Earth Systems and Feedback Loops

A thermostat in a central heating system can determine the temperature of your living room. It switches the air conditioner on when the temperature increases to a predetermined level and shuts it off when it cools to another level. The room temperature remains within a comfortable level regardless of the temperature outside.

• Positive Feedback Loop

• Negative Feedback Loop

Tags

NGSS.MS-PS3-4

NGSS.MS-PS3-5

In some developing countries poverty causes illness and contributes to poor standards of education. In the absence of knowledge of family planning methods and hygiene, this contributes to population growth and illness, adding further to the causes of poverty; “a vicious circle of poverty.”

• Positive Feedback Loop

• Negative Feedback Loop

Some organisms have internal feedback systems, physiological changes occurring prevent breeding when population densities are high and promote breeding when population densities are low.

• Positive Feedback Loop

• Negative Feedback Loop

Tags

NGSS.HS-LS1-3

As the Earth warms, ice cover melts, exposing soil or water. Albedo decreases. More energy is absorbed by the Earth’s surface. Global temperature rises. More ice melts.

• Positive Feedback Loop

• Negative Feedback Loop

Tags

NGSS.HS-ESS2-2

As the Earth warms, upper layers of permafrost melt, producing waterlogged soil above frozen ground. Methane gas is released into the environment. The greenhouse effect is enhanced. The Earth warms, melting more permafrost.

• Positive Feedback Loop

• Negative Feedback Loop

Tags

NGSS.HS-ESS2-2

A organization posts an advertisement with a very "click-baity" title and image on a social media platform. The title and image draw in people to click on the ad. As the ad receives more views, the algorithm shows the ad to more people.

• Positive Feedback Loop

• Negative Feedback Loop

As the Earth warms, increased evaporation produces more clouds. Clouds increase albedo, reflecting more light away from the Earth. The temperature falls. Rates of evaporation fall.

• Positive Feedback Loop

• Negative Feedback Loop

Tags

NGSS.HS-ESS2-2

A democratic country with 4 political parties has extreme left, moderate left, moderate right, and extreme right parties. The social policies of the parties on the left result in a more equitable and socially stable society, but result in economic turmoil. The economic policies of the parties on the right result in widespread economic prosperity, but result in social unrest. Every 2 years the people vote on one of the 4 parties to improve economic or social quality of their country (whichever is currently worse).

• Positive Feedback Loop

• Negative Feedback Loop