What are the primary sources of greenhouse gas emissions globally?
The primary sources of greenhouse gas emissions globally are the burning of fossil fuels (coal, oil, and natural gas) for electricity, transportation, and industrial processes. Other major sources include deforestation and land-use change, especially in tropical regions. Additionally, agricultural activities such as livestock farming and rice cultivation release significant amounts of methane, a potent greenhouse gas.
Long answer
The main contributor to greenhouse gas emissions globally is the burning of fossil fuels for energy production. Coal, oil, and natural gas are widely used in electricity generation, heating systems, transportation vehicles (cars, trucks, ships, airplanes), as well as various industrial processes. When these fossil fuels combust, carbon dioxide (CO2) is released into the atmosphere.
Deforestation and changes in land use are another crucial source of greenhouse gas emissions. Forests act as carbon sinks by removing CO2 from the atmosphere through photosynthesis; however, when forests are cleared for agriculture or urbanization purposes or degraded by logging and wildfires, large amounts of CO2 are released back into the atmosphere. This process contributes significantly to global emissions.
Agricultural activities also generate substantial greenhouse gas emissions. Livestock farming is responsible for releasing methane (CH4) produced during enteric fermentation in ruminant animals (such as cows) and during manure management. Methane has a much higher warming potential than CO2 over shorter timescales. Rice cultivation emits methane too due to anaerobic conditions in flooded rice paddies.
Other significant sources include industrial processes related to cement production, steel manufacturing, chemical production (including chlorofluorocarbons), and waste management practices that produce methane from landfills.
Although these sources vary across countries based on their energy mix and economic activities, curtailing greenhouse gas emissions requires transitioning to cleaner energy alternatives like renewable sources (solar, wind), improving energy efficiency measures in industries and buildings at large scale while promoting sustainable land-use practices, and adopting climate-friendly agricultural systems.