Burning Biomass releases large quantities of gaseous pollutants and aerosol particles into the atmosphere, which has a substantial influence on the quality of the air we breathe, as well as on human health and the rate at which climate is changing. Burning Biomass involves combusting both living and decomposing plant matter. It encompasses both naturally occurring fires caused by lightning and fires set intentionally by humans for the purposes of land clearance and changing land usage.
Burning Biomass is the combustion of both living and dead plant matter. It encompasses both human-caused burning of vegetation for land clearing and land-use change and lightning and Jhum cultivation caused fires.
Types and Sources of Burning Biomass
Basically, there are use four major sources of biomass— wood and agricultural products, solid waste, landfill gas and biogas, and alcohol fuels (like Ethanol). Most biomass used today is home grown energy. Wood logs, chips, bark, and sawdust contribute around 44% to biomass energy. However, any organic material can provide bioenergy. Other sources of biomass include agricultural byproducts, such as fruit pits and corncobs.
According to the findings of scientists, people are responsible for approximately ninety percent of the burning of biomass, with only a small percentage of the overall number of plants burned being contributed by natural fires. When vegetation is burned, enormous quantities of particulates (solid carbon combustion particles) and gases are produced. These gases include greenhouse gases, which contribute to the warming of the planet. The emission of greenhouse gases into the atmosphere may hasten the warming of the planet or the acceleration of human-induced climate change. Studies indicate that the amount of biomass burned on a worldwide scale has increased during the past one hundred years and that a hotter earth as a result of global warming would lead to more frequent and larger fires. When particulates from the Burning Biomass are breathed in, they can have an effect not just on the climate but also on human health, in particular on the respiratory system. Emissions caused by the Burning Biomass have a substantial impact on the atmosphere and climate of the planet because fires release carbon dioxide, which is a primary greenhouse gas. Burning Biomass has environmental repercussions that can be felt both immediately and over the course of time. Through the process of photosynthesis, plants are able to store carbon dioxide over time, which enables them to function as a sink or natural storage place for the gas. When something is burned, it can release carbon dioxide into the atmosphere that has been stored for hundreds or even thousands of years in a matter of hours. Burning will also irreversibly damage an important sink for carbon dioxide if the flora is not restored after it is consumed by the fire.
Due to the radiative forcing effects that black carbon particles in the atmosphere have on the climate system and the relationship with harmful impacts on human health, there has been a lot of emphasis focused on these particles in recent years (World Health Organization, 2012). Black carbon aerosols have an effect on the Earth's radiation budget both directly and indirectly. Directly, they accomplish this by absorbing radiation; indirectly, they change cloud formation and the albedo of the surface, particularly in regions that are covered in snow and ice. The microphysical properties of black carbon change depending on the sources of the carbon and the processes that occur in the atmosphere. The combustion of biomass is the primary contributor of black carbon aerosols to the atmosphere, accounting for approximately 42 percent of the world's total black carbon emissions. Other sources of black carbon include the combustion of fossil fuels and biofuels, which contributed around 38 and 20 percent, respectively, of the total black carbon emissions. Biofuels are a renewable source of energy. Black carbon is regarded as an effective tracer for activities involving the Burning Biomass because of the large contribution it receives from sources that involve the burning of biomass. Carbon monoxide, sometimes known as CO, is a trace gas that is present in the atmosphere of the Earth and has a number of effects on the chemistry of the atmosphere, the climate system, and public health. Through its interactions with several other pollutants in the atmosphere as well as photochemical processes, it contributes to the creation of tropospheric ozone (O3) as well as aerosols. Another type of greenhouse gas, carbon monoxide (CO) has a negligible direct impact on the radiative heating of the earth's surface. In addition, large concentrations of carbon monoxide are harmful to human health. It does this by combining with hemoglobin, which in turn decreases the blood's capacity to carry oxygen. When biomass is burned, a significant amount of ozone precursors is released into the lower atmosphere. This source can drive ozone production on a regional scale, but the impact that it has on ozone levels in the global troposphere is not well constrained. After carbon dioxide and methane, ozone is the third most important anthropogenic greenhouse gas, but it has a larger uncertainty in its radiative forcing. This is in part due to the uncertainty in the source characteristics of ozone precursors, such as nitrogen oxides and volatile organic carbon, which directly affect the chemistry of ozone formation. The health of humans and ecosystems is also badly impacted by ozone in the atmosphere.
