Climate Change

Question 1

What is paleoclimatology?

Answer 1

the study of the Earth’s past climates through proxy methods

Question 2

What are the three methods for long-term climate reconstruction?

Answer 2

• isotope analysis
• ice cores
• ocean sediment core

Question 3

What is significant about the climate of the past 70 million years (3)?

Answer 3

• scientists have been able to reliably recreate climate
• continents have been stable throughout this time
• relatively rapid warming of the atmosphere

Question 4

What are some characteristics of the climate of the past 70 million years (3)?

Answer 4

• warmer
• tropical environments extended further
• cooling trend 50 million years ago

Question 5

What is significant about the climate of the past five million years (3)?

Answer 5

• oversaw the evolution of modern humans
• rise of agriculture and civilizations
• included an ice age

Question 6

What is significant about the climate of the past 20,000 years?

Answer 6

there have been more sources of data to analyze climate

Question 7

What is dendrochronology (4)?

Answer 7

• each ring represents a year of growth
• the thicker the ring, the wetter the conditions
• the thinner the ring, the dryer the conditions
• scars form forest fires

Question 8

What are the mechanisms of natural climate change (4)?

Answer 8

• solar variability
• Earth’s orbital cycles
• continental position and topography
• atmospheric gases and aerosols

Question 9

How does solar variablity affect climate change (4)?

Answer 9

• variations in amount of energy coming into Earth’s system
• solar output has increased by 1/3
• changes in the sun’s magnetic field
• susnpot activity

Question 10

How does Earth’s orbital cycles affect climate change (5)?

Answer 10

• distance between Earth and sun varies
• elliptical orbit around sun varies
• shape of ellipse varies
• Earth’s orientation towards sun
• axial tilt varies

Question 11

How does continental position and topograpy affect climate change (4)?

Answer 11

• composition of continents impacts atmospheric and oceanic circulation
• example: formation of Himalyan Mountains affects jet stream and rain shadow
• example: formation of Panamanian Bridge prevents ocean flow
• position and structure impacts Earth’s albedo

Question 12

How do atmospheric gases and aerosols affect climate change (3)?

Answer 12

• more carbon dioxide = warmer
• less carbon dioxide = cooler
• aerosols cause cooler conditions

Question 13

What is feedback (3)?

Answer 13

• feedback: systems produce outputs that influence their own operations
• positive feedback: feedback amplifies system changes; destabilizes system
• negative feedback: a reduction in system changes; stabilizes system

Question 14

What are some examples of feedback that impact climate (2)?

Answer 14

• ice-albedo feedback

- water vapor feedback

Question 15

What is the carbon budget?

Answer 15

the exchange of carbon between sources and sinks in all of Earth’s spheres

Question 16

What is the Carbon Cycle (3)?

Answer 16

• some processes remove carbon from the atmosphere (photosynthesis)
• some add carbon to the atmosphere (respiration and decomposition)
• must remain balanced

Question 17

What are some human impacts on the Carbon Cycle (2)?

Answer 17

• clearing forests: decreases carbon sinks

- industrial revolution: burning of fossil fuels

Question 18

What is the Keeling Curve?

Answer 18

• shows increase of carbon dioxide since 1955

- fluctuation caused by seasonality and photosynthesis

Question 19

How do oceans affect the carbon cycle (5)?

Answer 19

• absorption of carbon by ocean results in smaller than expected amount of CO2 in atmosphere
• absorption causes formation of carbonic acid in ocean
• ocean acidity negatively impacts marine life
• the world’s oceans have absorbed about 50% of atmospheric carbon
• as the ocean’s temperature increases, its ability to dissolve carbon decreases

Question 20

How do plants affect the carbon cycle?

Answer 20

• plants grow at a quicker rate and store more carbon

- but as temperature increases, photosynthesis decreases

Question 21

What serves as evidence for present climate change (5)?

Answer 21

• sources of climate data
• rising temperatures
• melting ice
• rising sea levels
• increased atmospheric water vapor

Question 22

What are some sources of climate data (4)?

Answer 22

• weather data
• satellites
• weather balloons, ships, buoys, etc.
• aircrafts

Question 23

How do rising temperatures explain climate change (2)?

Answer 23

• warmest time in last 120,000 years

- increse in 20th century temperature happened faster than any other increase in the last 1,000 years

Question 24

How does melting ice explain climate change (3)?

Answer 24

• melting sea ice does not increase sea level, but exposes lower albedo ocean water, resulting in increasing temperatures
• glacial ice is decreasing in Antarctice and Greenland
• permafrost has been thawing

Question 25

How do rising sea levels explain climate change (2)?

Answer 25

- by-product of melting ice in polar environments | - happening faster than previously thought

Question 26

How does increased atmospheric water vapor explain climate change (3)?

Answer 26

- increasing since the 1970s - by-product of increasing temperature - results in more frequent and extreme weather events

Question 27

What is the primary cause of worldwide temperature increases?

Answer 27

increase of greenhouse gasses in atmosphere

Question 28

How do greenhouse gasses affect climate change (2)?

Answer 28

- higher levels of greenhouse gasses absorb more longwave radiation trying to exit Earth's atmosphere - contribution to climate change depends on type of gas and how long gas remains in atmosphere

Question 29

How has the increase in carbon dioxide contributed to climate change (3)?

Answer 29

- most prevalent of greenhouse gasses - lasts 50-100 years - primary sources: fossil fuels (70%), biomass burning, forest removal, industrial agriculture, cement production

Question 30

How has the increase in methane contributed to climate change?

Answer 30

- 2nd most prevalent - lasts about 12 years - traps more heat than CO2 - primary sources: livestock, mining coal, oil, natural gas, rice farming, burning vegetation

Question 31

How has the increase in nitrous oxide contributed to climate change?

Answer 31

- 3rd most prevalent - lasts about 120 years - primary sources: commercial agriculture (chemical fertilizer)