GEO QUIZ 2 Try 2

Global temperature anomaly: the difference between current global temperature over 1850 to

1900

- Humans hadn’t so dramatically affected the climate

Current Global temperature anomaly: +1.3 degrees celsius

- Includes all locations

Last Ice Age - 6 degrees celsius cooler than today

- Global warming is measured in ice age units

- 1.3 degrees celsius/ 6 degrees celsius = 20% of the size of change since the ice age

In the future: warming by 2100: 2-3 degrees celsius most likely

CO2

- In 1750: 250 ppm

- In 2022: 415 ppm

- Almosy 50% increase

Other Greenhouse gasses

- Methane

- Nitrous oxide

- Increases as well

Global Warming caused by increase in greenhouse gasses in atmosphere

CO2Sources

1. Fossil fuel burning → coal, oil, natural gas

2. Deforestation

Feedbacks in the Climate System

- Positive feedback: process that is self enhancing

- Sound → sound picked up by microphone → sound amplified by speaker →

sound

- Negative Feedback: self limiting process

Global Temperature controlled by balance between positive and negative feedback

Water Vapor Feedback: as global temperature increases, water vapor in the atmosphere increases

(water vapor is a greenhouse gas)

- Water Vapor → increase in water vapor → less longwave radiation escapes → water vap.

Ice Albedo Feedback (high albedo, lighter color)

- Warming → melt arctic sea ice → reduce albedo → increase shortwave absorbed →

warming

Feedbacks

- Positive: self enhancing cycles

- Negative: self limiting process

Clouds

- Low clouds; flat, close to the surface

- High clouds; thin, high in the atmosphere

Cloud feedback

- Warming → less low clouds → increase in shortwave radiation → warming (+)

- Shortwave radiation reflected off of low clouds

- Warming → more high clouds → reduce outgoing longwave radiation → warming (+)

- Long wave radiation absorbed outgoing by high clouds

Radiation Feedback

- warming → increase energy carried by longwave → more heat lost → less warming

(negative feedback)

- Amount of energy in an object's radiation increases w/ temp.

- Increase in earth temp. Means more energy lost via longwave

Positive and negative feedback will eventually balance

CO2: 280 → 415ppm

Temp: 1.3 degrees celsius warming

Climate Sensitivity: increase in temp. When CO2concentration doubles – 2-4.5 degrees celsius

Emissions: amount of CO2added to atmosphere each year = 50 gigatons per year