The amount of biomass produced is mostly influenced by climate, temperature, soil condition, and surplus land area. Agricultural land, forestland, and urban areas make up the majority of Bangladesh's land use types. The agriculture and forestry industries have a significant role in reducing the fuel needs of rural residents. In 2003, biomass wastes such as firewood, agricultural, and tree accounted for nearly 80% of the energy consumption in rural regions, according to research. Bangladesh's climate is favorable to the cultivation of biomass plants. Common sources of biomass in Bangladesh include agricultural crop residues, wood residues, animal waste, and municipal solid waste, among others. One of the studies revealed that biomass combustion is also responsible for black carbon emissions in the city of Dhaka. Burning dried leaves for heat in the winter is a widespread practice here. The rubbish dumps have been regularly emitting black smoke despite the fact that the government discourages such burning. Using wood for cooking is a prominent example of biomass combustion. Despite this, 70% of rural family cooking is still dependent on biomass. Due to incomplete combustion, biomass burning in a traditional clay stove is a significant source of air pollution. The typical cooks in a traditional household structure and toddlers are the principal victims of indoor air pollution in this country. A briquette is a piece of flammable material that is used to keep and operate a fire. Biomass briquettes serve a crucial role in supplying rural Bangladeshis with cooking fuel also air pollution. Sulfur is one of the principle pollutants that decompose into Sulphur dioxide. The released Sulphur dioxide stimulates nucleation processes, such as the change of gas into particles. As a result of nucleation occurrences, there is a sudden increase in air pollution. Bangladesh is a fast-developing Southeast Asian nation, but around 80% of the population still resides in rural areas. The majority of cooking in rural Bangladesh takes place in indoor surroundings with limited ventilation. As primary cooking fuels, about 70% of them use rice husk, straw, cow manure, jute stick, bagasse, bamboo, dried leaves, and wood. Massive quantities of particulate matter (PM), harmful gaseous pollutants (NOX, SOX, CO, VOC, etc.), and heavy metals are produced by the combustion of biomass (Pb, Cu, Co and Zn etc.). The production of these pollutants is strongly affected by the site of the kitchen, the types of fuel used, and the ventilation system.
However, the majority of the contaminated air that is brought inside the home in the city comes from the outside. The air quality is typically higher outside due to factors such as ventilation and weather conditions than it is inside, because once the contaminated air enters the home, there is no way for it to leave on its own.
Burning trees in brick kilns is a contributor to air pollution. At the typical daily use of wood for burning ranges from seven to fourteen ton. At its lowest point, it requires seven-ton worth of wood every single day. And since these woodlands are being burned, the environment is becoming more contaminated, which in turn is leading to an increase in a number of ailments. According to studies conducted by the Center for Atmospheric Pollution Studies, biomass burning causes a significant quantity of air pollution, which in turn affects the air quality and increases the prevalence of various types of diseases among humans. The Chittagong Hill Tracts defined an aim of Jhum cultivation in 25 hilly stations from Chaitra to Baishakh each year. In the green hills, a few inches of the topsoil have been consumed by fire. This is a significant contributor to biomass burning pollution.
Global warming is currently one of the most significant concerns. Global warming or the greenhouse effect is an environmental concern that focuses on the possibility of global climate change as a result of increased greenhouse gas concentrations in the atmosphere. This indicates that when biomass is burned, a greater proportion of harmful pollutants, such as carbon emissions, nitrogen oxides (NOx), and sulphur dioxide. Biomass emits noncombustible ash particles into the environment, which are absorbed by the atmosphere and contribute to air pollution. In addition, the bulk of electricity is generated by power plants that use nonrenewable fossil fuels such as coal, oil, and natural gas. According to the majority of experts, this adds to global warming.
There is significant evidence that breathing fine particulate matter resulting from combustion of Burning Biomass has negative health impacts. Epidemiological research suggests that short-term exposure exacerbates cardiovascular and pulmonary disease and increases the likelihood of developing symptoms, requiring medical care, or even dying. It suggests that repeated long-term exposure increases the risk of chronic respiratory and cardiovascular illness. Recent research has evaluated putative molecular routes linking exposure to fine particulate matter to cardiopulmonary morbidity and mortality. Particles from the combustion of fossil fuels such as coal, diesel, and gasoline, as well as high-temperature activities such as smelters and steel mills, contribute to regional and urban air pollution, which has been consistently linked to cardiopulmonary health impacts. Particles resulting from the combustion of biomass, including wood, other flora, animal wastes, sugar cane, etc., are also linked to detrimental health impacts. Tobacco smoke is another prominent and well-studied source of fine particles from plant materials or biomass. Environmental exposure to particles from tobacco burning can have cardiovascular and pulmonary health impacts. Fine particulate matter (PM2.5) can have both short- and long-term adverse impacts on health. Long-term exposure to PM2.5 is associated with shortened life expectancy and higher mortality risks associated with lung cancer and cardiovascular disease. The proportion of lung cancer cases that may be attributed to environmental factors such as air pollution varies from country to country and is difficult to quantify. Recent research conducted by the Lancet Commission on Pollution and Health indicates that increasing air pollution and lead poisoning kills almost nine million people annually. About three-quarters of them perished due to air pollution, with lead poisoning being the leading cause of death.
Law and Regulation
The Bangladesh Solid Waste Management Regulations 2021 were published on December 23, 2021, in accordance with the Bangladesh Environmental Protection Act of 1995. The Regulations define the responsibilities of businesses involved in solid waste management and impose collection, recycling, and disposal obligations on manufacturers of non-biodegradable products such as glass, plastic, and bottles in accordance with Extended Producer Responsibility (EPR). The regulations also include provisions for solid waste treatment, including composting and energy recovery.
Air pollution control and biomass utilization policy must be implemented effectively. Steps should be taken to preserve environmental equilibrium and air quality. To preserve the environment's stability, everyone must contribute from their individual position. The government must enhance guidelines otherwise it is difficult to stop Burning Biomass and a major catastrophe will strike the next generation.
The writer is the Dean, Faculty of Science; Chairman, Department of Environmental Science, Stamford University Bangladesh and Joint Secretary, Bangladesh Poribesh Andolon (BAPA)