climate change

Question 1

what is climate change

Answer 1

Climate change is very long term shifts in weather patterns. The most important variable is changes in temperature.

Question 2

evidence of climate change:

Answer 2

• sea levels rise
• ice melting
• increased frequency of flooding + drought
• temperature increase in atmosphere + oceans
• decline in some species
• migration of biodiversity poleward

Question 3

how many cm has average global sea level risen in the last 100 years

Answer 3

between 10 and 20cm

Question 4

what are the 2 reasons why sea levels have risen?

Answer 4

1. when temperatures rise the freshwater stored in the ice sheets melt. This water is stored in the form of glaciers and ice caps. This water will then flow into the sea.
2. when the ocean water warms it expands. This is called thermal expansion

Question 5

3 natural causes of climate change:

Answer 5

• solar activity
• orbital changes
• volcanic activity

Question 6

what is a sunspot?

Answer 6

a dark patch that appears from time to time on the surface of the sun. Sunspots are areas of more intense energy (solar flare)

Question 7

what are 3 types of orbital changes?

Answer 7

• axial tilt
• precession
• eccentricity

Question 8

what is axial tilt?

Answer 8

• earth spins on its axis causing night and day
• over a period of 41,000 years the tilt of the earth moves back and forth between 21.5 and 24.5 degrees

Question 9

what is precession?

Answer 9

• the ‘wobble’ of the earth
• one complete wobble takes about 26,000 years
• the earths ‘wobble’ can give areas (such as Norway) long days and long nights at certain times of year

Question 10

what is eccentricity?

Answer 10

• path of the earth as it orbits the sun
• earths orbit can change from circular to elliptical (rugby ball shaped)
• complete cycle occurs every 100,000 years

Question 11

if the earths orbit is closer to the sun what will this mean for tis climate?

Answer 11

increased temperatures

Question 12

what is a short term impact of volcanic activity (climate change)

Answer 12

volcanic ash can block out the sun, reducing temperatures on earth

Question 13

what is a long term impact of volcanic activity (climate change)

Answer 13

• fine droplets form as a result of the conversion of sulphur dioxide to sulphuric acid
• this acid acts like tiny mirror reflecting radiation from the sun

Question 14

sources of greenhouse gas emissions

Answer 14

• fossil fuels
• deforestation
• agriculture

Question 15

why is combustion of fossil fuels happening?

Answer 15

• population growth
  -> more energy demand
  -> more fossil fuels burnt and released into atmosphere

Question 16

what is the link between burning fossil fuels and increased temp?

Answer 16

produce CO2 adds to the enhanced greenhouse affect

Question 17

why is changing agriculture happening?

Answer 17

• increased population
  -> more food needed to feed the growing population

Question 18

what is the link between changing agriculture and increased temp?

Answer 18

produces 20% of the greenhouse gas emissions especially methane from cattle/paddy fields

Question 19

why is deforestation happening?

Answer 19

• agriculture - crops/livestock
• logging - wood/paper
• roads - access
• urbanisation

Question 20

what is the link between deforestation and increased temp?

Answer 20

deforestation - trees can’t absorb CO2 -> more CO2 in atmosphere