The Carbon Cycle

When humans burn fossil fuels, most of the carbon quickly enters the _______ as carbon dioxide

• water
• atmosphere
• sun
• air

Which of these does not add CO2 to the atmosphere

• cooking with gas
• planting trees
• burning wood
• riding in a bus

Combustion is another word for

• burning
• melting
• exploding
• incinerating 

How do living organisms return carbon to the atmosphere in the carbon cycle

• respiration and decomposition
• respiration and photosynthesis
• death
• burning

How does the carbon in grass become part of a living animal?

• by eating the grass
• It doesn't end up in the animal no matter what
• It ends up in its food chain
• It breathes in carbon given out by the plant

Why is the increase in greenhouse gasses an issue

• It causes climate change and increase in the global temperature 
• It can lead to a major increase in greenhouses
• It leads to more factories
• It causes a moajor decrease in people

What process keeps Earth's temperature suitable for life

• Convention currents
• Greenhouse Effect
• Albedo Effect
• Water Cycle

Why does too much carbon dioxide in the atmosphere cause climate change?

• It cools our planet
• Blocks out UV rays
• Traps heat and warms planet
• Lets light escape

Which of the following adds oxygen to the atmosphere

• forest fires
• photosynthesis
• weathering of rocks
• life processes of animals

Deforestation contributes to the greenhouse gasses by

• loss of trees that would otherwise remove carbon dioxide from the air
• as trees are cut, they release carbon dioxide
• increasing the amount of oxygen in the air