Wildfires are widespread phenomenon across the world. An uncontrolled destructive fire in forest land is generally termed as wildfire. A wildfire is an unregulated fire in inflammable vegetation place happening in rural areas [1]. Changes in environmental conditions influence prevalence and severity of wildfire causing longer fire seasons and wider area covered [2] [3] [4] [5]. Due to the lightning strike or carelessness of human, it started from a small place and destroys large areas of forest land, locality and harmfully effects on the environment, ecology and properties. Sometimes it causes human death also. Wildfire breaks down the abiotic and biotic components of forest ecosystem. It may be ablaze vegetation remaining both under and over ground soil. Organic matters like plant roots are also flamed up due to land fire. Ground flame can smolder for a long period yet a whole season until conditions are favorable for growth as above land fire [6]. According to the vegetation type wildfire may be known as bushfire (in Australia), desert fire, forest fire, grass fire, hill fire, peat fire, vegetation fire, or veld fire. Fire which involves low growing as like as scrub termed as brush fire. Wild fire of south northern part of Australia is known as bushfire. Desert fire occurs in desert areas where vegetation is very low. Wildfire or prescribed fire which fire up forested areas, grass, or alpine/tundra vegetation termed as forest fires.

Wildfire is not common at large scale in Bangladesh. The area of forest land in Bangladesh is very inadequate and the vegetation of the forest is not suitable for forest fire. But in some cases, it was occurred due to the human activities. In Sundarbans which is the largest mangrove forest in the world, forest fire was occurred almost every year on a very small scale due to the activities of illegal infiltrators. Indian forest land is very risky for the wildfire. A long dry season with less rainfall increases the temperature of the forest which creates the favorable condition for fires.

The main natural reasons of wildfire breakout are dry climate, lightning, volcanic eruption [7] [8]. When water loss from the soil through evapotranspiration is higher than precipitation, soil becomes dry. At these circumstances, if those dry matters come in contact with fire which is created by natural occurrences like lightning, volcanic eruption or human carelessness cause wildfire and spread destructively with the help of wind. Such conditions accelerate the inception of accidental ignition or arson giving rise to a fast moving and devastating bushfire that becomes difficult to control. The speed of fire spread in forest and grassland are 10.8 Km/h and 22 Km/h respectively [9]. Campfires, Smoking, Burning of debris, Accidents or equipment failure, Fireworks, Arson etc. are the causes of starting wild fire.

The cause of wildfires differs from place to place all over the world. Lightning is the main reason of ignition in Canada and northwest China. In Africa, Central America, Fiji, Mexico, New Zealand, South America, and Southeast Asia human activities like agricultural operation, dairy and land-conversion burning are the reasons of wildfires. In Mediterranean Basin of china human negligence is key cause of wildfires [10] [11]. Lightning strikes and human activities are jointly the main reasons of wild fire of USA and Australia [12] [13]. Coal seam fires burn in New South Wales, Centralia, Pennsylvania and different coal-sustained fires of China can also spread contiguous combustible elements [14]. Heat waves, droughts, climate convertibility for example El Nino and local weather structure such as high-pressure ridges may raise the chance and interchange the attitude of fires suddenly [15].

Dry season of Australia becomes warmer day by day, temperature increases at the rate of one degree every century which increase the recurrence and redundancy of heat waves and droughts. Three quarters of four present in total forest land of Australia is covered by Eucalyptus trees. More than hundred varieties of Eucalyptus are naturally grown where which are generally flammable and supply oil type fuel during bushfire. Large scale wildfires occurred in Siberia, Alaska, Canary Islands and in the Amazon rainforest in 2019 due to the reason of extremely hot and dry weather. The smoke comes from the fires spread on large territory and reducing air quality. In the Amazon, generally dry season is the main time for occurring forest fire.

