Which human activities are major contributors to greenhouse gas emissions?

Major contributors to greenhouse gas emissions include burning fossil fuels, deforestation, industrial processes, and agriculture.

Burning fossil fuels for electricity, heat, and transportation is the largest single source of global greenhouse gas emissions. This includes the combustion of coal, oil, and natural gas. When these fossil fuels are burned, they release carbon dioxide and other greenhouse gases, which trap heat in our atmosphere, leading to global warming. For instance, coal-burning power plants are one of the largest sources, while petrol-burning vehicles also contribute significantly.

Deforestation is another major contributor. Trees absorb carbon dioxide, one of the main greenhouse gases, and convert it into oxygen through photosynthesis. When forests are cut down, not only does this carbon-absorbing process cease, but the carbon stored in the trees is released into the atmosphere as CO2 if the wood is burned or decays.

Industrial processes also contribute to greenhouse gas emissions. These include chemical reactions necessary to produce goods from raw materials. Some industrial processes release CO2 directly, such as the production of cement, while others release gases like hydrofluorocarbons (HFCs), perfluorocarbons (PFCs), and sulphur hexafluoride (SF6), which have much higher warming potentials compared to CO2.

Agriculture is another significant source of greenhouse gases. Methane, a potent greenhouse gas, is released during the production and transport of coal, oil, and natural gas. It is also emitted by livestock and other agricultural practices, as well as by the decay of organic waste in municipal solid waste landfills. Nitrous oxide, another powerful greenhouse gas, is emitted during agricultural and industrial activities, as well as during combustion of fossil fuels and biomass.

In conclusion, human activities such as burning fossil fuels, deforestation, industrial processes, and agriculture are major contributors to greenhouse gas emissions. These activities release gases like carbon dioxide, methane, and nitrous oxide into the atmosphere, which trap heat and contribute to global warming.