Climate Change From The Start Of The Quaternary Period And The Consequences Of Climate Change

Question 1

What are glacials

Answer 1

• historic cold periods associated with the build-up of snow, ice, the growth of ice sheets and glaciers

Question 2

What are inter-glacials

Answer 2

Historic warm periods in-between glacial periods where conditions were much the same as today

Question 3

What and when was the Little Ice Age

Answer 3

• 1300-1870
• a period of time when parts of Europe and Northern America experienced much colder winters than today
• coldest periods being 15th and 17th

Question 4

What were the consequences of the Little ice Age (6)

Answer 4

• The price of grain increased and vineyards in Europe became unproductive
• Ice land surrounded by sea ice = prevented ships landing and crops were failing = almost half the population left (emigrated)
• The sea froze around parts of UK
• regular winter ‘Frost Fairs’ were held on frozen river Thames
• In Northern Europe, rivers froze and food supplies became limited = famine
• effects lingered until beginning of 19th century

Question 5

What and when was the Medieval warm period

Answer 5

• it was associated with an unusual temp rise roughly between 750 and 1350 AD
• available evidence suggests that at times, som regions experienced temps exceeding those recorded during the period between 1960 and 1990

Question 6

Where can we find evidence for global warming

Answer 6

• Global temp data
• Ice cores
• Tree rings
• Paintings and diaries

Question 7

How does the Global temp data show evidence for climate change

Answer 7

• maps produced by NASA by using data collected over 1000 ground weather stations + satellite info
• there’s a warming trend for most of the world
• the warming is consistent with earlier maps produced over several decades
• avg global temps has increased by 0.6’C since 1950 and 0.85’C since 1880

Question 8

Why might the maps produced by NASA not necessarily be accurate

Answer 8

• weather stations are not evenly distributed across the world and some regions (especially Africa)
• therefore the maps aren’t absolutely accurate and reliable

Question 9

How can ice cores be used to show evidence for climate change

Answer 9

• extracted from Antarctic and Greenland
• when snow falls in polar environments, it builds up slowly, year by year
• buried layers of snow are compressed and gradually turned into ice
• scientists can drill to deep ice and extract cylindrical cores from ice, and then dated accurately
• they date them by analysing the trapped water molecules, then calculating the temp of the atmosphere when the snow fell
• this info can be used to create graphs from the past 400,000 years —> which show fluctuating temps
• this indicates past glacial and inter-glacial periods

Question 10

How thick and old is the Antarctic ice sheet

Answer 10

• 5km thick in some areas
• the eldest ice at it’s base is thought to be 800,000 yrs old

Question 11

How do tree rings show evidence of climate change

Answer 11

• every year, the growth of a tree is shown by a single ring
• if the ring is narrow it indicates a cooler drier year
• if it’s thicker it means the temp was warmer and wetter
• these patterns of growth are used to produce tree ring timescales, which give accurate climate info

Question 12

How do paintings and diaries show evidence for climate change

Answer 12

• Ancient cave paintings of animals in France and Spain depict nature as it was between 40, 000 and 11, 000 years ago, a period of time when the climate change significantly.
• most evidence from little Ice Age comes from diaries and observations made at the time
• paintings and drawings of ice fairs and markets on the river Thames when it froze —> indicate Little Ice Age

Question 13

What is the weakness with paintings and diaries for evidence of climate change

Answer 13

• it’s difficult to date accurately when cave paintings were drawn
• person accounts can lack objective accuracy

Question 14

What are some of the natural causes of climate change

Answer 14

• Greenhouse effect
• Milankovitch cycles (Orbital forcing): Eccentricity, axial tilt, precession
• Volcanic activity
• solar forcing

