social media video. Photo: TERRY HILLS BRIGADE via REUTERS

A helicopter drops water on a fire near Bredbo on February 2. Photo: Rick Rycroft/AP

Scorched trees seen near Buchan in East Gippsland, on January 9. The Australian environment has millions of years of natural association with bushfires. Photo: Carla Gottgens/Bloomberg

Australia’s worst ever wildfires have been raging all through this summer, causing extensive loss of lives, property and businesses and devastating the environment in the country and its neighbourhood.

FOREST fires are a global phenomenon and a natural component of forest and scrubland ecosystems in arid, semi-arid, boreal and tropical environments where meteorological conditions are characterised by high temperatures and low relative humidities. It has been estimated that more than 30 per cent of the land surface is subjected to a substantial occurrence of fire, and the majority occurs in south-western United States, western South Africa, South America, northern Spain, Portugal, boreal Russia, Canada and south-eastern Australia. In recent years, extreme fire seasons have significantly impacted human lives and property and the environment in many of the above countries.

Forest fire is a general term used to describe all kinds of fires that occur in forests and the open environment. It is generally considered either a wildfire or a controlled (planned or prescribed) fire for a specific purpose. An uncontrolled fire that burns wild land vegetation, which includes grass fires and mountain fires, is across the globe generally called a wildfire, whereas in Australia it is called a bushfire. Prescribed burning of naturally accumulated leaf litter on the forest floor is a standard practice to reduce fuel levels and thereby avoid a wildfire or minimise its extent and severity. This is a regular practice before summer. Wildfires occur mostly in the summer months because of the presence of abundant dry fuel, which significantly contributes to the intensity, areal extension and severity of a fire. Although the speed of normal wildfires is slow compared with grass fires, they are severe and intense and move like tsunami waves, driven by strong winds. The radiant heat from wildfires is so dangerous that people cannot be close to it. It is difficult to put out the fire as the fire front will be hundreds of kilometres long.

Fire season

Australia is a large continent with a variable climate. A major part of the continent is either desert or has a semi-arid environment. The southern part has a temperate climate and the north-eastern part has a tropical climate. Rainfall is scarce; 80 per cent of the continent receives less than 600 millimetres (60 centimetres) of rainfall annually and 50 per cent of the area receives less than 300 mm only. The country has four seasons, each of three months’ duration, with autumn starting in March.

The Australian environment has millions of years of natural association with bushfires. For thousands of years, aboriginal (native) people used fire as a tool for hunting and to reduce the levels of fuel for easy movement through the forests. In the summer season, when the atmospheric temperature increases and humidity becomes lower, the chance of fire is more, and it may spread quickly when strong winds blow. The country is experiencing one of its worst droughts in decades, with high temperatures and 40 per cent below normal rainfall.

The summer season witnessed unprecedented bushfires, specially in the south and south-eastern regions. The State of New South Wales (NSW) has been severely affected, followed by Victoria and South Australia. This is said to be because of the higher-than-normal summer temperatures, caused mainly by the El Nino effect in the Southern Ocean, the dipole effects in the Indian Ocean, and the southern annular mode. The current fire season burned around 20 million acres (one acre is 0.4 hectare) of forests (equivalent to the area of Arunachal Pradesh) and took 28 human lives and more than a billion animal lives. The fire also burned more than 3,000 properties completely or partly, including houses and businesses, rendering thousands homeless and jobless, and impacting the economy of the country as a whole. Thousands of people are taking part in firefighting operations, many of them as volunteers. The federal government deployed defence forces to save the lives of people in the affected areas and for clean-up operations.

Many victims said fighting against the raging fire was like waging a war to protect their lives and property. As the fires raged, the sky turned orange and visibility became poor. At Lake Conjola in NSW, holidaying families were trapped as the flames engulfed the area. Many of them fled into the lake, driving cars and pulling children into the water. The smoke was so severe that visibility was reduced. The fire also damaged houses in the outer suburbs of Melbourne and Sydney, two major cities in Australia. Several fires are still burning, and it may take several weeks to put out them. The country hopes that rain will give firefighters some relief. How did a large and devastating fire form? Climate is the major factor that creates fire regimes around the globe along with anthropogenic land-use change, land abandonment and widespread planting of fire-prone species. Most of the fire regimes occur in the temperate and tropic regions with higher temperatures and low humidities in summer as seen in south-eastern Australia and south-western U.S. During the normal summer season in Australia, mercury levels go up only in February, but this summer it happened early owing to climate change, creating, for one, a situation conducive to wildfire by drying all the fuel load in the forest and the bush land. The second factor is the low relative humidity. The third factor is the presence of vegetation types that burn easily, such as eucalyptus due to the presence of oil in its leaves.

