As the year 2019 draws to a close, bringing to an end a politically turbulent decade, a particular natural phenomenon continues to dominate news headlines across the world. At the time of writing, bush fires, forest fires and grassland fires are wreaking havoc in southern and eastern Australia, in the states of New South Wales, Queensland, South Australia and Victoria. Throughout this year, wildfires have devastated large tracts of land in the Brazilian Amazon rainforest, in California, in Central Africa (Angola, Democratic Republic of Congo), in Indonesia, as well as in the boreal forests of the Northern Hemisphere, which extend from western Alaska, through Northern Canada and Greenland, all the way to eastern Siberia.
Wildfires are not new in Australia, and have indeed been a normal part of the natural weather cycle in that country. Bushfires have contributed to the natural processes by which the landscape continues to evolve and regenerate, as part of the Australian ecosystem. What is different about the situation today is the increased frequency and severity of the wildfires raging across the vast continent.
Bushfires and grassland fires require a source of ignition, a fuel, and strong winds and a continuing supply of oxygen to enable propagation. Fires can be initiated by natural phenomena, most commonly lightning strikes, as well as by human actions. Man-made fires can be either accidental or deliberate-the result of arson, and are commoner near populated areas. The fuel is mostly provided by dry vegetation, including fallen bark and leaf litter. The process of preventive hazard-reduction back-burning refers to the deliberate and controlled burning of this forest litter in order to prevent fires from developing and propagating. This fuel load is often made higher by a preceding period of rainfall, which allows the growth of plants and trees. Specifically, native Australian plants, such as the oil-rich eucalyptus, are highly combustible. Contributory factors in Australia in 2019 include high temperatures, associated with the hottest summer on record, and coexisting severe drought conditions. It doesn’t help that around seventy percent of the Australian landscape is classed as either arid or semi-arid.
The most dangerous forms of bushfire have been associated with firestorms. Massive, fast-moving and high-energy blazes of fire generate plumes that can rise high into the atmosphere and form so-called “pyrocumulonimbus” clouds. Thunderstorm-like winds can carry fiery embers widely and rapidly disseminate the fire along multiple fronts.
Inevitably, wildfires have been linked with the wider issue of climate change. While greenhouse gas emissions do not directly cause bushfires, global warming appears to have contributed to higher than usual ambient temperatures and to a loss of moisture from the land and air. Climate scientists have also identified several warning signs of the present crisis from meteorological data, such as in the form of the Indian Ocean Dipole and the Southern Annular Mode.
Climate activists have taken the opportunity to cite Australia’s role as one of the highest per capita emitters of greenhouse gases in the world. Australian politicians, in particular, remain largely supportive of the coal industry, which is a major source of carbon dioxide. Australia is the world’s largest exporter of coal (as well as liquefied natural gas) and coal-fired power provides around 60 per cent of Australia’s electricity supplies. As events develop, however, it appears that many sections of the Australian public are becoming increasingly aware of the impact of climate-related issues in their lives and are seeking solutions for the future.
Similar tensions have been seen following the Brazilian Amazon rainforest fires, as demonstrated in a widely publicised exchange of words between Brazilian President Jair Bolsonaro and French President Emmanuel Macron in August this year. There has been widespread deforestation in Brazil, with destruction of valuable rainforests, in a process of economic “development” that is directly in conflict with the longer-term need to conserve valuable natural resources. Thus, land has been cleared to provide timber for loggers, pasture for grazing beef cattle, land for the cultivation of crops such as soybean, as well as to facilitate mining activities. These processes have had a negative impact on many indigenous people, who have traditionally lived, hunted and gathered within the forest. Once again, the whole issue has been framed as a conflict with Brazil’s right to deal with the resources contained within its own territories versus wider global concerns about the effects of deforestation and forest fires, which are often initiated deliberately in the country.
In the meantime, Australia is facing up to immense pressures, caused by a loss of both human life and wildlife (bats, cattle, horses, koalas), as well as the widespread destruction of residential property and loss of agricultural land (farms, ranches, vineyards). A state of emergency has been declared in those areas most severely affected. Entire communities, such as the village Balmoral in New South Wales, have been devastated. The emissions of greenhouse gases have risen sharply. Dense smoke has led to environmental pollution and health issues, even affecting cities such as Sydney. Intense heat has also led to a range of heat-related illnesses. Firefighting efforts have sometimes struggled to keep up, even with the help of voluntary firefighters and the introduction of firefighting staff from abroad, and their efforts have been compounded by shortages of water. In the aftermath of these events, the reconstruction of infrastructure and a re-evaluation of insurance risk are likely to prove to be major challenges.
One hopes that once Australia gets over the present crisis, the nation’s land management practices will be reviewed, with the aid of any new insights that may have been gained following the present tragedy. Also, the Australian government will likely be expected by the Australian public, as well as the wider global community, to demonstrate re-invigorated climate leadership.
Ashis Banerjee