7.4 Flashcards
What is the greenhouse effect?
The greenhouse effect is when greenhouse gases trap some of the energy from the sun, helping to maintain Earth’s warm temperatures.
What would Earth’s average temperature be without the greenhouse effect?
Without the greenhouse effect, the average temperature on Earth would be about –18°C, making life as we know it impossible.
What human activities have increased greenhouse gases (GHGs)?
Burning fossil fuels, deforestation, travel, industrial waste, and an increase in the human population.
What are the main greenhouse gases (GHGs) that have increased?
The main GHGs are N₂O (nitrous oxide), CO₂ (carbon dioxide), and H₂O (water vapor).
What happens when greenhouse gases increase?
Increased greenhouse gases trap more heat, causing Earth to heat up more than expected.
What is the term for the increased warming of Earth due to higher levels of greenhouse gases?
The enhanced greenhouse effect.
What is a source of carbon emissions in living organisms?
Cellular respiration, where glucose is converted into energy, producing carbon dioxide as a byproduct.
How do fossil fuels contribute to carbon emissions?
The combustion of fossil fuels releases increased levels of carbon dioxide, with industrial buildings burning more fossil fuels contributing to this rise.
How do ice cores help scientists study past air conditions?
Dust, gases, and other substances trapped in ice provide information about the air at the time, helping scientists track past air temperatures and carbon dioxide concentrations.
What is methane’s role in the enhanced greenhouse effect?
Methane contributes to the enhanced greenhouse effect and accounts for about 20% of the greenhouse gases produced.
What are the main sources of methane emissions?
Methane is produced through agriculture (e.g., cattle), wetlands, fossil fuel production and use, biomass burning, and natural emissions like melting permafrost.
What is permafrost?
Permafrost is ground that has been frozen for at least 2 continuous years.
