Greenhouse gases catch heat from the sun and heat the planet. Over the past 150 years, human activities have been almost solely responsible for the growth of greenhouse gases in our surrounding environment. The top five countries that emit carbon dioxide are China, America, India, Japan, and Russia.
CO2 is not the only greenhouse gas causing global warming. But several other gases, are methane, nitrous oxide, and some rare gases, such as fluorinated gases, have contributed to significant warming in our atmosphere. An essential difference between these gases is their different global warming potential.
At a global level, the primary causes of greenhouse gases emission are electricity and heat, with a contribution of 31%, agriculture at 11%, transportation has 15%, forestry contribute 6%, and manufacturing contributes 12%. Overall, energy production in all forms accounts for 72% of total greenhouse gas emissions.
The transport department produces the most significant percentage of greenhouse gases, about 15%. Transport accounts for about a fifth of global CO₂ gas emissions. The remaining 29.4% of the emission comes from road trucks. Greenhouse gases from the transportation sector come from burning fossil fuels to drive cars, trucks, ships, trains, and airplanes.
A major part of this emission comes from public transport vehicles such as self-owned cars and buses, contributing to 45.1%. The remaining 29.4% of the emission arise from road trucks.
Between 1990 and 2020, greenhouse gas emissions from the transport sector increased in fixed terms more than in any other field. Transportation of a country is the most dependent on fossil fuel combustion of an industry and will account for 37% of total CO2 emissions from consumption departments by the end of 2021.
Even with the expected growing transport demand, the overall net zero scenarios require that the transport sector emissions decrease around 20% to 6 Gt by 2030.
Greenhouse gas emissions from transportation can be reduced by using up-to-date technologies, designs, and building materials for fuel-efficient vehicles, reducing travel demand, and following the slogan of walking more and driving less.
Emission from electricity production
The power sector of an economy includes the generation, transmission, and distribution of power. Carbon dioxide constitutes the most significant part of emissions, with small amounts of methane and nitrogen oxide gas from the transport department. During the combustion of fossil fuels such as coal, oil, and natural gas, these gases are released to generate electricity.
Carbon dioxide emissions from burning fossil fuels to generate power and electricity are about 34 billion tons per year. Of that, about 45% is from coal, 35% from oil, and almost 20% from natural gas. From the US electric power sector, in 2021, carbon dioxide (CO2) emissions will be 1,551 million metric tons.
According to the University of California, atmospheric emissions from electronic devices and their associated e-waste increased by 53 percent between 2014 and 2020, with 580 tons of carbon dioxide in 2020 alone. These emissions can be reduced by using renewable energy sources such as sunlight and wind rather than fossil fuels to generate power.
These greenhouse gases are also released from various chemical processes to produce electricity or heat by fuel combustion or leakage during chemical reactions and pieces of equipment.
These gases are also released from the combustion of fossil fuels in a power plant to generate electricity, which industrial power plants then use to power buildings and machinery.
Almost 47% of carbon dioxide emissions are energy-related, and most greenhouse gases (GHG) are processed gases.
Industrial process emissions are products of processes that convert raw materials into a wide range of chemical, mineral, or metal products such as cement, fertilizers, and explosives. They also include emissions of synthetic gases such as those used in refrigeration and air conditioning.
Human emissions have increased carbon dioxide by about 50% over industrial levels. Greenhouse gas emissions in the 2010s were 56 billion tons per year, higher than in the previous decade.
We can reduce emissions from the manufacturing sector by making industrial products from such materials that can be reused or renewed again and again and by developing more efficient industrial technologies.
Commercial and residential emissions
A defined part of greenhouse gases mainly come from fossil fuels burned for heating purposes, using other natural gas products, and waste management at commercial and residential places. Household waste sent to landfill emits methane gas by biodegradation of vegetation waste. Sewerage treatment plants emit methane and nitrous oxide gas. Anaerobic digestion in biogas plants also emits methane gas.
Refrigeration and refrigeration systems emit fluorinated gases.
In 2020, natural gas consumption emissions from the residential and commercial sectors accounted for 79% of direct fossil fuels-related carbon dioxide emissions. The emission of greenhouse gases in the residential sector is 7.04 million tons of CO2eq in 2021 and has decreased by 4.9% or 0.36 million tons of CCO2eq since 2020. Fossil fuel combustion for residential and commercial buildings accounts for About 29 percent of US greenhouse gas emissions coming from fossil fuel combustion for residential and commercial buildings.
These emissions from residential places can be decreased by reducing solid waste sent to landfills and by capturing and using methane in a beneficial way produced from these landfills.
There are two main ways to reduce emissions associated with buildings: (1) reducing the energy required for buildings in use and (2) reducing/reducing the materials and energy produced in the building.
Agriculture produces large amounts of greenhouse gases, which contribute significantly to global warming and climate change. On the other hand, agricultural activities, land, and rice cultivation contribute about 30 percent of greenhouse gas emissions, mainly from toxic fertilizers, pesticides, and animal waste. Livestock emissions (CH4) and organic fertilizers and waste (N2O) represent the most significant sources, accounting for 65 percent of global agricultural emissions.
Carbon dioxide emissions associated with agriculture account for about 24% of global emissions.
Methane is produced by internal fermentation during animal digestion and is released through belches. It can also get rid of manure and organic waste stored in fields.
Between 2001 and 2011, global agricultural and livestock production emissions grew by 14 percent.
Forests surround about 30% of the entire earth’s surface. Forests account for 6% of global emissions. Forests are a source and sink of various greenhouse gases, including carbon dioxide (CO2), exchanged during biological processes such as photosynthesis, respiration, and decomposition. Methane (CH4) from anaerobic decomposition processes and nitrous oxide (N2O) is released in the stream during the nitrogen cycle.
A study was conducted between 2005 and 2010 to estimate greenhouse gas emissions from deforestation in 74 developing countries covering 2.2 billion hectares of forest. Annually the estimated emission from these countries was 2.1 billion tons of carbon dioxide, 53% of which was from wood harvesting, 17% from forest fires, and 30% from wood fuel harvesting.
Cutting down forests or forest fires releases the natural carbon stored in the trees, plants, and their soil, preventing further carbon dioxide absorption in the future. About 30% of all CO2 emissions have come from deforestation since 1850.
In North America and Eurasia, deforestation, up to alarming levels, has led to extremely hot weather. There are three possible ways to compensate for these losses, plant more and more trees and ensure the natural restoration of forests and ecosystems.
There is a whole family of greenhouse gases (GHGs). But the critical thing to remember is that not everyone is “created equal.” Whether it is possible to remove the carbon already emitted from the atmosphere or not, preventing global warming requires reducing greenhouse gas emissions. Otherwise, the adverse effects of global warming will be in the form of a hot climate, rising sea levels, the extinction of plants and animals, and increased ocean acidification.