4.22 DOL

The greenhouse effect is caused by

• more heat arriving at the Earth from the sun

• gases in the air trapping heat released by the Earth

• the Earth releasing more heat at night

• The sun radiating towards Earth only

A decrease in forest land results in a net __________ of CO₂ in the atmosphere.

• decrease

• increase

• no change

• fluctuation

Which of the following activities contributes to the most carbon emissions globally?

• Deforestation

• Burning Fossil Fuels

• Agriculture

• Respiration

Increased carbon dioxide may cause global warming by

• allowing more sunlight into the atmosphere

• reflecting more sunlight from clouds

• reducing the amount of oxygen in the air

• trapping more heat in the atmosphere

Which of the following is best conclusion that can be made from this graph?

• atmospheric carbon dioxide levels have been decreasing since 1960

• humans have been working hard to decrease carbon dioxide levels

• Hawaii has a lot of carbon dioxide

• atmospheric carbon levels have increased steadily since 1960

Which is a natural source of greenhouse gases?

• aerosols

• deforestation

• volcanic eruptions

• burning fossil fuels

Which of the following is contributing to an INCREASE in carbon dioxide in the atmosphere?

• deforestation

• oceans

• photosynthesis

• the loss of animal species

• all of the above