Even if the above mentioned causative factors are taken into account, there should be an immediate cause for the fire. Researchers and investigators identified several causes such as lightning strikes, power-line sparks, volcanic eruptions and human involvement in the form of arson and negligence, the throwing of lighted cigars or matchsticks, flying sparks from vehicles and agro-machines, losing control of planned burns and agri-burns, and campfires. Several hundred fires occurred in Australia this summer, with a few of them being identified as caused by human negligence and the rest by lightning strikes. When a million volts hits dry fuel in the forest in the form of a lightning spark, it burns and spreads the fire quickly, especially when the wind speed is high. If a bushfire happens in a remote area, it may take some time before anyone learns about it and responds. Inaccessibility of the wilderness and the intensity and severity of the radiant heat prevent firefighters from approaching the fire directly, so firefighting operations are carried out using water-bombing aircraft and helicopters. It is reported that in some places the flames reached a height of around 70 metres. Sometimes, two or more fire fronts may join and become a horrendous and long fire front that is difficult for firefighters to deal with.

If one wildfire starts, it can easily generate other fires in several ways; ember attacks and spot fires are significant among them. Burning pieces of tree branches can be transported several kilometres away by the wind (ember dispersals up to 30 km were noted) and start new fires. Airborne burning tree branches are called embers and the process is called an ember attack. The new fires thus formed are called spot fires, which are the main cause of the destruction of houses and vehicles in many places.

Sparks from power distribution lines are also a major factor. In 2009, 173 people died in a major fire in the State of Victoria, which started when a power distribution line snapped in a strong wind (125 km/hour). The charred materials, dust and smoke can form a special cloud called pyrocumulonimbus that can create new fires in its path of movement. The formation of fire spouts was noted in some places during the recent fires.

Bushfire impacts on society

Bushfires have a huge adverse impact on Australian society and environment, includings loss of lives and property, loss of infrastructure, economic loss owing to the shutdown of businesses, homelessness, job loss, mental trauma, and loss of millions of square kilometres of forest, millions of wild animals, and vast ecosystems.

More than 3,000 properties, which include houses, farms, industries, petrol stations, resorts, schools and hospitals, have been completely or partially burned. Most of the houses were burned right in front of their owners, who were unable to save any of their belongings as the fires were severe and the radiant heat and smoke made it impossible to approach the burning houses.

Farmers have been affected badly. In many places, the fire completely burned their farms. Batlow is the apple capital of Australia. Apple orchards have burned completely, and this may increase the price of apples and wine. The charring of cattle and sheep has hit dairy farmers and the dairy industry (one dairy unit lost products worth half a million dollars). Insurance companies will suffer, and as a result home and car insurance premiums will go up in the future. Billions of dollars worth of economic activities have suffered, including tourism.

It has been established that more than a billion wild animals, including kangaroos, wallabies, wombats, porcupines and honeyeaters, have perished. We saw burnt carcasses of animals. The defence forces had them buried. Injured animals were treated in veterinary hospitals, and animals that had no hope of recovery were euthanised. Animals that escaped the fires face problems such as lack of food and habitat and are forced to live in a threatening environment.

Impact on the environment

The scars and wounds of the fires on the Australian environment will take decades to heal completely. Bushfires alter the forest ecosystem’s structure and functions. Around 20 million acres of forest land has been lost. It may take several years to get the ecosystem back and in some places it may not even come back to its original state. Fires make substantial alterations to the physical and biogeochemical properties of the forest soil, which include a shift in the dominant invertebrate taxa, nutrient levels in the soil, and release of major and trace elements, and leave a footprint on the landscape called ash, which is the most common residue on the soil surface in burned areas.

The carbon dioxide (CO2), carbon monoxide and particulate matter (PM) generated from fires create atmospheric pollution not only in the burned area but also thousands of kilometres away. The smoke reached New Zealand within three days, returning to Australia after going round the globe, and it may take several turns as the fires are continuously burning and supplying particles and smoke to the atmosphere. The amount of CO2 formed and the loss of billions of trees are affecting the global greenhouse gas budget. Atmospheric pollution may cause several health problems, especially in people with asthma. It is already observed that in many places hospital visits have increased in the wake of the wildfires.

The PM hanging in the air will fall when the next big rainfall occurs and contaminate or pollute the environment, specifically surface water resources, generating another health concern. The concern is the presence of enormous quantities of ash and charred materials in the burned areas as many potentially toxic chemicals and contaminants may mix with the ash, which may become airborne and be carried for long distances by wind.

Soil erosion will increase up to 200 per cent as surface soil gets exposed after a fire. The fertile soil in agricultural areas will be washed away by rainfall or be carried away by wind, which will affect farmers and the growth of plants in the forest. The eroded material will fill the courses of creeks and rivers, thereby silting them and blocking the natural flow of the water. Since millions of forest bushes and plantations were burned in the wildfire, there is bound to be a big timber shortage in the near future. Studies reveal that climate change may increase the frequency, intensity and areal extent of forest fires the world over in the near future. Governments at all levels, including land managers and emergency response teams, should be equipped with new technologies to tackle forest fires and their consequences.

Dr Joji Abraham is Senior Environmental Consultant and Bushfire Researcher, Australia.