The Greenhouse Effect
What is the main source of energy that warms Earth?
The Sun
What is a gas that absorbs and re-radiates infrared energy called?
A greenhouse gas
Does burning gasoline release greenhouse gases?
Yes
Which greenhouse effect is necessary for life: natural or enhanced?
Natural greenhouse effect
Why does Earth need the natural greenhouse effect?
It helps keep Earth warm enough for life.
What does sunlight do when it reaches Earth's surface?
It warms the land and oceans.
What greenhouse gas is released when fossil fuels are burned?
Carbon dioxide (CO₂)
What greenhouse gas is commonly released when gasoline and diesel are burned?
Carbon dioxide
The natural greenhouse effect helps keep Earth __________.
Warm
What happens to Earth when the land and oceans absorb energy from the Sun?
They become warmer.
What type of radiation does Earth release as heat?
Infrared radiation
Name one greenhouse gas besides carbon dioxide.
Methane, nitrous oxide, water vapour, or ozone
Name one human activity that can increase greenhouse gases.
Burning fossil fuels, deforestation, burning forests, farming, livestock, landfills, or industrial activities.
What causes the enhanced greenhouse effect?
Higher concentrations of greenhouse gases, largely from human activities.
After Earth becomes warm, what happens to some of the energy?
They become warmer.
What happens when greenhouse gases absorb some infrared radiation?
They re-radiate the energy in different directions.
Which greenhouse gas is the most abundant?
Water vapour
How can cutting down forests increase carbon dioxide?
Cutting or burning trees can release carbon dioxide, and there are fewer trees to absorb it.
True or False: The natural greenhouse effect is harmful and should completely disappear.
False
What happens to some infrared radiation after greenhouse gases absorb it?
It is re-radiated, and some returns toward Earth's surface.
Put these events in the correct order: Earth releases infrared radiation; sunlight reaches Earth; greenhouse gases absorb some heat; Earth becomes warmer.
Sunlight reaches Earth → Earth becomes warmer → Earth releases infrared radiation → greenhouse gases absorb some heat.
Which greenhouse gas can come from livestock, landfills, and rice production?
Methane (CH₄)
Why can using large amounts of coal, oil, and natural gas contribute to the enhanced greenhouse effect?
Burning them releases greenhouse gases such as carbon dioxide, causing more heat to be retained.
What is one important difference between the natural and enhanced greenhouse effects?
The natural greenhouse effect helps keep Earth warm, while the enhanced greenhouse effect results from increased greenhouse gases and causes more heat to be retained.
Why can an increase in greenhouse gases lead to global warming?
More greenhouse gases can cause more heat to be retained in Earth's climate system, contributing to long-term warming.