People live in the Australian urban periphery meet different problem due to enhancing wildfire danger and the declining of biodiversity occurred because of urbanization. Significant mutual understanding was built with the help of social education methods which related with proficient knowledge in scientific way to generate mass, simultaneous aspects on danger and give a guideline to make environmental policy [16]. The general public and wild land firefighters are exposed to smoke from wild land fires in United States every year. A current research has ascertained relationship between severe wild land fire smoke expound and heart or blood vessels disease. Studies on firefighter during and after service period demonstrate harmful condition on their health due to the up taking of excess smoke [17]. Warnings consist of forthcoming wildfires to counsel about the safety. Massive number of people is indifferent about the instruction given by fire authority. Some people stay up to evacuation, while others tried to save properties and rescue others. The research pointed out three keys information for bushfire warnings but few people are not interested to obey the instruction. First one, people have to depart from risky place before fire being dangerous. Second one is homes are impossible to save during deadly period and last one is people should go as soon as possible [18].

Different studies noticed that smoke from the wildfire hold different types of harmful elements which are responsible for respiratory problem and causes large number of mortality cases among all aged mass people [19]. A combined method form of postal survey, focus group discussions and interviews with native people was done in the Mount Lofty Ranges and Lower Eyre Peninsula of South Australia. Conclusion of the research was more than 90% of local people thought that biodiversity preservation is important to take into the account during bushfire prevention policy [20]. Australian fires characteristics demonstrated huge fluctuation on inter annual and multi-decadal time balance. The result showed that ENSO (El Niño Southern Oscillation) was the main causes for inter yearly fluctuation of fire condition stated by FFDI of Australia. Experiment also noticed that social climate change was the principle reason of the incident and excess average temperatures and potentially associated fluctuation in long term rainfall patterns [21]. To hold firm the bushfire risk, fire affected countries of all over the world are trying to suppress the fire risk. But there is very little success against the fire disaster. Fire risk become more intensifies with the changes of climate. Botswana fire which was combined reason of environmental factor, policy, land use and human activity. Research stated that fire control policy on the basis of fire exercise for land use management will be worthy for locality. Methodical fire control strategies have a secured outcome on land use and climatic necessity of fire and also support to adjust environment transformation [22].

Smoke from wildfire hold upper concentration of particulate matter (PM) than urban concentration. It causes respiratory problem of millions of people. Martine and Michael conduct a study to compare between the effects of bushfire PM₁₀ (particles with a median aerodynamic diameter less than 10 mm) and background PM₁₀. The experiment showed that smoke of PM₁₀ wildfire was at least as toxic as urban background of PM₁₀ [23]. There is a significant interaction between wildfire smoke emission and particulate matter (PM_2.5) which is the reason for mortality and respiratory problem such as asthma, bronchitis, pneumonia and chronic pulmonary disease. Due to the wild land urbanization, risk from wildfire smoke increasing day by day. Fuel and smoke management have an important role for save the people from the hazard [24].

The studies gave preference on determine in vitro methods for the consequence of fire smoke [25]. Cristine and Nicholas conducted a study in 2010 to examine an external “gap” among wildfire hazard awareness and arrangements within different property-owners in country side affected by amenity guided in-migration in South Australia. Landowners were place to fetch their delegate to bushfire preparation in the connection into daily works, dilemmas and tradeoffs [26].

For the identification of abundance mortality and financial value of wildfire in USA over several years, Neal and his team conducted a study. Northern side of California, Oregon and Idaho in the west and Florida, Louisiana and Georgia the east were dangerously invaded by wildfire. Short term financial loss is between $11 and $20 B per year with net current value of $63 B and long-term economic damage remains between $76 and $130 B every year, with net current value of $450 B [27].

