What is global warming ?
Global warming is primarily driven by human activities that increase the concentration of greenhouse gasses (GHGs) in the atmosphere, trapping heat and causing Earth’s temperatures to rise. These activities, along with some natural factors, contribute to the overall warming effect. Here are the key causes:
We are burning coal, oil and natural gas for energy production, transportation and industrial processes that release large amounts of carbon dioxide (CO2), a major greenhouse gas. This is the single largest contributor to global warming.
- The burning of coal, oil, and gas for electricity and heat is responsible for about 25% of global greenhouse gas emissions.
- Vehicles powered by gasoline and diesel emit CO2 and other pollutants. This sector is responsible for nearly a quarter of global CO2 emissions.
- Trees absorb CO2 from the atmosphere, and when forests are cut down for agriculture, logging, or urban development, this carbon is released back into the atmosphere. Deforestation reduces the planet’s ability to absorb CO2, contributing to higher atmospheric levels.
- Converting forests into agricultural land (for crops or livestock) not only releases carbon but also alters ecosystems and biodiversity, further contributing to climate imbalances.
- The process of making cement releases CO2, as limestone (calcium carbonate) is heated to produce lime (calcium oxide). This accounts for around 8% of global CO2 emissions.
- Chemical Industry emit greenhouse gasses like methane (CH4), nitrous oxide (N2O), and fluorinated gasses (such as hydrofluorocarbons, perfluorocarbons, and sulfur hexafluoride) that have a much higher warming potential than CO2.
- Cows, sheep, and other ruminant animals produce methane during digestion, a process known as enteric fermentation. Methane is a potent greenhouse gas, with a warming potential more than 25 times that of CO2.
- Paddy fields for growing rice emit methane due to the anaerobic conditions in the waterlogged soils.
- The use of nitrogen-based fertilizers releases nitrous oxide (N2O), another powerful greenhouse gas, into the atmosphere.
- Decomposing organic waste in landfills produces methane, contributing significantly to global warming.
- In addition to emissions from burning fossil fuels, the process of extracting and refining oil and gas releases methane, a highly potent greenhouse gas.
- Methane can leak from pipelines, storage tanks, and oil/gas wells during the production and transportation of fossil fuels, contributing to the overall greenhouse effect.
- The global transportation sector, of cars and planes, brings combustion engines that burn fossil fuels, contributing significantly to CO2 emissions.
- Cities, with their asphalt roads, concrete buildings, and reduced greenery, absorb and retain more heat than rural areas, leading to localized warming (urban heat island effect). This increases energy demand for cooling, which in turn can lead to more fossil fuel Large volcanic eruptions that can release significant amounts of CO2 and other gasses into the atmosphere.
- However, over the long term, volcanic activity has a relatively minor impact on global warming compared to human activities.
The overwhelming cause of global warming is human activity, particularly the burning of fossil fuels, deforestation, industrial processes, use of cement to build buildings and roads and agricultural practices. While natural processes also play a role, they are minimal compared to the large-scale emissions of greenhouse gasses caused by modern society. Addressing these causes requires transitioning to renewable energy, reducing deforestation, improving energy efficiency, and adopting sustainable agricultural practices and sustainable use of construction materials for building better cities.
By Asha Bhansali