Scope of Emissions
When we talk about carbon footprints or becoming carbon neutral, we’re talking not only about our own immediate impact on our environments, but the chain of impact that our choices and actions may have across the world.
We tend to discuss these chains in terms of emissions, with different industries, sectors, and activities contributing to varying degrees.
What are emissions?
“Emissions” refers to the release or discharge of greenhouse gases (GHGs) and other pollutants into the atmosphere, commonly caused by burning fossil fuels, industrial processes, agriculture, deforestation, and waste management. These emissions contribute to changes in the Earth’s climate system and can have various environmental and health impacts.
Greenhouse gases, such as carbon dioxide, methane, nitrous oxide , and fluorinated gases, trap heat in the atmosphere and contribute to the greenhouse effect. This effect is essential for maintaining Earth’s temperature and making it habitable, but the increase in greenhouse gas concentrations due to human activities is causing global warming and climate change.
Scope of Emissions
“Scope of emissions” is a concept commonly used in corporate sustainability reporting, carbon accounting, and climate change mitigation strategies to organise and differentiate emissions based on the activities or sectors that generate them.
The most widely recognised categorisation of emissions scope is defined by the Greenhouse Gas Protocol, a widely accepted accounting tool. It classifies emissions into three scopes:
Scope 1 emissions: These are direct greenhouse gas emissions that occur from sources owned or controlled by an organisation. This includes emissions from company-owned vehicles, on-site fuel combustion, and industrial processes.
Scope 2 emissions: These are indirect greenhouse gas emissions associated with the consumption of purchased electricity, heat, or steam. Scope 2 emissions occur outside the organisation’s operational boundaries but are a result of the organisation’s activities.
Scope 3 emissions: These are indirect greenhouse gas emissions that occur from sources not owned or controlled by the reporting organisation but are associated with its activities. Scope 3 emissions encompass a broad range of categories, including emissions from purchased goods and services, business travel, employee commuting, waste disposal, and transportation of products.
The scopes provide a framework for organisations to assess and measure their emissions comprehensively, considering both direct and indirect sources. This approach helps in identifying emission hotspots, setting reduction targets, and developing strategies to address climate change impacts throughout the value chain.
Image from Cambridge University
Energy and Gas Use by Sector
When we talk about carbon footprints or becoming carbon neutral, we’re talking not only about our own immediate impact on our environments, but the chain of impact that our choices and actions may have across the world.
We tend to discuss these chains in terms of emissions, with different industries, sectors, and activities contributing to varying degrees.
Transportation
The transportation sector includes various modes of transportation, including cars, trucks, airplanes, ships, and trains, and plays a significant role in global energy consumption and greenhouse gas emissions.
The energy used by the transportation sector primarily comes from fossil fuels, such as gasoline, diesel, and jet fuel. These fuels are burned in engines to generate the power needed for movement. However, this reliance on fossil fuels leads to the release of carbon dioxide and other pollutants, contributing to climate change and air pollution.
Efforts are being made to transition to cleaner and more sustainable alternatives, such as electric vehicles, biofuels, and hydrogen-powered vehicles, to reduce the carbon footprint of the transportation sector. Additionally, advancements in fuel efficiency, improved infrastructure, and the promotion of public transportation and active transportation modes like cycling and walking are also important for reducing energy consumption and emissions in this sector.
Industry
The industrial sector includes manufacturing, construction, mining, and chemical production, and is a significant consumer of energy worldwide, using a variety of gases for different purposes.
Fossil fuels like coal, oil, and natural gas, as well as electricity are commonly used to power industrial processes, machinery, and equipment. Natural gas combustion produces carbon dioxide (CO2), but it generally emits fewer pollutants compared to other fossil fuels. Other gases used in specific industrial applications include hydrogen (H2), which is utilised in refining petroleum and producing chemicals, as well as in the manufacturing of ammonia and methanol. Carbon monoxide (CO) is another gas used in industrial processes, often as a reducing agent in metallurgical operations. Additionally, gases like nitrogen (N2), oxygen (O2), and argon (Ar) are employed in industrial settings for purposes such as inerting, blanketing, and chemical reactions
Greenhouse gas emissions can be reduced by upgrading equipment, optimising energy efficiency, utilising cleaner fuels or renewable energy sources, and implementing advanced technologies for emissions control and capture.
Buildings
The energy used in buildings is primarily for heating, cooling, lighting, and powering various appliances and equipment, and the demand is influenced by factors such as building size, insulation, HVAC systems, lighting technologies, and occupant behaviour. The energy itself can come from various sources, including electricity, natural gas, oil, and coal. It’s worth noting that “natural gas” is a fossil fuel composed mainly of methane (CH4) and when combusted releases carbon dioxide (CO2) and smaller amounts of other pollutants.
To address buildings’ emissions, energy-efficient building design, improved insulation, energy management systems, efficient appliances, and the integration of renewable energy sources like solar panels and geothermal systems are being employed to reduce energy consumption and promote sustainability in the building sector.
Agriculture, Forestry and Land Use
In agriculture, energy is used for various activities such as planting, irrigation, harvesting, and processing. This includes fuel for machinery and equipment, electricity for irrigation systems, and energy for heating and cooling in storage and processing facilities. Similarly, in the fishery sector, energy is used for fishing operations, transportation, and processing of fish and seafood. Forestry operations require energy for logging, processing, and transporting timber and other forest products. In addition, land-use changes, such as deforestation and land clearing, can release stored carbon and contribute to greenhouse gas emissions.
The energy used in these sectors often relies on fossil fuels, and various gases are associated with different processes and activities. Methane and nitrous oxide are the primary gases of concern.
The methane emissions predominantly come from livestock, especially ruminants like cattle and sheep, during enteric fermentation and manure management. Nitrous oxide emissions primarily result from the use of nitrogen-based fertilisers and the breakdown of organic matter in soils. However, in the fishery sector, methane emissions occur from the anaerobic decomposition of organic matter in aquaculture ponds as well as waste management. Meanwhile, deforestation releases carbon dioxide stored in trees. Land-use changes can also contribute to emissions through the conversion of forests to agricultural land or urban areas.
There is a growing trend towards adopting renewable energy sources and energy-efficient practices, including solar-powered irrigation systems, energy-efficient machinery, and the integration of renewable energy technologies. Furthermore, carbon sequestration initiatives, like afforestation and reforestation, aim to offset emissions by increasing the carbon absorption capacity of forests and other ecosystems in these sectors.
