Greenhouse Gases

Question 1

GREENHOUSE GAS DEFINITION

Answer 1

Greenhouse gas is defined as any gas that has the property of absorbing infrared radiation (net heat energy) emitted from Earth’s surface and reradiating it back to Earth’s surface, thus contributing to the greenhouse effect. Carbon dioxide, methane, and water vapour are the most important greenhouse gases

Greenhouse gases are gases that can trap heat. They get their name from greenhouses. A greenhouse is full of windows that let in sunlight. That sunlight creates warmth. The big trick of a greenhouse is that it doesn’t let that warmth escape.

That’s exactly how greenhouse gases act. They let sunlight pass through the atmosphere, but they prevent the heat that the sunlight brings from leaving the atmosphere. Overall, greenhouse gases are a good thing. Without them, our planet would be too cold, and life as we know it would not exist. But there can be too much of a good thing. Scientists are worried that human activities are adding too much of these gases to the atmosphere.

Question 2

GREENHOUSE EFFECT DEFINITION

Answer 2

The greenhouse effect is a natural process that warms the Earth’s surface.

When the Sun’s energy reaches the Earth’s atmosphere, some of it is reflected back to
space and the rest is absorbed and re-radiated by greenhouse gases.

The absorbed energy warms the atmosphere and the surface of the Earth.

Question 3

Types of gases

Answer 3

Water Vapour -
GOOD: This is water in gas form. It is high in the atmosphere and condenses back into liquid water when it rains back down on earth. BAD: Water vapour blocks heat from escaping the atmosphere, and warmer air holds more water vapour. As earth heats up more water vapour can trap more heat.

Carbon Dioxide
GOOD: Made up of carbon and oxygen and is all around us naturally. Plants use it to make oxygen for humans and animals to survive.
BAD: CO2 is released when fossil fuels like coal and oil are burnt. The most human contributor to global warming.

Methane
GOOD: Methane is made of carbon and hydrogen. It is a normal gas that comes from raising cattle, growing rice and wetlands.
BAD: It traps a lot of heat. Scientists consider it the second most human caused contributor to global warming of all the greenhouse gases.