Fill in the blank: Volcanic eruptions add ____, dust, carbon dioxide, and sulfur dioxide to the atmosphere.

• ash

• water

• oxygen

• nitrogen

Fill in the blank: Carbon dioxide reduces the amount of energy that leaves the Earth system because it redirects outgoing energy. When more energy enters than exits, there will be more energy in the system overall, and Earth will ____.

• warm

• cool

• shrink

• darken

Fill in the blank: Sulfur dioxide reduces the amount of energy that enters the Earth system because it redirects incoming energy from sunlight back to ____.

• outer space

• the ocean

• the ground

• the atmosphere

Fill in the blank: An increase in sulfur dioxide results in cooling because sulfur dioxide causes more energy to leave, and that means less energy enters than exits the Earth system for a period of time. There will be less energy in the system overall, and Earth will ____.

• cool

• warm

• expand

• brighten

Fill in the blank: While human activities are causing the current long-term trend of increasing temperatures, in the short term, other factors can have smaller effects on the ____.

• climate

• population

• economy

• vegetation

Fill in the blank: Large volcanic eruptions don’t have the large, long-term effects that human activities like driving cars and cutting down trees do, but they may temporarily affect ____.

• climate

• gravity

• magnetism

• ocean tides

Fill in the blank: Even though volcanic eruptions are NOT the cause of the long-term trend of increasing temperatures that has been occurring since 1880, it is also important for scientists to understand factors that influence climate in smaller ways or for shorter amounts of time. Smaller changes to temperature can temporarily affect things like weather patterns and the stability of ecosystems and change the size of ____.

• glaciers

• deserts

• oceans

• mountains

Fill in the blank: If the climate changes, some populations might die or move out of an ecosystem. As a result, the populations of animals that eat those other organisms would also ____.

• decrease

• increase

• stay the same

• become healthier

Fill in the blank: Scientists must carefully consider all available evidence before making arguments about a ____.

Fill in the blank: Discussing evidence and ideas with others helps build new ____.

• understanding

• walls

• problems

• confusion