A research was conducted by Thayaparan focused in re-building program of the Victoria bushfire in 2009 indicated the role of participants like formal and informal were the social-psychological measurement for economic sustainability [28]. Fire generates pyrogenic matter like charcoal by the changing of ecosystem carbon cycling. In a eucalypt forest in eastern Australia, for the research soil carbon, charcoal and nitrogen dynamics are inquired in the peak 20cm of a sandy soil. Fire removed litter but enhance the charcoal and non-charcoal SOC element together of the soils. It attributes to upper soil charcoal production and causes under-ground root mortality by incorporating soil profile. Charcoal was discriminately retained in the sandy soil that restricts the various stabilization procedures so that the inflow of dead root carbon had no effects. Charcoal incorporation and holding of the soil profile are very meaningful to carbon cycling. Charcoal increases the fire frequency of sandy soils. This effect is not only limited for upper 20 cm of soil [29]. Wildfire can cause water repellency and burn plant canopy, surface plants and litter can change organics into soil. Soil moisture, structure could be changed and infiltration can increase surface runoff, erosion. Sediment transport and deposition is enhanced. Organic matter mineralization, root uptake obstruction and reduced water quality by improving temperatures and nutrient concentrations. Artificial large and severe wildfire effects on water harmfully skewed [30].

Every year, around 30 - 46 million/km² (approx. 4% the global land surface) of the world’s land surface is being burned [31] shown in Figure 1. Greece, Italy, France, Spain and Portugal are investing annually around 2500 million euro in total for fire management especially for the detection and suppression of fire [32]. In Canada, on an average US$531 million was spent annually during the year from 2000 to 2010 for the prevention and preclusion of wildfire [33].

About 420 million years ago during Silurian period rhyniophytiod plant fossils that conserved as charcoal was the first filed wildfire. The charcoal abundance

during Middle and Late Devonian was related with low atmospheric oxygen [35] [36]. Because of increasing global warming rate firing and its destructive impacts increase day by day (Table 1).

Australia is a wildfire amenable area. Bushfire was mainly occurred in South-eastern and South-western part of Australia during the season of summer and early autumn. The most bushfire affected area in Australia is the South-east and South-west region of the country [38] [39]. At present, annual land area burnt in Australia is around 5% which is considered to be devouring nearly 10% of the net primary productivity of the continent [40]. In North of Australia, bushfires generally happened during winter which is the dry season. In 2019-2020, a catastrophic bushfire commenced at mid-June in 2019, and it is still now burning in hundreds of places of different part of Australia especially in the South-east of the continent. In 2019, fire in New South Wales started much earlier than the previous years and since September, 2019 it covered 2.7 million hectares to be burnt. This year the affected area was three times larger than that of the Amazon (906,000 hectares) fires occurred in 2019. As the recorded data of 14^th January 2020, fires burnt about 18.6 million hectares, destroyed over 5900 buildings and killed many people [41]. NASA calculated that 337 million tons of CO₂ was emitted during this firing [42]. Forest of Eastern, North-eastern Victoria, New South Wales and the Australian Capital Territory were deadly burnt. State of emergency was declared by the authorities for these states shown in Figure 2.

About 480 million mammals, birds, and reptiles were destroyed since September by bushfire and later expanded to a billion was estimated by The University of Sydney [44]. Thousands of species of extinct plants were burnt.

Source: [37].

(Table 2) New South Wales, Northern Territory, Western Australia, Queensland and victoria were being terribly damaged. Though the fire stopped in some places after the rain of January but in many places, fires are still alive like New South Wales. Even Canberra the capital is still at risk of burning. Australia spends around $375 million every year in the management of bushfire with a rise in costs of 2.2% per year [45]. Around $8.2 million was spent for Sydney health services due to bushfire in the year of 2011, and it is estimated to increase its demands on health resources in the near future [39] [46].

According to annual climate statement 2019, it was the warmest year in Australian History (Table 3). During 2019, the average increasing temperature of Australia was 1.52˚C and the previous record was +1.33˚C in the year of 2013. The maximum and minimum mean increasing temperatures were recorded 2.09˚C and 0.95˚C respectively.

Source: [37].

**Highest record; *Second Highest record.

Figure 3 demonstrated the rainfall data of Australia from the year of 1970 to 2019. Data of rainfall has been represented every 2 year interval. At the very beginning of the time span, rainfall was nearly 400 cm with its rising trends. It reached its peak in the year of 1974 i.e. about 750 cm. The rainfall pattern demonstrated a sharp decrement up to 1977 and a fluctuating trend remained till 1994 made it as the driest year. Again, there was a rising trend of rainfall reaching 700 cm in 2000 and 2010 [47].

