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CONCEPT – AUSTRALIAN BUSHFIRES
Read more on - Polity | Economy | Schemes | S&T | Environment
- A regular feature: Bushfires in Australia are not abnormal, and impact extensive areas. More than 800 people have died since 1851, and crores of animals have perished.
- What is 'bushfire': The word "bushfire" refers to the "bush", the sparsely-inhabited regions. These are uncontrolled, non-structural fires burning in a grass, scrub, bush, or forested area. Since Australia is a geographically and meteorologically diverse continent, it has many types of bushfires. There are two main categories -
- Hilly/mountainous fires – these burn in hilly, mountainous or alpine areas which are usually densely forested. The land is less accessible and not conducive to agriculture, thus many of these densely forested areas have been saved from deforestation. The steep terrain increases the speed and intensity of a firestorm.
- Flat/grassland fires – these burn along flat plains or areas of small undulation, predominantly covered in grasses or scrubland. These can move quickly, fanned by high winds in flat topography, and quickly consume the small amounts of fuel/vegetation available. They rarely reach the same intensity seen in major firestorms as the land is flat, the fires are easier to map and predict, and the terrain is more accessible for firefighting personnel.
- Using the bushfires: Some of Australia's native flora have evolved to rely on bushfires as a means of reproduction – for example grass trees following fire duress will send up large flower spikes to assist in procreation of the species, however the mother plants usually die off the following season. The indigenous Australians have used fire to clear grasslands for hunting and to clear tracks through dense vegetation, however this was only in periods of high rainfall and in very small grassland zones bordering desert. The food thus gained provided much needed protein to nomadic tribes.
- Reasons: Bushfires can be caused by natural causes such as lightning, or by man-made events such as arcing from overhead power lines, arson, accidental ignition in the course of agricultural clearing, grinding and welding activities, campfires, cigarettes, machinery sparks, and controlled burn escapes. They spread based on the type and quantity of fuel that is available. Fuel can include everything from trees, underbrush and dry grassy fields to homes. Wind supplies the fire with additional oxygen pushing the fire across the land at a faster rate.
- 2019 bushfires: A changing climate may be contributing to the ferocity of the 2019–20 fires with hotter, drier conditions making the country’s fire season longer and much more dangerous. Strong winds promote the rapid spread of fires by lifting burning embers into the air. This is known as spotting and can start a new fire up to 40km downwind from the fire front.
- Climate Change: While Australia has always experienced bushfires, these massive, destructive fires appeared to be occurring more frequently in the last 20 years or so. Climate change is real and acting as an enhancer. Fires are becoming more and more savage, and they are more frequent. They used to happen every 30 or 50 years, now they seem to be happening by the decade. When it comes to the current fires, historically January and February were the “blow out months” when large fires were more likely but these fires had started early, with some burning since October, and would likely continue. Australia and other countries may need to reconsider how they approached fire management as it was impossible for firefighters to 100 per cent control these large, intense fires.
- Carbon sinks no more: Until the 2019–2020 Australian bushfire season, the forests in Australia were thought to reabsorb all the carbon released in bushfires. This meant the forests achieved net zero emissions. But global warming is making bushfires burn more intensely and frequently and the current fires have already released about 350 million tonnes of carbon dioxide – as much as two-thirds of Australia's average annual carbon dioxide emissions (530 million tonnes) in just three months. These bushfire emissions increase Australia's contribution to global greenhouse gas emissions, exacerbating the problems associated with global warming.
- What is Indian Ocean Dipole (Indian Nino): Southern Australia’s temperatures have risen about 2.7 degrees Fahrenheit since 1950. Conditions over the past 20 years have been hotter and drier than in the 20 years before that. December 2019 saw the nation’s hottest day on record, an average of more than 107 degrees Fahrenheit. A major factor worsening Australia’s fire season is a natural cycle known as the Indian Ocean Dipole, which can make water in the western Indian Ocean warmer and in the eastern Indian Ocean cooler. This results in less rainfall over Australia. This phenomenon has dried out the nation for two years. Though it is too early to quantify any link between climate change and the dipole’s recent behavior, scientists have
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