Match the following description to the event.

• a phenomenon showing a gradual increase of Earth's temperature due to unnaturally high levels of CO₂

• pollution

• a contamination of air dues to introduction of pollutants/chemicals

• ocean acidfication

• a phenomenon that increases ocean water acidity by lowering its pH due to high levels of CO₂

• global warming

• a natural phenomenon where greenhouses gases, like CO₂, traps sunlight and wams the planet

• greenhouse

How does carbon get from animals and back into the atmosphere? (CHOOSE ALL THAT APPLY)

• Respiration (breathing)

• After they die, they are broken down by decomposers

• Photosynthesis

• None of these

What do 'plants' do with the carbon they receive?

• They turn it into water

• They don't need carbon

• They turn it into food by photosynthesis

• They keep it forever

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

• Water
• Atmosphere
• Sun
• Air

Combustion is another word for _______________.

• a train
• a bus
• a dog
• burning

Carbon is used in the process called __________ by plants and algae to make food and the building blocks for growth.

• carbon cycle

• life

• photosynthesis

• decomposition

How do plants affect the air that animals and people breathe?

• Plants use oxygen from the air to make their own food

• Plants release pollution into the air

• Plants take in carbon dioxide and release oxygen

• Plants take in oxygen and release carbon dioxide

This image demonstrates that...

• There is a direct correlation with the atmospheric CO₂ and the CO₂ in seawater

• That pH of the ocean increases as the atmospheric CO₂ increases

• That there is no correlation between pH of the ocean and atmospheric CO₂

Which is a MAJOR cause of acid rain?

• spraying pesticides on crops

• burning fossil fuels for energy

• dumping sewage in rivers

• using Nuclear power stations

The diagram represents solar energy that is absorbed by Earth's land and water surfaces and is changed into heat that radiates back into the atmosphere.What is this process called?

• ozone
• radiation
• greenhouse effect
• evaporation