The lowest rainfall was observed in the year of 2019 and it was remarkably low as reached about 280 cm rainfall annually. Such a dry season with minimum rainfall may be a potential cause of bushfire in Australia (Figure 3).

The temperature of Australia exposed a wide range of variation from the year of 1970 to 2019 (Figure 4). All over this time span, average temperature was fluctuating frequently ranging from −0.75˚C to +1.5˚C. The lowest average temperature was recorded in the year of 1976 falling to −0.75˚C and the highest was reported in 2019 reaching to +1.5˚C. It was always below +1˚C before the year of 2005. However, in 2005 it crossed +1˚C for the first time and in 2019 it reached the highest temperature at the rate of +1.5˚C (Figure 4), and such a high increasing temperature could have a positive impact in occurring bushfire in Australia.

The year started with rainfall scarcity across massive areas of eastern Australia. The unexpected less precipitation throughout 2019 caused severe moisture deficiencies. The Murray-Darling Basin was the main sufferer as an area of the low moisture content. The average annual soil moisture recorded in five of the 26 river catchments of the Basin was the lowest during the year 2019.

Scarcity of moisture in soil restricted the surface runoff. Winter to spring is mainly the repletion time for water storages for Southern and Southeastern Australia. Limited river flow since last three years and less runoff caused marginal fill-up to storages across the Southern Basin by the year and no significant undercurrent in the Northern Basin where storages was close to zero.

At the end of 2019, moisture storage had declined to less than 7% in the Northern Murray-Darling Basin. In the Northern Basin water storage condition was lower than any time during the Millennium Drought (2001-2009). In the Southern Basin 53% volume of moisture storage in January down to 39% at the end of April 2019 which was the irrigation season.

The storages had prolonged 47% by the end of the recovery time and diminished once again from spring to summer. Effect of the below average rainfall during reserving period also affected coastal New South Wales, Eastern South Australia, Eastern Victoria, Northwestern Victoria, East coast and North coast Tasmania and the South West part of Western Australia (Table 4).

The highest daily record of FFDI values for spring was experienced in areas of all States and Territories of Australia (Figure 5). Across northern Australia, the Grassland Fire Danger Index (GFDI) is more routinely used to assess fire weather conditions. Nevertheless, several fires started across northern Australia with FFDI values the highest was record for spring across the large areas.

Source: [47].

The bushfire or forest-fire is known as the decimation of nature by landscape fires raging out of control. The bushfire problem has no specific solution. Combination of social governance, public and personal land management, suppression efficiency and personal arrangement are one of the partial solutions. To reduce the hazard needs proper land regulation, sufficient funding and the permanent vigilance of all sides.

Wildfire is a common phenomenon from historical period, with the change of climate and environment increase the rate of damage from natural disaster. It supplies more CO₂ to the earth which is the main factor for greenhouse effect. Wildfire is not fully curable but worry about the disasters helps us to reduce the adverse effect. The average temperature of the world is increasing every year. Glaciers are melting which raises the sea level. Every year a lot of lands go under the water that increases the salinity of the soil. Salinity reduces the soil fertility and production of food, queered the food safety. To minimize the causality of the disaster we should have to be wake up together. Long term plan should be formulated. We have to change our mentality to save the world. If the change not started from our own door, it is impossible to change the world.

The authors declare no conflicts of interest regarding the publication of this paper.

Haque, Md.K., Azad, Md.A.K., Hossain, Md.Y., Ahmed, T., Uddin, M. and Hossain, Md.M. (2021) Wildfire in Australia during 2019-2020, Its Impact on Health, Biodiversity and Environment with Some Proposals for Risk Management: A Review. Journal of Environmental Protection, 12, 391-414. https://doi.org/10.4236/jep.2021.126024