What is the Greenhouse Effect?
The greenhouse effect is a natural process where certain atmospheric gases absorb and re-emit infrared radiation from Earth's surface, trapping heat in the atmosphere and maintaining a habitable temperature. Without it, Earth's average temperature would be about -18°C instead of 15°C. This effect is driven by greenhouse gases that allow sunlight to pass through but prevent heat from escaping.
Key Atmospheric Gases Involved
The primary greenhouse gases include carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), and water vapor. CO2, from fossil fuel burning and deforestation, accounts for about 76% of human-induced warming. Methane, from agriculture and landfills, is 25 times more potent than CO2 over 100 years. These gases vary in concentration and longevity in the atmosphere, influencing the intensity of the effect.
Practical Example: Urban Heat Islands
In cities like Los Angeles, increased CO2 from vehicle emissions enhances the greenhouse effect, raising local temperatures by 1-3°C. This leads to more air conditioning use, creating a feedback loop. For instance, during heatwaves, trapped heat exacerbates urban heat islands, illustrating how elevated atmospheric gases amplify everyday climate impacts.
Importance and Real-World Applications
Understanding the greenhouse effect is crucial for addressing climate change, as rising gas concentrations from human activities intensify global warming, causing sea-level rise and extreme weather. Applications include emission reduction policies like the Paris Agreement, carbon capture technologies, and reforestation to sequester CO2, helping mitigate environmental risks.