Mastery Check #4 - climate change
The greenhouse effect important because it keeps the Earth warm enough for life to exist. The moon doesn't have an atmosphere or greenhouse gases so it gets really cold at night and really hot during the day. Greenhouse gases trap heat that is trying to escape the Earth. The picture to the right shows this. The greenhouse gases are carbon dioxide, methane, water, ozone, and nitrous oxide.
|
How is carbon dioxide cycled into and out of the atmosphere?
The following process either release carbon dioxide into the atmosphere or remove it from the atmosphere:
- Plant photosynthesis - plants take in carbon dioxide and turn it into glucose sugar. They remove CO2 from the atomsphere.
- Animal respiration - animals take the sugars and convert it back into carbon dioxide which they then breath out. They release CO2 into the atmosphere.
- These two processes both happen at the same rate so they balance each other out.
- Formation of rocks - Carbon dioxide from the atmosphere is absorbed into the ocean and the plants and animals in the ocean then incorporate it into their bodies. When they die they sink to the ocean floor and form rocks.
- Volcanic eruptions - the rocks that are storing carbon melt and release the carbon dioxide back into the atmosphere.
- The two processes both happen at the same rate so they also balance each other out.
- Formation of fossil fuels - plants take in carbon dioxide for photosynthesis. When they die, they are then converted into fossil fuels. Fossil fuel formation has removed a lot of CO2 from the atmosphere and stored it over millions of years.
- Burning fossil fuels - when we burn fossil fuels we release the CO2 back into the atmosphere.
- Because fossil fuels from so slowly and we burn them so quickly, the CO2 levels in the atmosphere are increasing a lot.
How does increasing carbon dioxide level affect climate?
Because carbon dioxide is a greenhouse gas, it is trapping a lot of heat on the Earth. Our climate is gradually warming because of increased CO2 levels. Look at the data on this NASA website to see some of the evidence of a warming climate. These are some of the evidences:
- Warmer ocean and air temperatures
- Melting ice caps
- Melting glaciers
- Rising sea levels
- More intense storms
- More intense droughts and wildfires
- More flooding
- Ocean acidification