Zimbabwean authorities have been urged to establish wildland fire-fighting stations in order to respond to, monitor and rehabilitate the environment from sporadic fire incidents throughout the country which are contributing to severe black carbon emissions with negative impacts to climate and health.
According to Wilson Chimwedzi the Director of Firefight Trust, Zimbabwe has no wildland fire-fighting stations throughout its 63 districts, despite the country being ranked 30th when it comes to burnt area on the globe. Chimwedzi said that disaster management is critical including early warning systems. He has also emphasised the need for citizens to plant trees at least on a daily basis and saving trees and the environment from continued destruction. ‘Other actions which need to be initiated include the separation and re-use of waste and prevent the starting of fires,’ Chimwedzi said. According to Chimwedzi, at least 3 to 4 million hectares of trees are being burnt in Zimbabwe, despite the lack of wildland firefighting stations. He said that this is contributing to severe black carbon emissions which are contributing to global warming, climate change and have negative impacts on human health and the climate.
Black carbon is a component of fine particulate matter and consists of pure carbon in several linked forms. ‘It is formed through the incomplete combustion of fossil fuels, biofuels and biomass and is one of the main types of particles in both anthropogenic and naturally occurring soot,’ Chimwedzi said. It is also reported that black carbon has a diameter of less than 2½ microns (PM2.5) and is the most solar energy-absorbing component of particulate matter and can absorb one million times more energy than CO2. Commenting on the contribution of black carbon to global warming, Chimwedzi said that per unit of mass, black carbon has a warming impact on climate that is 460-1,500 times stronger than CO2. He says that unlike greenhouse gases, black carbon is a climate forcer which can be seen and felt. ‘Not only does it warm the atmosphere by absorbing sunlight, also dark soot that is deposited onto ice and snow speeds up melting. Black carbon stays in the atmosphere for days to weeks, but it can do a lot of lasting damage,’ he said.
He also revealed that black carbon emissions come mainly from four sources namely transport from diesel engines used for transportation and industrial use, in the residential sector from solid fuels such as wood and coal, in agriculture from open forests and savanna burning. He says that this happens both naturally and, in most cases, it is initiated by people for land clearing. The other source is from industrial processes, usually from small boilers. Explaining the effects of black carbon, Chimwedzi said that black carbon is a global environmental problem that has negative implications for both human health and our climate. He explained that inhalation of black carbon is associated with health problems including respiratory and cardiovascular diseases, cancers and even birth defects.
He added that black carbon contributes to warming by converting incoming solar radiation to heat and that its co-pollutants are key components of fine particulate matter (PM2. 5) contributing to air pollution which is reported to be the leading environmental cause of poor health and premature deaths. It is also reported that the amount of carbon emissions trapped in the atmosphere causes melting of the polar ice caps, the rising of sea levels, the disturbance of animals’ natural habitats, extreme weather events and many more negative side effects. If black carbon heats up the layer of the atmosphere where clouds are forming, they will evaporate. ‘They will no longer reflect sunlight back into space and so the soot-laced clouds end up warming the atmosphere. The clouds will act like shields, blocking incoming sunlight. Black carbon also influences cloud formation and impacts regional circulation and rainfall patterns,’ Chimwedzi said.
Other effects of black carbon outlined include affecting the health of ecosystems in several ways such as by depositing on plant leaves and increasing their temperature, dimming sunlight that reaches the earth and modifying rainfall patterns. It is reported that changing rain patterns can have far-reaching consequences for both ecosystems and human livelihoods. Notable examples include changing rain patterns which disrupted monsoons, which are critical for agriculture in large parts of Asia and Africa. The economic impacts of black carbon are also reported to be very significant. ‘The economic costs of public health stemming from black carbon are also significant. In Europe, deaths from air pollution cost the economy more than US$1.4 trillion, which amounts to almost 2% of the global economy. For the entire OECD (Organisation for Economic Cooperation Development) region, this figure is estimated to be US$3.5 trillion,’ he said.
It is also reported that currently the majority of black carbon emissions are from developing countries and the trend is expected to increase. Chimwedzi said that the largest sources of black carbon are Asia, Latin America and Africa. China and India together are reported to account for 25 to 35% of global black carbon emissions. Africa is estimated to contribute approximately 1,690 Kilo Tonnes (KT) of black carbon emissions annually. It is reported that the largest source of black carbon emissions in Africa are grassland fires, residential solid fuel use for cooking and heating according to the United States Environmental Protection Agency US-EPA in 2012. Other sources include high per-vehicle emissions from aged diesel vehicle fleets and lack of engine maintenance and poor fuel quality. Estimating radioactive forcing impacts of black carbon in Africa is challenging due to complex meteorology such as the interactions with the South Asian monsoon, errors in atmospheric model parameterization and poor understanding of emissions from the African region. ‘As a result, the weather and climate impacts of black carbon and benefits of reducing emissions in Africa are uncertain,’ Chimwedzi said. Kerosene lighting for example paraffin is also emerging as a potentially important source of black carbon. It is said that as a result, air pollution-related premature mortality is expected to increase.
Solutions lie in adoption of cleaner fuels and lower vehicle emissions and replacing the oldest and dirtiest vehicles with newer, efficient ones. ‘Governments can help millions of people breathe easier and simultaneously help combat climate change,’ he said. There is need for standards for the reduction of pollutants from diesel vehicles (including adding particle filters to exhausts) equivalent to those included in Euro-6/VI standards, for on- and off-road vehicles; replacing lump coal with coal briquettes in cooking and heating stoves; replacing traditional fuel wood combustion technologies in the residential sector in industrialized countries with wood pellet stoves that use dry fuel produced from recycled wood waste or sawdust and other transitioning to using greener fuels.
