Earth 2 Flashcards
What is the natural greenhouse effect?
The natural greenhouse effect is a process where shortwave radiation from the sun is absorbed and reradiated as longwave radiation by Earth’s surface and greenhouse gases. This process warms the planet by approximately 33°C, making life on Earth possible.
What are greenhouse gases (GHGs)?
Greenhouse gases are gases that absorb and emit longwave radiation. Key GHGs include water vapor, carbon dioxide, methane, nitrous oxide, ozone, and chlorofluorocarbons (CFCs).
Why are greenhouse gases important for Earth’s temperature?
Without greenhouse gases, Earth’s average temperature would be -18°C. They help retain heat, maintaining a current average temperature of 15°C.
What is the global warming potential (GWP)?
GWP is a measure of how much energy a greenhouse gas absorbs compared to carbon dioxide (CO2) over a specific period, typically 100 years. It helps compare the warming impact of different gases.
Which greenhouse gases have the highest warming effect within the atmosphere?
Water vapor and carbon dioxide have the largest warming effects. Water vapor is removed via precipitation, while carbon dioxide is absorbed by photosynthesis and oceans.
What are the natural sources of methane and nitrous oxide?
- Methane: Emitted during bacterial decomposition in swamps, wetlands, and animal digestion.
- Nitrous Oxide: Emitted by soil microbes and during lightning strikes.
What is the enhanced greenhouse effect?
The enhanced greenhouse effect refers to the increased warming of Earth’s atmosphere due to higher emissions of greenhouse gases from human activities like industry, agriculture, and transportation.
How do man-made gases like CFCs compare to natural greenhouse gases?
CFCs are thousands of times more potent than carbon dioxide but exist in very small quantities. They also remain in the atmosphere for tens of thousands of years.
What role did Eunice Newton Foote play in understanding greenhouse gases?
She discovered that carbon dioxide has high heating potential and takes longer to cool down. Her work was an early step in understanding the greenhouse effect.
How have atmospheric CO2 levels changed over time?
Atmospheric CO2 concentrations have steadily increased, largely due to human activities like burning fossil fuels. CO2 accumulates in the atmosphere because it has a long lifetime.
What are the main human sources of greenhouse gases?
Energy production, industry, agriculture, and transportation are the most significant emitters of greenhouse gases.
What is the relationship between economic development and greenhouse gas emissions?
High-income countries (HICs) historically emitted the most greenhouse gases due to industrialization, while middle- and low-income countries are increasing their emissions as they develop.
How do methane and carbon dioxide differ in their impact on the greenhouse effect?
Methane absorbs more heat than carbon dioxide but has a shorter atmospheric lifetime. Carbon dioxide is less potent but stays in the atmosphere much longer.
