Earth's Natural Blanket
Our planet is a comfortable place to live, not too hot and not too cold. This is thanks to a natural process called the greenhouse effect. It works a bit like a greenhouse for plants.
The Natural Greenhouse Effect
1.Solar Radiation: Energy from the sun (solar radiation) travels through space and passes through our atmosphere.
2.Absorption: The Earth's surface absorbs this energy and heats up.
3.Infrared Radiation: The warmed Earth radiates some of this energy back outwards in the form of infrared radiation (which we feel as heat).
4.Trapping Heat: Certain gases in the atmosphere, called greenhouse gases, absorb this outgoing infrared radiation. They trap the heat and prevent it from escaping back into space, keeping the planet warm.
Without this natural greenhouse effect, the Earth would be a frozen, uninhabitable planet with an average temperature of about -18°C (0°F)!
The Greenhouse Gases
The main gases responsible for the greenhouse effect are:
Water Vapor (H₂O): The most abundant greenhouse gas.
Carbon Dioxide (CO₂): A natural part of the atmosphere, released by respiration and volcanoes, and absorbed by plants.
Methane (CH₄): Released by natural processes in wetlands and by the digestive processes of some animals.
The Enhanced Greenhouse Effect
The problem we face today is not the natural greenhouse effect, but the enhanced greenhouse effect caused by human activities.
Burning Fossil Fuels: Since the Industrial Revolution, humans have been burning huge amounts of fossil fuels (coal, oil, and natural gas) for energy. This process releases massive amounts of extra carbon dioxide (CO₂) into the atmosphere.
Deforestation: Cutting down forests reduces the number of trees available to absorb CO₂ from the atmosphere.
Agriculture: Raising livestock and certain farming practices release large amounts of methane.
By adding these extra greenhouse gases to the atmosphere, we are making the 'blanket' thicker. This traps more heat, causing the Earth's average temperature to rise.
Global Warming vs. Climate Change
These two terms are related but not the same.
Global Warming: Refers specifically to the long-term heating of Earth's climate system observed since the pre-industrial period due to human activities, primarily fossil fuel burning, which increases heat-trapping greenhouse gas levels in Earth's atmosphere. It is the 'fever' of the planet.
Climate Change: A much broader term that refers to the long-term changes in weather patterns and average conditions. Global warming is a major aspect of climate change, but climate change also includes changes in precipitation patterns, increased frequency of extreme weather events (like hurricanes, droughts, and heatwaves), and sea-level rise.