Question 15

what is the greenhouse effect is

Answer 15

• natural phenomenon
• maintains 15’C avg temp in lower atmosphere

Question 16

Explain how the greenhouse effect works

Answer 16

• sun emits short wavelength radiation, greenhouse gases can’t absorb it
• the earth reflects these wavelengths as long wavelength radiation which the greenhouse gases can absorb
• They then re-radiate it in all directions-including back towards earth
• The long wave radiation is thermal radiation, so it results in warming of the surface of the Earth. This is the greenhouse effect

Question 17

Explain how the Milankovitch cycles influence the Earth’s climate

Answer 17

—> Eccentricity:
- the Earths orbit
- when it’s more elliptical shaped = warmer periods
- when it’s more circular shaped = cooler periods
- a complete cycle take 100 000 years

—> Axial Tilt
- some parts get more intense solar radiation then others
- A greater degree of tilt = high avg. temp
- tilt of Earth moves back and forth over a period of 41, 000 years

—> Precession
- the Earth’s wobble
- 1 complete wobble takes 26, 000 years
- can cause very long days and very long nights

Question 18

How does volcanic activity influence climate change

Answer 18

• produces Ash and SO2
• Ash: ash clouds go high into atmosphere = block solar radiation = leading to worldwide cooling for up to 2 yrs
• SO2: SO2 gas turns into sulphuric acid particles in atmosphere = reflects sun’s rays = reducing solar radiation

Question 19

How does solar forcing influence climate change

Answer 19

• sun spots: dark patches on sun’s surface = indicate higher solar out put
• sun’s energy output isn’t constant
• periods when the sun’s activity is high correlates to warm climatic periods
• periods when the sun’s activity is low correlates to cooler climatic periods

Question 20

What were the causes of the Medieval warming Period

Answer 20

• increase in solar radiation and decrease in volcanic eruptions
• The increase in solar radiation modified the atmospheric pressure system over the North Atlantic Ocean,
• which brought warmer and wetter conditions over Northern Europe and most of north-eastern part of North American continent (including Greenland).

Question 21

What were the cause of the Little Ice age

Answer 21

• The weak sun in the 17th Ventura ray coincided with the little Ice Age
• Throughout the Little Ice Age, the world also experienced heightened Volcanic activity

Question 22

What are the sources of Carbon dioxide

Answer 22

• burning of fossil fuels
• Deforestation (burning wood)
• Industrial processes (e.g. making cement)

Question 23

What are the sources of Methane, CH4

Answer 23

• emitted from livestock and rice cultivation
• decay of organic waste in landfill sites

Question 24

What are the sources of Nitrous oxides, NOx

Answer 24

• vehicle exhausts
• agriculture and industrial processes

Question 25

What are the social consequences of climate change

Answer 25

• 600 million people live in coastal areas that are less than 10m above sea level
• people living in vulnerable areas may have to move home or even move to different countries. Some small islands states such as Tuvalu and Vanuatu are particularly at risk
• people may suffer from increased flooding and storm damage
• people may lose their jobs, e.g. fishing or tourism, so will have to learn new skills
• No. of environmental refugees will increase

Question 26

What are the economic consequences of climate change (6)

Answer 26

• Cities like London, New York, Venice may be affected by flooding
• valuable agricultural land may be lost to sea/polluted by sea water (in areas like India or China)
• harbours and ports may be affected —> impact on fishing and trade
• transport systems, such as railways, roads and airports might be damaged or destroyed
• valuable land and property will need expensive coastal protection measurements
• countries that depend on coastal tourism as main source of income may have beaches eroded or flooded —> forcing hotels to close and reducing tourism

Question 27

What are the environmental consequences of climate change

Answer 27

• fresh water sources might be contaminated by salty seawater: salinisation
• damage could occur to coastal ecosystems such as mangrove swamps, which form natural barriers to storms
• damage to coral reefs by storms and powerful waves will affect fish breeding grounds and ecosystems
• The IPCC estimates that up to 33% of coastal land and wetlands could be lost in the next 100 yrs
• Harbours may become blocked by sediment due to increased rates of coastal erosion